WorldWideScience

Sample records for permeability change implications

  1. Shear-induced Fracture Slip and Permeability Change. Implications for Long-term Performance of a Deep Geological Repository

    International Nuclear Information System (INIS)

    Min, Ki-Bok; Stephansson, Ove

    2009-03-01

    Opening of fractures induced by shear dilation or normal deformation can be a significant source of fracture permeability change in jointed rock, which is important for the performance assessment of geological repositories for spent nuclear fuel. As the repository generates heat and later cools the fluid-carrying ability of the rocks becomes a dynamic variable during the lifespan of the repository. Heating causes expansion of the rock close to the repository and, at the same time, contraction close to the surface. During the cooling phase of the repository, the opposite takes place. Heating and cooling together with the virgin stress can induce shear dilation of fractures and deformation zones and change the flow field around the repository. The objectives of this project are to examine the contribution of thermal stress to the shear slip of fracture in mid- and far-field around a KBS-3 type of repository and to investigate the effect of evolution of stress on the rock mass permeability. The first part of the study is about the evolution of thermal stresses in the rock during the lifetime of the repository. Critical sections of heat generated stresses around the repository are selected and classified. Fracture data from Forsmark is used to establish fracture network models (DFN) and the models are subjected to the sum of virgin stress and thermal stresses and the shear slip and related permeability change are studied. In the first part of this study, zones of fracture shear slip were examined by conducting a three-dimensional, thermo-mechanical analysis of a spent fuel repository model. Stress evolutions of importance for fracture shear slip are: (1) comparatively high horizontal compressive thermal stress at the repository level, (2) generation of vertical tensile thermal stress right above the repository, (3) horizontal tensile stress near the surface, which can induce tensile failure, and generation of shear stresses at the corners of the repository. In the

  2. Shear-induced Fracture Slip and Permeability Change. Implications for Long-term Performance of a Deep Geological Repository

    Energy Technology Data Exchange (ETDEWEB)

    Min, Ki-Bok (School of Civil, Environmental and Mining Engineering, Univ. of Adelaide, Adelaide (Australia)); Stephansson, Ove (Steph Rock Consulting AB, Berlin (Germany))

    2009-03-15

    Opening of fractures induced by shear dilation or normal deformation can be a significant source of fracture permeability change in jointed rock, which is important for the performance assessment of geological repositories for spent nuclear fuel. As the repository generates heat and later cools the fluid-carrying ability of the rocks becomes a dynamic variable during the lifespan of the repository. Heating causes expansion of the rock close to the repository and, at the same time, contraction close to the surface. During the cooling phase of the repository, the opposite takes place. Heating and cooling together with the virgin stress can induce shear dilation of fractures and deformation zones and change the flow field around the repository. The objectives of this project are to examine the contribution of thermal stress to the shear slip of fracture in mid- and far-field around a KBS-3 type of repository and to investigate the effect of evolution of stress on the rock mass permeability. The first part of the study is about the evolution of thermal stresses in the rock during the lifetime of the repository. Critical sections of heat generated stresses around the repository are selected and classified. Fracture data from Forsmark is used to establish fracture network models (DFN) and the models are subjected to the sum of virgin stress and thermal stresses and the shear slip and related permeability change are studied. In the first part of this study, zones of fracture shear slip were examined by conducting a three-dimensional, thermo-mechanical analysis of a spent fuel repository model. Stress evolutions of importance for fracture shear slip are: (1) comparatively high horizontal compressive thermal stress at the repository level, (2) generation of vertical tensile thermal stress right above the repository, (3) horizontal tensile stress near the surface, which can induce tensile failure, and generation of shear stresses at the corners of the repository. In the

  3. Permeability changes due to mineral diagenesis in fractured crust: implications for hydrothermal circulation at mid-ocean ridges

    Science.gov (United States)

    Fontaine, Fabrice Jh.; Rabinowicz, Michel; Boulègue, Jacques

    2001-01-01

    The hydrothermal processes at ridge crests have been extensively studied during the last two decades. Nevertheless, the reasons why hydrothermal fields are only occasionally found along some ridge segments remain a matter of debate. In the present study we relate this observation to the mineral precipitation induced by hydrothermal circulation. Our study is based on numerical models of convection inside a porous slot 1.5 km high, 2.25 km long and 120 m wide, where seawater is free to enter and exit at its top while the bottom is held at a constant temperature of 420°C. Since the fluid circulation is slow and the fissures in which seawater circulates are narrow, the reactions between seawater and the crust achieve local equilibrium. The rate of mineral precipitation or dissolution is proportional to the total derivative of the temperature with respect to time. Precipitation of minerals reduces the width of the fissures and thus percolation. Using conventional permeability versus porosity laws, we evaluate the evolution of the permeability field during the hydrothermal circulation. Our computations begin with a uniform permeability and a conductive thermal profile. After imposing a small random perturbation on the initial thermal field, the circulation adopts a finger-like structure, typical of convection in vertical porous slots thermally influenced by surrounding walls. Due to the strong temperature dependence of the fluid viscosity and thermal expansion, the hot rising fingers are strongly buoyant and collide with the top cold stagnant water layer. At the interface of the cold and hot layers, a horizontal boundary layer develops causing massive precipitation. This precipitation front produces a barrier to the hydrothermal flow. Consequently, the flow becomes layered on both sides of the front. The fluid temperature at the top of the layer remains quite low: it never exceeds a temperature of 80°C, well below the exit temperature of hot vent sites observed at

  4. Prediction of permeability changes in an excavation response zone

    International Nuclear Information System (INIS)

    Kinoshita, Naoto; Ishii, Takashi; Kuroda, Hidetaka; Tada, Hiroyuki

    1992-01-01

    In geologic disposal of radioactive wastes, stress changes due to cavern excavation may expand the existing fractures and create possible bypasses for groundwater. This paper proposes a simple method for predicting permeability changes in the excavation response zones. Numerical analyses using this method predict that the response zones created by cavern excavation would differ greatly in thickness and permeability depending on the depth of the cavern site and the initial in-situ stress, that when the cavern site is deeper, response zones would expand more and permeability would increases more, and that if the ratio of horizontal to vertical in-situ stress is small, extensive permeable zones at the crown and the bottom would occur, whereas if the ratio is large, extensive permeable zones would occur in the side walls. (orig.)

  5. The Effect of Excipients on the Permeability of BCS Class III Compounds and Implications for Biowaivers.

    Science.gov (United States)

    Parr, Alan; Hidalgo, Ismael J; Bode, Chris; Brown, William; Yazdanian, Mehran; Gonzalez, Mario A; Sagawa, Kazuko; Miller, Kevin; Jiang, Wenlei; Stippler, Erika S

    2016-01-01

    Currently, the FDA allows biowaivers for Class I (high solubility and high permeability) and Class III (high solubility and low permeability) compounds of the Biopharmaceutics Classification System (BCS). Scientific evidence should be provided to support biowaivers for BCS Class I and Class III (high solubility and low permeability) compounds. Data on the effects of excipients on drug permeability are needed to demonstrate that commonly used excipients do not affect the permeability of BCS Class III compounds, which would support the application of biowaivers to Class III compounds. This study was designed to generate such data by assessing the permeability of four BCS Class III compounds and one Class I compound in the presence and absence of five commonly used excipients. The permeability of each of the compounds was assessed, at three to five concentrations, with each excipient in two different models: Caco-2 cell monolayers, and in situ rat intestinal perfusion. No substantial increases in the permeability of any of the compounds were observed in the presence of any of the tested excipients in either of the models, with the exception of disruption of Caco-2 cell monolayer integrity by sodium lauryl sulfate at 0.1 mg/ml and higher. The results suggest that the absorption of these four BCS Class III compounds would not be greatly affected by the tested excipients. This may have implications in supporting biowaivers for BCS Class III compounds in general.

  6. Changes in permeability caused by transient stresses: field observations, experiments, and mechanisms

    Science.gov (United States)

    Manga, Michael; Beresnev, Igor; Brodsky, Emily E.; Elkhoury, Jean E.; Elsworth, Derek; Ingebritsen, Steve E.; Mays, David C.; Wang, Chi-Yuen

    2012-01-01

    Oscillations in stress, such as those created by earthquakes, can increase permeability and fluid mobility in geologic media. In natural systems, strain amplitudes as small as 10–6 can increase discharge in streams and springs, change the water level in wells, and enhance production from petroleum reservoirs. Enhanced permeability typically recovers to prestimulated values over a period of months to years. Mechanisms that can change permeability at such small stresses include unblocking pores, either by breaking up permeability-limiting colloidal deposits or by mobilizing droplets and bubbles trapped in pores by capillary forces. The recovery time over which permeability returns to the prestimulated value is governed by the time to reblock pores, or for geochemical processes to seal pores. Monitoring permeability in geothermal systems where there is abundant seismicity, and the response of flow to local and regional earthquakes, would help test some of the proposed mechanisms and identify controls on permeability and its evolution.

  7. Damage-induced permeability changes around underground excavations

    International Nuclear Information System (INIS)

    Coll, C.

    2005-07-01

    The storage of nuclear waste in deep geological formations is now considered more and more as a potential solution. During excavation, a disturbed zone develops in which damaging can be important and which can lead eventually to the failure of the rock. Fluid flow and permeability in the rock mass can be significantly modified producing a possible security risk. Our work consisted in an experimental study of the hydro-mechanical coupling of two argillaceous rocks: Boom clay (Mol, Belgium) and Opalinus clay (Mont-Terri, Switzerland). Triaxial tests were performed in a saturated state to study the permeability evolution of both clays with isotropic and deviatoric stresses. Argillaceous rocks are geo-materials with complex behaviour governed by numerous coupled processes. Strong physico-chemical interactions between the fluid and the solid particles and their very low permeability required the modification of the experimental set up. Moreover, specific procedures were developed to measure permeability and to detect strain localisation in shear bands. We show that for Boom Clay, permeability is not significantly influenced by strain localisation. For Opalinus clay, fracturing can induce an increase of the permeability at low confining pressure. (author)

  8. Modeling stress/strain-dependent permeability changes for deep geoenergy applications

    Science.gov (United States)

    Rinaldi, Antonio Pio; Rutqvist, Jonny

    2016-04-01

    Rock permeability is a key parameter in deep geoenergy systems. Stress and strain changes induced at depth by fluid injection or extraction may substantially alter the rock permeability in an irreversible way. With regard to the geoenergies, some applications require the permeability to be enhanced to improve productivity. The rock permeability is generally enhanced by shearing process of faults and fractures (e.g. hydroshearing for Enhanced and Deep Geothermal Systems), or the creation of new fractures (e.g. hydrofracturing for shale gas). However, such processes may, at the same time, produce seismicity that can be felt by the local population. Moreover, the increased permeability due to fault reactivation may pose at risk the sealing capacity of a storage site (e.g. carbon sequestration or nuclear waste disposal), providing then a preferential pathway for the stored fluids to escape at shallow depth. In this work we present a review of some recent applications aimed at understanding the coupling between stress (or strain) and permeability. Examples of geoenergy applications include both EGS and CO2 sequestration. To investigate both "wanted" and "unwanted" effects, THM simulations have been carried out with the TOUGH-FLAC simulator. Our studies include constitutive equations relating the permeability to mean effective stress, effective normal stress, volumetric strain, as well as accounting for permeability variation as related to fault/fracture reactivation. Results show that the geomechanical effects have a large role in changing the permeability, hence affecting fluids leakage, reservoir enhancement, as well as the induced seismicity.

  9. Changes in coal permeability in the process of deformation

    Czech Academy of Sciences Publication Activity Database

    Kožušníková, Alena

    2001-01-01

    Roč. 45, 2-4 (2001), s. 75-77 ISSN 0001-7132. [ Coal Geology Conference /9./. Praha, 25.06.2001-29.06.2001] R&D Projects: GA ČR GA105/00/0875 Institutional research plan: CEZ:AV0Z3086906 Keywords : gas permeability measurement * triaxial state of stress Subject RIV: DB - Geology ; Mineralogy

  10. Bronchoalveolar permeability changes in rats inhaling gas/particle combinations during rest or exercise

    International Nuclear Information System (INIS)

    Bhalla, D.K.; Phalen, R.F.; Mannix, R.C.; Lavan, S.M.; Crocker, T.T.

    1986-01-01

    Bronchoalveolar (BA) injury in rats exposed at rest or exercise to air pollutants was studied by changes in epithelial permeability. Rats exposed to air, single gases or pollutant combinations were anesthetized, tracheostomized, and placed on an incline. /sup 99m/Tc-DTPA was delivered directly to a major bronchus. Radioactivity measurements were made on blood samples collected during first 10 min. Exposure of resting rats to 0.6 ppm O 3 increased BA permeability just after exposure, but it was normal 24 hrs later; in exercising rats the increase was greater than in rats exposed at rest, and it persisted up to 24 hrs. NO 2 at 6 ppm did not affect permeability. Exposure of resting rats to 2.5 ppm NO 2 + 0.6 ppm O 3 only increased permeability right after the exposure, but in exercising rats this exposure resulted in a greater permeability which remained elevated up to 24 hrs. Exposure of exercising rats to 0.8 ppm O 3 + 10 ppm HCHO increased permeability. Exposure of resting rats to an atmosphere of 0.6 ppm O 3 + 2.5 ppm NO 2 + 5 ppm SO 2 + 1 mg/m 3 sulfates of ferric, ammonium and manganese also produced an increase in permeability that persisted up to 24 hrs. The results suggest potentiation of the pollutant effects by exercise, but there is no indication of synergistic effect of pollutant combinations on BA permeability

  11. Changes in sapwood permeability and anatomy with tree age and height in the broad-leaved evergreen species Eucalyptus regnans.

    Science.gov (United States)

    England, Jacqueline R; Attiwill, Peter M

    2007-08-01

    Increases in plant size and structural complexity with increasing age have important implications for water flow through trees. Water supply to the crown is influenced by both the cross-sectional area and the permeability of sapwood. It has been hypothesized that hydraulic conductivity within sapwood increases with age. We investigated changes in sapwood permeability (k) and anatomy with tree age and height in the broad-leaved evergreen species Eucalyptus regnans F. Muell. Sapwood was sampled at breast height from trees ranging from 8 to 240 years old, and at three height positions on the main stem of 8-year-old trees. Variation in k was not significant among sampling height positions in young trees. However, k at breast height increased with tree age. This was related to increases in both vessel frequency and vessel diameter, resulting in a greater proportion of sapwood being occupied by vessel lumina. Sapwood hydraulic conductivity (the product of k and sapwood area) also increased with increasing tree age. However, at the stand level, there was a decrease in forest sapwood hydraulic conductivity with increasing stand age, because of a decrease in the number of trees per hectare. Across all ages, there were significant relationships between k and anatomy, with individual anatomical characteristics explaining 33-62% of the variation in k. There was also strong agreement between measured k and permeability predicted by the Hagen-Poiseuille equation. The results support the hypothesis of an increase in sapwood permeability at breast height with age. Further measurements are required to confirm this result at other height positions in older trees. The significance of tree-level changes in sapwood permeability for stand-level water relations is discussed.

  12. Permeability changes in coal resulting from gas desorption. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Levine, J.R.; Johnson, P.W.

    1992-11-30

    This report documents studies on the effects of gas sorption on coal, with the intent of eventually evaluating how sorption and strain affect permeability. These studies were, carried out at the University of Alabama during the period from 1989 through 1992. Two major experimental methods were developed and used. In the strain experiments, electronic strain gauges were attached to polished blocks of coal in order to measure linear and volumetric swelling due to gas sorption. The effects of bedding plane orientation, of gas type, and of coal type were investigated. In the gravimetric experiment the weight of small samples of coal was measured during exposure to high pressure gases. Sample measurements were corrected for buoyancy effects and for sample swelling, and the results were plotted in the form of Langmuir isotherms. Experiments were conducted to determine the effect of grain size, coal type, moisture, and of sorbant gas. The advantage of this method is that it can be applied to very small samples, and it enabled comparison liptinite versus vitrinite concentrates, and kerogen rich versus kerogen depleted oil shales. Also included is a detailed discussion of the makeup of coal and its effect on gas sorption behavior.

  13. Permeability changes in coal resulting from gas desorption

    Energy Technology Data Exchange (ETDEWEB)

    Levine, J.R.; Johnson, P.W.

    1992-11-30

    This report documents studies on the effects of gas sorption on coal, with the intent of eventually evaluating how sorption and strain affect permeability. These studies were, carried out at the University of Alabama during the period from 1989 through 1992. Two major experimental methods were developed and used. In the strain experiments, electronic strain gauges were attached to polished blocks of coal in order to measure linear and volumetric swelling due to gas sorption. The effects of bedding plane orientation, of gas type, and of coal type were investigated. In the gravimetric experiment the weight of small samples of coal was measured during exposure to high pressure gases. Sample measurements were corrected for buoyancy effects and for sample swelling, and the results were plotted in the form of Langmuir isotherms. Experiments were conducted to determine the effect of grain size, coal type, moisture, and of sorbant gas. The advantage of this method is that it can be applied to very small samples, and it enabled comparison liptinite versus vitrinite concentrates, and kerogen rich versus kerogen depleted oil shales. Also included is a detailed discussion of the makeup of coal and its effect on gas sorption behavior.

  14. Intestinal permeability and its regulation by zonulin: diagnostic and therapeutic implications.

    Science.gov (United States)

    Fasano, Alessio

    2012-10-01

    One of the most important and overlooked functions of the gastrointestinal tract is to provide a dynamic barrier to tightly controlled antigen trafficking through both the transcellular and paracellular pathways. Intercellular tight junctions (TJ) are the key structures regulating paracellular trafficking of macromolecules. Although steady progress has been made in understanding TJ ultrastructure, relatively little is known about their pathophysiological regulation. Our discovery of zonulin, the only known physiological modulator of intercellular TJ described so far, increased understanding of the intricate mechanisms that regulate gut permeability and led us to appreciate that its up-regulation in genetically susceptible individuals may lead to immune-mediated diseases. This information has translational implications, because the zonulin pathway is currently exploited to develop both diagnostic and therapeutic applications pertinent to a variety of immune-mediated diseases. Copyright © 2012 AGA Institute. Published by Elsevier Inc. All rights reserved.

  15. Double porosity model to describe both permeability change and dissolution processes

    International Nuclear Information System (INIS)

    Niibori, Yuichi; Usui, Hideo; Chida, Taiji

    2015-01-01

    Cement is a practical material for constructing the geological disposal system of radioactive wastes. The dynamic behavior of both permeability change and dissolution process caused by a high pH groundwater was explained using a double porosity model assuming that each packed particle consists of the sphere-shaped aggregation of smaller particles. This model assumes two kinds of porosities between the particle clusters and between the particles, where the former porosity change mainly controls the permeability change of the bed, and the latter porosity change controls the diffusion of OH"- ions inducing the dissolution of silica. The fundamental equations consist of a diffusion equation of spherical coordinates of OH"- ions including the first-order reaction term and some equations describing the size changes of both the particles and the particle clusters with time. The change of over-all permeability of the packed bed is evaluated by Kozeny-Carman equation and the calculated radii of particle clusters. The calculated result well describes the experimental result of both permeability change and dissolution processes. (author)

  16. The Effect of Excipients on the Permeability of BCS Class III Compounds and Implications for Biowaivers

    OpenAIRE

    Parr, Alan; Hidalgo, Ismael J.; Bode, Chris; Brown, William; Yazdanian, Mehran; Gonzalez, Mario A.; Sagawa, Kazuko; Miller, Kevin; Jiang, Wenlei; Stippler, Erika S.

    2015-01-01

    Purpose Currently, the FDA allows biowaivers for Class I (high solubility and high permeability) and Class III (high solubility and low permeability) compounds of the Biopharmaceutics Classification System (BCS). Scientific evidence should be provided to support biowaivers for BCS Class I and Class III (high solubility and low permeability) compounds. Methods Data on the effects of excipients on drug permeability are needed to demonstrate that commonly used excipients do not affect the permea...

  17. Crustal permeability

    Science.gov (United States)

    Gleeson, Tom; Ingebritsen, Steven E.

    2016-01-01

    Permeability is the primary control on fluid flow in the Earth’s crust and is key to a surprisingly wide range of geological processes, because it controls the advection of heat and solutes and the generation of anomalous pore pressures.  The practical importance of permeability – and the potential for large, dynamic changes in permeability – is highlighted by ongoing issues associated with hydraulic fracturing for hydrocarbon production (“fracking”), enhanced geothermal systems, and geologic carbon sequestration.  Although there are thousands of research papers on crustal permeability, this is the first book-length treatment.  This book bridges the historical dichotomy between the hydrogeologic perspective of permeability as a static material property and the perspective of other Earth scientists who have long recognized permeability as a dynamic parameter that changes in response to tectonism, fluid production, and geochemical reactions. 

  18. Intestinal Permeability: The Basics

    Directory of Open Access Journals (Sweden)

    Ingvar Bjarnason

    1995-01-01

    Full Text Available The authors review some of the more fundamental principles underlying the noninvasive assessment of intestinal permeability in humans, the choice of test markers and their analyses, and the practical aspects of test dose composition and how these can be changed to allow the specific assessment of regional permeability changes and other intestinal functions. The implications of increased intestinal permeability in the pathogenesis of human disease is discussed in relation to findings in patients with Crohn’s disease. A common feature of increased intestinal permeability is the development of a low grade enteropathy, and while quantitatively similar changes may be found in Crohn’s disease these seem to predict relapse of disease. Moreover, factors associated with relapse of Crohn’s disease have in common an action to increase intestinal permeability. While increased intestinal permeability does not seem to be important in the etiology of Crohn’s disease it may be a central mechanism in the clinical relapse of disease.

  19. Modeling studies of unsaturated flow with long-term permeability change at Yucca Mountain

    International Nuclear Information System (INIS)

    Zhang Chengyuan; Liu Xiaoyan; Liu Quansheng

    2008-01-01

    The amount of water seeping into the waste emplacement drifts is crucial for the performance of underground nuclear waste repository, since it controls the corrosion rates of waste packages and the mobilization rate of radionuclides. It is limited by water flow through drift vicinity. In the present work we study the potential rates of water flow around drifts as a function of predicted long-term change of permeability at Yucca Mountain, based on a dual-continuum model of the unsaturated flow in fractured rock mass. For stage of DECOVALEX Ⅳ, we used a simplified practical model on unsaturated flow in Yucca Mountain case simulation. These models contain main physical processes that should be considered, including thermal expansion, thermal radiation, water-rock coupling and stress-induced change of permeability. Comparative study with other DECOVALEX team's results shows that they are both good enough and flexible enough to include more physical processes. We can draw the conclusion that it is necessary to model stress-induced changes in permeability and relative processes in future studies, because there are obvious differences (in water saturation and water flux) between simulation cases with and without variable permeability, especially in areas very close to the drift. (authors)

  20. Effect of gas type on foam film permeability and its implications for foam flow in porous media.

    Science.gov (United States)

    Farajzadeh, R; Muruganathan, R M; Rossen, W R; Krastev, R

    2011-10-14

    The aim of this paper is to provide a perspective on the effect of gas type on the permeability of foam films stabilized by different types of surfactant and to present a critical overview of the tracer gas experiments, which is the common approach to determine the trapped fraction of foam in porous media. In these experiments some part of the gas is replaced by a "tracer gas" during the steady-state stage of the experiments and trapped fraction of foam is determined by fitting the effluent data to a capacitance mass-transfer model. We present the experimental results on the measurement of the gas permeability of foam films stabilized with five surfactants (non-ionic, anionic and cationic) and different salt concentrations. The salt concentrations assure formation of either common black (CBF) or Newton black films (NBF). The experiments are performed with different single gasses. The permeability of the CBF is in general higher than that of the NBF. This behavior is explained by the higher density of the surfactant molecules in the NBF compared to that of CBF. It is also observed that the permeability coefficient, K(cm/s), of CBF and NBF for non-ionic and cationic surfactants are similar and K is insensitive to film thickness. Compared to anionic surfactants, the films made by the non-ionic surfactant have much lower permeability while the films made by the cationic surfactant have larger permeability. This conclusion is valid for all gasses. For all types of surfactant the gas permeability of foam film is largely dependent on the dissolution of gas in the surfactant solution and increases with increasing gas solubility in the bulk liquid. The measured values of K are consistent with rapid diffusion of tracer gasses through trapped gas adjacent to flowing gas in porous media, and difficulties in interpreting the results of tracer-foam experiments with conventional capacitance models. The implications of the results for foam flow in porous media and factors leading

  1. Front gardens to car parks: changes in garden permeability and effects on flood regulation.

    Science.gov (United States)

    Warhurst, Jennifer R; Parks, Katherine E; McCulloch, Lindsay; Hudson, Malcolm D

    2014-07-01

    This study addresses the consequences of widespread conversion of permeable front gardens to hard standing car parking surfaces, and the potential consequences in high-risk urban flooding hotspots, in the city of Southampton. The last two decades has seen a trend for domestic front gardens in urban areas to be converted for parking, driven by the lack of space and increased car ownership. Despite media and political attention, the effects of this change are unknown, but increased and more intense rainfall, potentially linked to climate change, could generate negative consequences as runoff from impermeable surfaces increases. Information is limited on garden permeability change, despite the consequences for ecosystem services, especially flood regulation. We focused on eight flooding hotspots identified by the local council as part of a wider urban flooding policy response. Aerial photographs from 1991, 2004 and 2011 were used to estimate changes in surface cover and to analyse permeability change within a digital surface model in a GIS environment. The 1, 30 and 100 year required attenuation storage volumes were estimated, which are the temporary storage required to reduce the peak flow rate given surface permeability. Within our study areas, impermeable cover in domestic front gardens increased by 22.47% over the 20-year study period (1991-2011) and required attenuation storage volumes increased by 26.23% on average. These increases suggest that a consequence of the conversion of gardens to parking areas will be a potential increase in flooding frequency and severity - a situation which is likely to occur in urban locations worldwide. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. Heat stress, gastrointestinal permeability and interleukin-6 signaling - Implications for exercise performance and fatigue.

    Science.gov (United States)

    Vargas, Nicole; Marino, Frank

    2016-01-01

    Exercise in heat stress exacerbates performance decrements compared to normothermic environments. It has been documented that the performance decrements are associated with reduced efferent drive from the central nervous system (CNS), however, specific factors that contribute to the decrements are not completely understood. During exertional heat stress, blood flow is preferentially distributed away from the intestinal area to supply the muscles and brain with oxygen. Consequently, the gastrointestinal barrier becomes increasingly permeable, resulting in the release of lipopolysaccharides (LPS, endotoxin) into the circulation. LPS leakage stimulates an acute-phase inflammatory response, including the release of interleukin (IL)-6 in response to an increasingly endotoxic environment. If LPS translocation is too great, heat shock, neurological dysfunction, or death may ensue. IL-6 acts initially in a pro-inflammatory manner during endotoxemia, but can attenuate the response through signaling the hypothalamic pituitary adrenal (HPA)-axis. Likewise, IL-6 is believed to be a thermoregulatory sensor in the gut during the febrile response, hence highlighting its role in periphery - to - brain communication. Recently, IL-6 has been implicated in signaling the CNS and influencing perceptions of fatigue and performance during exercise. Therefore, due to the cascade of events that occur during exertional heat stress, it is possible that the release of LPS and exacerbated response of IL-6 contributes to CNS modulation during exertional heat stress. The purpose of this review is to evaluate previous literature and discuss the potential role for IL-6 during exertional heat stress to modulate performance in favor of whole body preservation.

  3. In situ measurements of rock salt permeability changes due to nearby excavation

    International Nuclear Information System (INIS)

    Stormont, J.C.; Howard, C.L.; Daemen, J.J.K.

    1991-07-01

    The Small-Scale Mine-By was an in situ experiment to measure changes in brine and gas permeability of rock salt as a result of nearby excavation. A series of small-volume pressurized brine- and gas-filled test intervals were established 8 m beneath the floor of Room L1 in the WIPP underground. The test intervals were isolated in the bottom of the 4.8-cm diameter monitoring boreholes with inflatable rubber packers, and are initially pressurized to about 2 MPa. Both brine- and gas-filled test intervals were located 1.25, 1.5, 2, 3, and 4 r from the center of a planned large-diameter hole, where r is the radius of the large-diameter hole. Prior to the drilling of the large-diameter borehole, the responses of both the brine- and gas-filled test intervals were consistent with the formation modeled as a very low permeability, low porosity porous medium with a significant pore (brine) pressure and no measurable gas permeability. The drilling of the mine-by borehole created a zone of dilated, partially saturated rock out to about 1.5 r. The formation pressure increases from near zero at 1.5 r to the pre-excavation value at 4 r. Injection tests reveal a gradient of brine permeabilities from 5 x 10 -18 m 2 at 1.25 r to about the pre-excavation value (10 -21 m 2 ) by 3 r. Gas-injection tests reveal measurable gas permeability is limited to within 1.5 r. 17 refs., 24 figs., 6 tabs

  4. Coupled Analysis of Change in Fracture Permeability during the Cooling Phase of the Yucca Mountain Drift Scale Test

    International Nuclear Information System (INIS)

    Rutqvist, Jonny; Rutqvist, J.; Freifeld, B.; Tsang, Y.W.; Min, K.B.; Elsworth, D.

    2008-01-01

    This paper presents results from a coupled thermal, hydrological and mechanical analysis of thermally-induced permeability changes during heating and cooling of fractured volcanic rock at the Drift Scale Test at Yucca Mountain, Nevada. The analysis extends the previous analysis of the four-year heating phase to include newly available data from the subsequent four year cooling phase. The new analysis of the cooling phase shows that the measured changes in fracture permeability follows that of a thermo-hydro-elastic model on average, but at several locations the measured permeability indicates (inelastic) irreversible behavior. At the end of the cooling phase, the air-permeability had decreased at some locations (to as low as 0.2 of initial), whereas it had increased at other locations (to as high as 1.8 of initial). Our analysis shows that such irreversible changes in fracture permeability are consistent with either inelastic fracture shear dilation (where permeability increased) or inelastic fracture surface asperity shortening (where permeability decreased). These data are important for bounding model predictions of potential thermally-induced changes in rock-mass permeability at a future repository at Yucca Mountain

  5. Permeability and microstructural changes due to weathering of pyroclastic rocks in Cappadocia, central Turkey

    Science.gov (United States)

    Sato, M.; Takahashi, M.; Anma, R.; Shiomi, K.

    2014-12-01

    Studies of permeability changes of rocks during weathering are important to understand the processes of geomorphological development and how they are influenced by cyclic climatic conditions. Especially volcanic tuffs and pyroclastic flow deposits are easily affected by water absorption and freezing-thawing cycle (Erguler. 2009, Çelik and Ergül 2014). Peculiar erosional landscapes of Cappadocia, central Turkey, with numerous underground cities and carved churches, that made this area a world heritage site, are consists of volcanic tuffs and pyroclastic flow deposits. Understanding permeability changes of such rocks under different conditions are thus important not only to understand fundamental processes of weathering, but also to protect the landscapes of the world heritage sites and archaeological remains. In this study, we aim to evaluate internal void structures and bulk permeability of intact and weathered pyroclastic rocks from Cappadocia using X-ray CT, mercury intrusion porosimetry data and permeability measurement method of flow pump test. Samples of pyroclastic deposits that comprise the landscapes of Rose Valley and Ihlara Valley, were collected from the corresponding strata outside of the preservation areas. Porosity and pore-size distribution for the same samples measured by mercury intrusion porosimetry, indicate that the intact samples have lower porosity than weathered samples and pore sizes were dominantly 1-10μm in calculated radii, whereas weathered samples have more micropores (smaller than 1 μm). X-ray CT images were acquired to observe internal structure of samples. Micro-fractures, probably caused by repeated expansion and contraction due to temperature changes, were observed around clast grains. The higher micropore ratio in weathered samples could be attributed to the development of the micro-farctures. We will discuss fundamental processes of weathering and geomorphological development models using these data.

  6. Strength and Permeability Evolution of Compressed Bentonite in Response to Salinity and Temperature Changes

    Science.gov (United States)

    Winnard, B. R.; Mitchell, T. M.; Browning, J.; Cuss, R. J.; Norris, S.; Meredith, P. G.

    2017-12-01

    Deep geological repositories are the preferred solution to dispose of radioactive waste; design concepts for these disposal facilities include compacted, saturated bentonite as a buffer between waste canister and host rock. Bentonite is favoured for its high swelling capacity, low permeability, and radionuclide retention properties. However, its thermo-hydro-mechanical tolerances must be thoroughly tested to ensure adequate long term performance. Climate variations are likely to induce periods of permafrost, and consequently, changes in groundwater salinity at depth. We performed laboratory experiments investigating effects of temperature and salinity change on uniaxial compressive strength (UCS), and permeability of compacted MX-80 bentonite cylinders. These specimens (moisture content = 22.9±0.1%, dry density = 1.66±0.02 g.cm-3) were compacted with deionised water, and a range of wt% NaCl, CaCl2, or KCl, to compare the effects of compaction fluid. Samples of compressed bentonite were cooled to -20 °C, and heated to 90 ºC, a possible temperature forecast for a repository dependent on factors such as geographical location, waste type, and facility design. Tests were all performed at room temperature, however in situ temperature tests are planned. The UCS of samples that experienced freeze thaw, and 40 ºC treatment failed at 6.5 MPa, with 4% strain, maintaining the same values as untreated bentonite compacted with deionised water. Samples compacted with saline solutions also yielded similar strengths, of 7 MPa, and failed at 4%. However, the 90 ºC, regardless of compaction fluid, failed at 15-18 MPa, at just 2% strain. In all experiments, the spread of strain accommodated varied inconsistently, however, peak stress was uniform. Further experiments into heterogeneity are needed to understand the responsible mechanisms. To obtain permeability, we utilised the pore pressure oscillation (PPO) technique with argon as the pore fluid. We also tested water as the pore

  7. Phasic changes of blood-brain-barrier permeability in mice after non-uniform γ-irradiation

    International Nuclear Information System (INIS)

    Ushakov, I.B.

    1986-01-01

    Early changes of blood-brain barrier (BBB) permeability in mice after irradiation of head or body were studied. The experiments were carried out on male-mice F 1 (C57xCBA) with medium mass of 25.1±0.8 g, irradiated in 2.58 C/kg dose to head or body. Correlation between BBB permeability decrease and radiation disease clinical manifestation frequency is determined. In early periods after irradiation, minimum two phases of BBB permeability change were observed: increase (0-2 h) and decrease (2-6 h) of permeability. BBB changes were expressed in later periods (24-120 h) as well. BBB permeability progressively increased after irradiation of head. According to the author's suggestion, this phenomenon gives evidence of generalization of vessel permeability disturbance (primarily of brain vessels) which leads to complete BBB dysfunction and to the loss of this morphofunctional formation's ability to perform its protective function. When considering BBB permeability connection with the frequency of neurologycal sign (tremor, ataxia) appearance, reversible correlation between these indicators is marked, beginning with the first period. The presence connection of fluid redistribution between blood and internal brain medium (edema growth) with the development of clinical manifestations of CNS affection is suggested

  8. Elastic-Brittle-Plastic Behaviour of Shale Reservoirs and Its Implications on Fracture Permeability Variation: An Analytical Approach

    Science.gov (United States)

    Masoudian, Mohsen S.; Hashemi, Mir Amid; Tasalloti, Ali; Marshall, Alec M.

    2018-05-01

    Shale gas has recently gained significant attention as one of the most important unconventional gas resources. Shales are fine-grained rocks formed from the compaction of silt- and clay-sized particles and are characterised by their fissured texture and very low permeability. Gas exists in an adsorbed state on the surface of the organic content of the rock and is freely available within the primary and secondary porosity. Geomechanical studies have indicated that, depending on the clay content of the rock, shales can exhibit a brittle failure mechanism. Brittle failure leads to the reduced strength of the plastic zone around a wellbore, which can potentially result in wellbore instability problems. Desorption of gas during production can cause shrinkage of the organic content of the rock. This becomes more important when considering the use of shales for CO2 sequestration purposes, where CO2 adsorption-induced swelling can play an important role. These phenomena lead to changes in the stress state within the rock mass, which then influence the permeability of the reservoir. Thus, rigorous simulation of material failure within coupled hydro-mechanical analyses is needed to achieve a more systematic and accurate representation of the wellbore. Despite numerous modelling efforts related to permeability, an adequate representation of the geomechanical behaviour of shale and its impact on permeability and gas production has not been achieved. In order to achieve this aim, novel coupled poro-elastoplastic analytical solutions are developed in this paper which take into account the sorption-induced swelling and the brittle failure mechanism. These models employ linear elasticity and a Mohr-Coulomb failure criterion in a plane-strain condition with boundary conditions corresponding to both open-hole and cased-hole completions. The post-failure brittle behaviour of the rock is defined using residual strength parameters and a non-associated flow rule. Swelling and shrinkage

  9. Grain-Size Dynamics Beneath Mid-Ocean Ridges: Implications for Permeability and Melt Extraction

    Science.gov (United States)

    Turner, A. J.; Katz, R. F.; Behn, M. D.

    2014-12-01

    The permeability structure of the sub-ridge mantle plays an important role in how melt is focused and extracted at mid-ocean ridges. Permeability is controlled by porosity and the grain size of the solid mantle matrix, which is in turn controlled by the deformation conditions. To date, models of grain size evolution and mantle deformation have not been coupled to determine the influence of spatial variations in grain-size on the permeability structure at mid-ocean ridges. Rather, current models typically assume a constant grain size for the whole domain [1]. Here, we use 2-D numerical models to evaluate the influence of grain-size variability on the permeability structure beneath a mid-ocean ridge and use these results to speculate on the consequences for melt focusing and extraction. We construct a two-dimensional, single phase model for the steady-state grain size beneath a mid-ocean ridge. The model employs a composite rheology of diffusion creep, dislocation creep, dislocation accommodated grain boundary sliding, and a brittle stress limiter. Grain size is calculated using the "wattmeter" model of Austin and Evans [2]. We investigate the sensitivity of the model to global variations in grain growth exponent, potential temperature, spreading-rate, and grain boundary sliding parameters [3,4]. Our model predicts that permeability varies by two orders of magnitude due to the spatial variability of grain size within the expected melt region of a mid-ocean ridge. The predicted permeability structure suggests grain size may promote focusing of melt towards the ridge axis. Furthermore, the calculated grain size structure should focus melt from a greater depth than models that exclude grain-size variability. Future work will involve evaluating this hypothesis by implementing grain-size dynamics within a two-phase mid-ocean ridge model. The developments of such a model will be discussed. References: [1] R. F. Katz, Journal of Petrology, volume 49, issue 12, page 2099

  10. Climate Change Communication Research: Trends and Implications ...

    African Journals Online (AJOL)

    Climate Change Communication Research: Trends and Implications. ... African Journal of Sustainable Development ... with a specific focus on the themes that have dominated current studies, major research methods in use, major theories that ...

  11. Changing business environment: implications for farming

    OpenAIRE

    Malcolm, Bill

    2011-01-01

    The natural, technological, economic, political and social environment in which farmers farm constantly changes. History has lessons about change in agriculture and about farmers coping with change, though the future is unknowable and thus always surprising. The implication for farm operation is to prepare, do not predict.

  12. Permeability Changes Observed in the Arbuckle Group Coincident with Nearby Earthquake Occurrence

    Science.gov (United States)

    Kroll, K.; Cochran, E. S.; Richards-Dinger, K. B.; Murray, K.

    2017-12-01

    We investigate the temporal evolution of hydrologic properties of the 2 km deep Arbuckle Group, the principal target in Oklahoma for saltwater disposal resulting from oil and gas production. Specifically, we look for changes to the hydrologic system associated with local earthquakes at two monitoring wells (Payne07 and 08) near Cushing, Oklahoma. The wells were instrumented with pressure transducers starting in Aug. 2016, after injection was discontinued due to regulatory directives. The observation period includes the 3 Sep 2016 Mw5.8 Pawnee and 7 Nov. 2016 Mw5.0 Cushing earthquakes located 50 km and 5 km from the wells, respectively. Previous studies have suggested the Mw5.8 Pawnee earthquake affected both the shallow and deep hydrological systems, with an increase in stream discharge observed near the mainshock (Manga et al., 2016) and a change in poroelastic properties of the Arbuckle inferred from the observed co-seismic water level offsets observed at Payne 07 and 08 (Kroll et al., 2017). Here, we use the water level response to solid Earth tides to estimate permeability and specific storage through time during the observation period. We measure the phase lag between the solid Earth tide and the water level changes and find that phase lag between the Earth tide and aquifer response decreases at the time of the Mw5.0 Cushing earthquake in both wells. Our results suggest permeability increased in the Arbuckle Group after the earthquake by a factor of 5. It is possible that in extreme cases there may be complex interaction between saltwater disposal, hydrologic systems, and earthquake rates that should be considered to better understand seismic hazard.

  13. Modeling of damage, permeability changes and pressure responses during excavation of the TSX tunnel in granitic rock at URL, Canada

    Science.gov (United States)

    Rutqvist, Jonny; Börgesson, Lennart; Chijimatsu, Masakazu; Hernelind, Jan; Jing, Lanru; Kobayashi, Akira; Nguyen, Son

    2009-05-01

    This paper presents numerical modeling of excavation-induced damage, permeability changes, and fluid-pressure responses during excavation of a test tunnel associated with the tunnel sealing experiment (TSX) at the Underground Research Laboratory (URL) in Canada. Four different numerical models were applied using a wide range of approaches to model damage and permeability changes in the excavation disturbed zone (EDZ) around the tunnel. Using in situ calibration of model parameters, the modeling could reproduce observed spatial distribution of damage and permeability changes around the tunnel as a combination of disturbance induced by stress redistribution around the tunnel and by the drill-and-blast operation. The modeling showed that stress-induced permeability increase above the tunnel is a result of micro and macrofracturing under high deviatoric (shear) stress, whereas permeability increase alongside the tunnel is a result of opening of existing microfractures under decreased mean stress. The remaining observed fracturing and permeability changes around the periphery of the tunnel were attributed to damage from the drill-and-blast operation. Moreover, a reasonably good agreement was achieved between simulated and observed excavation-induced pressure responses around the TSX tunnel for 1 year following its excavation. The simulations showed that these pressure responses are caused by poroelastic effects as a result of increasing or decreasing mean stress, with corresponding contraction or expansion of the pore volume. The simulation results for pressure evolution were consistent with previous studies, indicating that the observed pressure responses could be captured in a Biot model using a relatively low Biot-Willis’ coefficient, α ≈ 0.2, a porosity of n ≈ 0.007, and a relatively low permeability of k ≈ 2 × 10-22 m2, which is consistent with the very tight, unfractured granite at the site.

  14. Morphine induces expression of platelet-derived growth factor in human brain microvascular endothelial cells: implication for vascular permeability.

    Directory of Open Access Journals (Sweden)

    Hongxiu Wen

    Full Text Available Despite the advent of antiretroviral therapy, complications of HIV-1 infection with concurrent drug abuse are an emerging problem. Morphine, often abused by HIV-infected patients, is known to accelerate neuroinflammation associated with HIV-1 infection. Detailed molecular mechanisms of morphine action however, remain poorly understood. Platelet-derived growth factor (PDGF has been implicated in a number of pathological conditions, primarily due to its potent mitogenic and permeability effects. Whether morphine exposure results in enhanced vascular permeability in brain endothelial cells, likely via induction of PDGF, remains to be established. In the present study, we demonstrated morphine-mediated induction of PDGF-BB in human brain microvascular endothelial cells, an effect that was abrogated by the opioid receptor antagonist-naltrexone. Pharmacological blockade (cell signaling and loss-of-function (Egr-1 approaches demonstrated the role of mitogen-activated protein kinases (MAPKs, PI3K/Akt and the downstream transcription factor Egr-1 respectively, in morphine-mediated induction of PDGF-BB. Functional significance of increased PDGF-BB manifested as increased breach of the endothelial barrier as evidenced by decreased expression of the tight junction protein ZO-1 in an in vitro model system. Understanding the regulation of PDGF expression may provide insights into the development of potential therapeutic targets for intervention of morphine-mediated neuroinflammation.

  15. Radiation-induced changes in the profile of spinal cord serotonin, prostaglandin synthesis, and vascular permeability

    International Nuclear Information System (INIS)

    Siegal, Tali; Pfeffer, M. Raphael

    1995-01-01

    Purpose: To investigate the profile of biochemical and physiological changes induced in the rat spinal cord by radiation, over a period of 8 months. Methods and Materials: The thoraco-lumbar spinal cords of Fisher rats were irradiated to a dose of 15 Gy. The rats were then followed and killed at various times afterward. Serotonin (5-HT) and its major metabolite 5-hydroxyindole-3-acetic acid (5-HIAA) were assayed as well as prostaglandin synthesis. Microvessel permeability was assessed by quantitative evaluation of Evans blue dye extravasation. Results: None of the rats developed neurologic dysfunction, and histologic examination revealed only occasional gliosis in the ventral white matter at 240 days after irradiation. Serotonin levels were unchanged at 2, 14, and 56 days after radiation but increased at 120 and 240 days in the irradiated cord segments when compared to both the nonirradiated thoracic and cervical segments (p 2 (PGE 2 ), thromboxane (TXB 2 ), and prostacyclin [6 keto-PGF1α (6KPGF)] was noted, which returned to normal at 3 days. This was followed after 7 and 14 days by a significant fall off in synthesis of all three prostaglandins. Thereafter, at 28, 56, 120, and 240 days, escalated production of thromboxane followed, while prostacyclin synthesis remained markedly reduced (-88% of control level at 240 days). Up to 7 days after radiation the calculated (TXB 2 (6KPGF)) ratio remained balanced, regardless of the observed abrupt early fluctuations in their rate of synthesis. Later, between 7 and 240 days after radiation, a significant imbalance was present which became more pronounced over time. In the first 24 h after radiation, a 104% increase in microvessel permeability was observed which returned to normal by 3 days. Normal permeability was maintained at 14 and 28 days, but at 120 and 240 days a persistent and significant increase of 98% and 73% respectively above control level was noted. Conclusions: Radiation induces severe impairment in

  16. Radiation-induced changes in the profile of spinal cord serotonin, prostaglandin synthesis, and vascular permeability

    International Nuclear Information System (INIS)

    Siegal, T.; Pfeffer, M.R.

    1995-01-01

    To investigate the profile of biochemical and physiological changes induced in the rat spinal cord by radiation, over a period of 8 months. The thoraco-lumbar spinal cords of Fisher rats were irradiated to a dose of 15 Gy. The rats were then followed and killed at various times afterward. Serotonin (5-HT) and its major metabolite 5-hydroxyindole-3-acetic acid (5-HIAA) were assayed as well as prostaglandin synthesis. Microvessel permeability was assessed by quantitative evaluation of Evans blue dye extravasation. None of the rats developed neurologic dysfunction, and histologic examination revealed only occasional gliosis in the ventral white matter at 240 days after irradiation. Serotonin levels were unchanged at 2, 14, and 56 days after radiation but increased at 120 and 240 days in the irradiated cord segments when compared to both the nonirradiated thoracic and cervical segments (p 2 (PGE 2 ), thromboxane (TXB 2 ), and prostacyclin [6 keto-PGF1α (6KPGF)] was noted, which returned to normal at 3 days. This was followed after 7 and 14 days by a significant fall off in synthesis of all three prostaglandins. Thereafter, at 28, 56, 120, and 240 days, escalated production of thromboxane followed, white prostacyclin synthesis remained markedly reduced (-88% of control level at 240 days). Up to 7 days after radiation the calculated TXB 2 /6KPGF ratio remained balanced, regardless of the observed abrupt early fluctuations in their rate of synthesis. Later, between 7 and 240 days after radiation, a significant imbalance was present which became more pronounced over time. In the first 24 h after radiation, a 104% increase in microvessel permeability was observed which returned to normal by 3 days. 57 refs., 3 figs

  17. Dissociation of changes in the permeability of the blood-brain barrier from catecholamine-induced changes in blood pressure of normotensive and spontaneously hypertensive rats

    International Nuclear Information System (INIS)

    Sankar, R.; Domer, F.R.; Taylor, B.

    1982-01-01

    Researchers have studied the effects of the pressor catecholamine, dopamine, and the depressor catecholamine, isoproterenol, on the systemic blood pressure and the permeability of the blood-brain barrier (BBB) to albumin in normotensive (WKY) and spontaneously hypertensive (SHR) rats. The rats were anesthetized with pentobarbital. The permeability of the BBB to protein was measured by the extravasation of radioiodinated serum albumin (RISA). The permeability was decreased by both catecholamines despite the dose-dependent, yet opposite, changes in blood pressure in the WKY rats. The blood pressure response to both of the catecholamines was enhanced in the SHR rats. Isoproterenol caused a decrease in the permeability of the BBB in the SHR but dopamine did not. Results with both WKY and SHR rats are suggestive of an adrenergically-mediated decrease in movement across the BBB of compounds of large molecular weight, regardless of changes in blood pressure

  18. Changing Knowledge, Changing Technology: Implications for Teacher Education Futures

    Science.gov (United States)

    Burden, Kevin; Aubusson, Peter; Brindley, Sue; Schuck, Sandy

    2016-01-01

    Recent research in teacher education futures has identified two themes that require further study: the changing nature of knowledge and the changing capabilities of technologies. This article examines the intersection of these two themes and their implications for teacher education. The research employed futures methodologies based on scenario…

  19. Permeability enhancers dramatically increase zanamivir absolute bioavailability in rats: implications for an orally bioavailable influenza treatment.

    Directory of Open Access Journals (Sweden)

    Eric H Holmes

    Full Text Available We have demonstrated that simple formulations composed of the parent drug in combination with generally regarded as safe (GRAS permeability enhancers are capable of dramatically increasing the absolute bioavailability of zanamivir. This has the advantage of not requiring modification of the drug structure to promote absorption, thus reducing the regulatory challenges involved in conversion of an inhaled to oral route of administration of an approved drug. Absolute bioavailability increases of up to 24-fold were observed when Capmul MCM L8 (composed of mono- and diglycerides of caprylic/capric acids in glycerol was mixed with 1.5 mg of zanamivir and administered intraduodenally to rats. Rapid uptake (t(max of 5 min and a C(max of over 7200 ng/mL was achieved. Variation of the drug load or amount of enhancer demonstrated a generally linear variation in absorption, indicating an ability to optimize a formulation for a desired outcome such as a targeted C(max for enzyme saturation. No absorption enhancement was observed when the enhancer was given 2 hr prior to drug administration, indicating, in combination with the observed tmax, that absorption enhancement is temporary. This property is significant and aligns well with therapeutic applications to limit undesirable drug-drug interactions, potentially due to the presence of other poorly absorbed polar drugs. These results suggest that optimal human oral dosage forms of zanamivir should be enteric-coated gelcaps or softgels for intraduodenal release. There continues to be a strong need and market for multiple neuraminidase inhibitors for influenza treatment. Creation of orally available formulations of inhibitor drugs that are currently administered intravenously or by inhalation would provide a significant improvement in treatment of influenza. The very simple GRAS formulation components and anticipated dosage forms would require low manufacturing costs and yield enhanced convenience. These results

  20. Climate Change: Generic Implications for Agriculture

    Indian Academy of Sciences (India)

    Climate Change: Generic Implications for Agriculture. Increasing carbon dioxide: Good for most crops. Increase in mean temperature: orter ... Increasing rainfall intensity and dry days- more floods and droughts: Higher production variability. Himalayan glaciers to recede: irrigation in IGP gradually becomes less dependable ...

  1. Evaluation of blood--brain barrier permeability changes in rhesus monkeys and man using 82Rb and positron emission tomography

    International Nuclear Information System (INIS)

    Yen, C.K.; Budinger, T.F.

    1981-01-01

    Dynamic positron tomography of the brain with 82 Rb, obtained from a portable generator [ 82 Sr (25 days) -- 82 Rb (76 sec)], provides a means of studying blood-brain barrier (BBB) permeability in physiological and clinical investigations. The BBB in rhesus monkeys was opened unilaterally by intracarotid infusion of 3 M urea. This osmotic barrier opening allowed entry into the brain of intravenously administered rubidium chloride. The BBB opening was demonstrated noninvasively using 82 Rb and positron emission tomography and corroborated by the accumulation of 86 Rb in tissue samples. Positron emission tomography studies can be repeated every 5 min and indicate that dynamic tomography or static imaging can be used to study BBB permeability changes induced by a wide variety of noxious stimuli. Brain tumors in human subjects are readily detected because of the usual BBB permeability disruption in and around the tumors

  2. Identifying evidence of climate change impact on extreme events in permeable chalk catchments

    Science.gov (United States)

    Butler, A. P.; Nubert, S.

    2009-12-01

    The permeable chalk catchments of southern England are vital for the economy and well being of the UK. Not only important as a water resource, their freely draining soils support intensive agricultural production, and the rolling downs and chalk streams provide important habitants for many protected plant and animal species. Consequently, there are concerns about the potential impact of climate change on such catchments, particularly in relation to groundwater recharge. Of major concern are possible changes in extreme events, such as groundwater floods and droughts, as any increase in the frequency and/or severity of these has important consequences for water resources, ecological systems and local infrastructure. Studies of climate change impact on extreme events for such catchments have indicated that, under medium and high emissions scenarios, droughts are likely to become more severe whilst floods less so. However, given the uncertainties in such predictions and the inherent variability in historic data, producing definitive evidence of changes in flood/drought frequency/severity poses a significant challenge. Thus, there is a need for specific extreme event statistics that can be used as indicators of actual climate change in streamflow and groundwater level observations. Identifying such indicators that are sufficiently robust requires catchments with long historic time series data. One such catchment is the River Lavant, an intermittent chalk stream in West Sussex, UK. Located within this catchment is Chilgrove House, the site of the UK’s longest groundwater monitoring well (with a continuous record of water level observations of varying frequency dating back to 1836). Using a variety of meteorological datasets, the behaviour of the catchment has been modelled, from 1855 to present, using a 'leaky aquifer' conceptual model. Model calibration was based on observed daily streamflow, at a gauging station just outside the town of Chichester, from 1970. Long

  3. Changes in microvascular permeability of the middle ear mucosa following the occulsion of the eustachian tube of rabbits

    International Nuclear Information System (INIS)

    Kikuchi, Yasutaka

    1988-01-01

    Serial changes in submucosal microvascular permeability of the middle ear and the response to histamine after occlusion of the eustachian tube were functionally investigated using radioisotope in rabbits with experimentally induced otitis media with effusion. Tritium water was administered through intravenous injection and transference of tritium water into the middle ear cavity was measured by radioactivity of the middle ear perfusate. Morphological changes were concurrently examined for comparison. Vascular permeability, as measured one, 7, and 14 days after occlusion of the eustachian tube, increased with time. A histological study showed an edematous hypertrophy of the submucosal tissue of the middle ear, suggesting a noticeable increase in microvascular permeability. The response of the middle ear mucosa to histamine, which was added to the fluid for perfusion, gradually decreased after occlusion of the eustachian tube, although the effect of histamine tended to persist for a long time, irrespective of the amount of administration. The results indicated that the mucosal membrane of the middle ear has a noticeable permeability at least up to 14 days after occlusion, and that histamine may be responsible for the increase of submucosal microvascular permeability not only in the normal middle ear cavity but also in otitis media with effusion which results in the persistance of the disease. The presence of factors permeable to the blood, other than histamine, caused microvascular peameability to increase, probably resulting in chronic or irreversible inflammation. This may be explained by markedly proliferative or parenchymatous connective tissues observed 7 and l0 weeks after occlusion. It should be noted that surgical treatment be performed as early as possible in the case of otitis media with effusion. (Namekawa, K) 80 refs

  4. Relationship between changed alveolar-capillary permeability and angiotensin converting enzyme activity in serum in sarcoidosis.

    OpenAIRE

    Eklund, A; Blaschke, E

    1986-01-01

    The effect of altered alveolar-capillary permeability on angiotensin converting enzyme (ACE) activity in serum (SACE) was studied in 45 patients with sarcoidosis and 21 healthy controls. In sarcoidosis increased albumin concentrations in the bronchoalveolar lavage fluid (L albumin) and increased ratios of L albumin to albumin in serum (S albumin) indicated an increased permeability of the alveolar-capillary membrane. ACE activity in the lavage fluid (LACE) was correlated with the number of al...

  5. Climate Change and Interacting Stressors: Implications for ...

    Science.gov (United States)

    EPA announced the release of the final document, Climate Change and Interacting Stressors: Implications for Coral Reef Management in American Samoa. This report provides a synthesis of information on the interactive effects of climate change and other stressors on the reefs of American Samoa as well as an assessment of potential management responses. This report provides the coral reef managers of American Samoa, as well as other coral reef managers in the Pacific region, with some management options to help enhance the capacity of local coral reefs to resist the negative effects of climate change. This report was designed to take advantage of diverse research and monitoring efforts that are ongoing in American Samoa to: analyze and compile the results of multiple research projects that focus on understanding climate-related stressors and their effects on coral reef ecosystem degradation and recovery; and assess implications for coral reef managment of the combined information, including possible response options.

  6. The solubility-permeability interplay and its implications in formulation design and development for poorly soluble drugs.

    Science.gov (United States)

    Dahan, Arik; Miller, Jonathan M

    2012-06-01

    While each of the two key parameters of oral drug absorption, the solubility and the permeability, has been comprehensively studied separately, the relationship and interplay between the two have been largely ignored. For instance, when formulating a low-solubility drug using various solubilization techniques: what are we doing to the apparent permeability when we increase the solubility? Permeability is equal to the drug's diffusion coefficient through the membrane times the membrane/aqueous partition coefficient divided by the membrane thickness. The direct correlation between the intestinal permeability and the membrane/aqueous partitioning, which in turn is dependent on the drug's apparent solubility in the GI milieu, suggests that the solubility and the permeability are closely associated, exhibiting a certain interplay between them, and the current view of treating the one irrespectively of the other may not be sufficient. In this paper, we describe the research that has been done thus far, and present new data, to shed light on this solubility-permeability interplay. It has been shown that decreased apparent permeability accompanies the solubility increase when using different solubilization methods. Overall, the weight of the evidence indicates that the solubility-permeability interplay cannot be ignored when using solubility-enabling formulations; looking solely at the solubility enhancement that the formulation enables may be misleading with regards to predicting the resulting absorption, and hence, the solubility-permeability interplay must be taken into account to strike the optimal solubility-permeability balance, in order to maximize the overall absorption.

  7. Permeability changes induced by microfissure closure and opening in tectonized materials. Effect on slope pore pressure regime.

    Science.gov (United States)

    De la Fuente, Maria; Vaunat, Jean; Pedone, Giuseppe; Cotecchia, Federica; Sollecito, Francesca; Casini, Francesca

    2015-04-01

    Tectonized clays are complex materials characterized by several levels of structures that may evolve during load and wetting/drying processes. Some microstructural patterns, as microfissures, have a particular influence on the value of permeability which is one of the main factors controlling pore pressure regime in slopes. In this work, the pore pressure regime measured in a real slope of tectonized clay in Southern Italy is analyzed by a numerical model that considers changes in permeability induced by microfissure closure and opening during the wetting and drying processes resulting from climatic actions. Permeability model accounts for the changes in Pore Size Distribution observed by Microscopy Intrusion Porosimetry. MIP tests are performed on representative samples of ground in initial conditions ("in situ" conditions) and final conditions (deformed sample after applying a wetting path that aims to reproduce the saturation of the soil under heavy rains). The resulting measurements allow for the characterization at microstructural level of the soil, identifying the distribution of dominant families pores in the sample and its evolution under external actions. Moreover, comparison of pore size density functions allows defining a microstructural parameter that depends on void ratio and degree of saturation and controls the variation of permeability. Model has been implemented in a thermo-hydro-mechanical code provided with a special boundary condition for climatic actions. Tool is used to analyze pore pressure measurements obtained in the tectonized clay slope. Results are analyzed at the light of the effect that permeability changes during wetting and drying have on the pore pressure regime.

  8. Evaluation of the magnetic and mechanical properties of reactor pressure vessel steels by incremental permeability change curve measurements

    International Nuclear Information System (INIS)

    Ebine, N.; Suzuki, M.

    2001-01-01

    Incremental permeability measurement was performed for two types of structural steels along with the magnetization of their hysteresis minor-loop. The obtained incremental permeability change curve has two sharp peaks, and the width between the two peaks is correlated with the coercivity. Hence the existence of good correlation was verified. On the basis of this result, nondestructive measurement experiments were carried out with planar coils to evaluate changes in the material properties of ferromagnetic structural steel plates. Changes in output voltages from planar coils with different test plates were correlated with their mechanical and magnetic properties. The correlation is so good that the measurement method adopted in this work could be used for nondestructive evaluation of material degradation in ferromagnetic structural steels. (author)

  9. Aberration changes of the corneal anterior surface following discontinued use of rigid gas permeable contact lenses.

    Science.gov (United States)

    Yu, Qing; Wu, Jiang-Xiu; Zhang, He-Ning; Ye, Sheng; Dong, Shi-Qi; Zhang, Chen-Hao

    2013-01-01

    To record aberrations with a corneal topographic device on the anterior surface of the cornea at different time-points prior to wearing and following discontinued use of rigid gas permeable (RGP) contact lenses. The effect of wearing RGP on the anterior surface of the cornea was discussed to provide guidance for clinical refractive error correction. The study objects were 24 eyes from 24 patients. All patients underwent identical examination procedures prior to lens use, as well as afterwards, including slit-lamp examination, non-contact tonometer measurement, computer optometry and corneal curvature measurement, subjective refraction test, and corneal topography analysis. The patients wore contact lenses everyday for 1 month and then discontinued. Corneal topographies were recorded at certain time points of 30 minutes, 1 day, 3, 7 and 14 days following use. Total corneal aberration at each time point following discontinued use of RGP contact lenses was less than the time point prior to use. Detailed results were as follows: root mean square (RMS) (pre)=(1.438±0.328)µm, RMS (30 minutes)=(1.076±0.355)µm, RMS (1 day)=(1.362±0.402)µm, RMS (3 days)=(1.373±0.398)µm, RMS (7 days)=(1.387±0.415)µm, and RMS (14 days)=(1.430±0.423)µm. Results showed that at 30 minutes after discontinued use of RGP contact lenses, almost all 2(nd)- and 3(rd)-order aberrations change. Quadrafoil Z10 and spherical Z12 of the 4(th)-order were also changed. Alterations to Z5, Z6, and Z12 at 1 day after discontinued use were significant differences compared with the time period prior to RGP use: Z5 and Z6 decreased, and Z12 increased slightly. Z5 and Z6 remained decreased at 3 days after discontinued use, but Z9 and Z10 continued to increase and Z12 returned to levels prior to RGP use. At 14 days after discontinued use, all aberrations were not significantly different from the values prior to use. The use RGP contact lenses greatly reduced total aberration of the anterior surface of

  10. Permeability change with dissolution and precipitation reaction induced by highly alkaline plume in packed bed with amorphous silica particles

    International Nuclear Information System (INIS)

    Komatsu, Kyo; Kadowaki, Junichi; Niibori, Yuichi; Mimura, Hitoshi; Usui, Hideo

    2008-01-01

    A large amount of cement is used to construct of the geological disposal system. Such a material alters the pH of groundwater to highly alkaline region. The highly alkaline plume contains rich Ca ion compared to the surrounding environment, and the Ca ion reacts with soluble silicic acid. Its product would deposit on the surface of flow-paths in the natural barrier and decrease the permeability. In this study, the influence of Ca ions in highly alkaline plume on flow-paths has been examined by using packed bed column. The column was packed with the amorphous silica particles of 75-150 μm in diameter. The Ca(OH) 2 solution (0.78 mM, 2.58 mM, 4.37 mM, and 8.48 mM, pH: 12.2-12.4) was continuously injected into the column at a constant flow rate (5 ml/min, and 2 ml/min), and the change of permeability was monitored. At the same time, the concentrations of [Ca] total and [Si] in the eluted solution were measured by the inductively coupled plasma atomic emission spectrometry (ICP-AES). The Ca(OH) 2 solutions were prepared with CO 2 -free pure water, and filtrated through 0.45 μm filter. The permeability was normalized by the initial permeability value. In the experiment results, the permeability dramatically changed with increasing Ca concentration, because Ca ions and H 4 SiO 4 (due to the dissolution of SiO 2 ) produce C-S-H gel between the packed particles in the column. The SEM images and XRD analyses showed that the surface of SiO 2 particles was covered with the C-S-H gel precipitation. On the other hand, when the Ca concentration was relatively low, the permeability did not show remarkable change. For the cross section of SiO 2 particles, EPMA analysis suggested the consumption of Ca in the inner pore of the SiO 2 particles. However, the time-change in the concentrations of Si and Ca was not always simple. Such time-change strongly depended not only on pH or Ca concentration, but also on the flow rates. This suggested that mass transport controls the chemical

  11. Changes in permeability of the alveolar-capillary barrier in firefighters.

    Science.gov (United States)

    Minty, B D; Royston, D; Jones, J G; Smith, D J; Searing, C S; Beeley, M

    1985-09-01

    The effect on alveolar-capillary barrier permeability of chronic exposure to a smoke produced by the partial combusion of diesel oil, paraffin, and wood was examined. An index of permeability was determined from the rate of transfer from the lung into the blood of the hydrophilic, labelled chelate 99mTc diethylene triamine penta-acetate (MW 492 dalton). The results of this test were expressed as the half time clearance of the tracer from the lung into the blood (T1/2 LB). The study was carried out at the Royal Naval Firefighting School, HMS Excellent. Permeability index was measured on seven non-smoking naval firefighting instructors who had worked at the school for periods of longer than two and a half months. Tests of airway function and carbon monoxide transfer factor were performed on four of these seven instructors. The results of the permeability index showed a T1/2 LB of 26 min +/- 5 (SEM) which differed significantly from that of normal non-smokers. By contrast all other lung function tests had values within the predicted normal range.

  12. Permeability changes of coal cores and briquettes under tri-axial stress conditions

    Czech Academy of Sciences Publication Activity Database

    Wierzbicki, M.; Konečný, Pavel; Kožušníková, Alena

    2014-01-01

    Roč. 59, č. 4 (2014), s. 1129-1138 ISSN 0860-7001 R&D Projects: GA MŠk ED2.1.00/03.0082 Institutional support: RVO:68145535 Keywords : coal * gas permeability * tri-axial stress * coal briquettes Subject RIV: DH - Mining, incl. Coal Mining Impact factor: 0.608, year: 2013 http://mining.archives.pl

  13. Climate change: potential implications for Ireland's biodiversity

    Science.gov (United States)

    Donnelly, Alison

    2018-03-01

    A national biodiversity and climate change adaptation plan is being developed for Ireland by the Department of Communications, Climate Action, and Environment. In order to inform such a plan, it was necessary to review and synthesize some of the recent literature pertaining to the impact of climate change on biodiversity in Ireland. Published research on this topic fell within three broad categories: (i) changes in the timing of life-cycle events (phenology) of plants, birds, and insects; (ii) changes in the geographic range of some bird species; and (iii) changes in the suitable climatic zones of key habitats and species. The synthesis revealed evidence of (i) a trend towards earlier spring activity of plants, birds, and insects which may result in a change in ecosystem function; (ii) an increase in the number of bird species; and (iii) both increases and decreases in the suitable climatic area of key habitats and species, all of which are expected to impact Ireland's future biodiversity. This process identified data gaps and limitations in available information both of which could be used to inform a focused research strategy. In addition, it raises awareness of the potential implications of climate change for biodiversity in Ireland and elsewhere and demonstrates the need for biodiversity conservation plans to factor climate change into future designs.

  14. Aberration changes of the corneal anterior surface following discontinued use of rigid gas permeable contact lenses

    Directory of Open Access Journals (Sweden)

    Shi-Qi Dong

    2013-04-01

    Full Text Available AIM: To record aberrations with a corneal topographic device on the anterior surface of the cornea at different time-points prior to wearing and following discontinued use of rigid gas permeable (RGP contact lenses. The effect of wearing RGP on the anterior surface of the cornea was discussed to provide guidance for clinical refractive error correction. METHODS: The study objects were 24 eyes from 24 patients. All patients underwent identical examination procedures prior to lens use, as well as afterwards, including slit-lamp examination, non-contact tonometer measurement, computer optometry and corneal curvature measurement, subjective refraction test, and corneal topography analysis. The patients wore contact lenses everyday for 1 month and then discontinued. Corneal topographies were recorded at certain time points of 30 minutes, 1 day, 3, 7 and 14 days following use. RESULTS: Total corneal aberration at each time point following discontinued use of RGP contact lenses was less than the time point prior to use. Detailed results were as follows:root mean square (RMS (pre=(1.438±0.328μm, RMS (30 minutes=(1.076±0.355μm, RMS (1 day=(1.362±0.402μm, RMS (3 days=(1.373±0.398μm, RMS (7 days=(1.387±0.415μm, and RMS (14 days=(1.430±0.423μm. Results showed that at 30 minutes after discontinued use of RGP contact lenses, almost all 2nd- and 3rd-order aberrations change. Quadrafoil Z10 and spherical Z12 of the 4th-order were also changed. Alterations to Z5, Z6, and Z12 at 1 day after discontinued use were significant differences compared with the time period prior to RGP use:Z5 and Z6 decreased, and Z12 increased slightly. Z5 and Z6 remained decreased at 3 days after discontinued use, but Z9 and Z10 continued to increase and Z12 returned to levels prior to RGP use. At 14 days after discontinued use, all aberrations were not significantly different from the values prior to use. CONCLUSION: The use RGP contact lenses greatly reduced total

  15. Experimental observation of permeability changes in dolomite at CO2 sequestration conditions.

    Science.gov (United States)

    Tutolo, Benjamin M; Luhmann, Andrew J; Kong, Xiang-Zhao; Saar, Martin O; Seyfried, William E

    2014-02-18

    Injection of cool CO2 into geothermally warm carbonate reservoirs for storage or geothermal energy production may lower near-well temperature and lead to mass transfer along flow paths leading away from the well. To investigate this process, a dolomite core was subjected to a 650 h, high pressure, CO2 saturated, flow-through experiment. Permeability increased from 10(-15.9) to 10(-15.2) m(2) over the initial 216 h at 21 °C, decreased to 10(-16.2) m(2) over 289 h at 50 °C, largely due to thermally driven CO2 exsolution, and reached a final value of 10(-16.4) m(2) after 145 h at 100 °C due to continued exsolution and the onset of dolomite precipitation. Theoretical calculations show that CO2 exsolution results in a maximum pore space CO2 saturation of 0.5, and steady state relative permeabilities of CO2 and water on the order of 0.0065 and 0.1, respectively. Post-experiment imagery reveals matrix dissolution at low temperatures, and subsequent filling-in of flow passages at elevated temperature. Geochemical calculations indicate that reservoir fluids subjected to a thermal gradient may exsolve and precipitate up to 200 cm(3) CO2 and 1.5 cm(3) dolomite per kg of water, respectively, resulting in substantial porosity and permeability redistribution.

  16. Measurement of choroid plexus perfusion using dynamic susceptibility MR imaging: capillary permeability and age-related changes

    Energy Technology Data Exchange (ETDEWEB)

    Bouzerar, Roger; Chaarani, Bader; Baledent, Olivier [University Hospital, Image Processing Department, Amiens (France); Gondry-Jouet, Catherine [University Hospital, Radiology Department, Amiens (France); Zmudka, Jadwiga [University Hospital, Geriatric Unit, Amiens (France)

    2013-12-15

    The cerebrospinal fluid (CSF) plays a major role in the physiology of the central nervous system. The continuous turnover of CSF is mainly attributed to the highly vascularized choroid plexus (CP) located in the cerebral ventricles which represent a complex interface between blood and CSF. We propose a method for evaluating CP functionality in vivo using perfusion MR imaging and establish the age-related changes of associated parameters. Fifteen patients with small intracranial tumors were retrospectively studied. MR Imaging was performed on a 3T MR Scanner. Gradient-echo echo planar images were acquired after bolus injection of gadolinium-based contrast agent (CA). The software developed used the combined T1- and T2-effects. The decomposition of the relaxivity signals enables the calculation of the CP capillary permeability (K{sub 2}). The relative cerebral blood volume (rCBV), mean transit time (MTT), and signal slope decrease (SSD) were also calculated. The mean permeability K{sub 2} of the extracted CP was 0.033+/-0.18 s{sup -1}. K{sub 2} and SSD significantly decreased with subject's age whereas MTT significantly increased with subject's age. No significant correlation was found for age-related changes in rCBV and rCBF. The decrease in CP permeability is in line with the age-related changes in CSF secretion observed in animals. The MTT increase indicates significant structural changes corroborated by microscopy studies in animals or humans. Overall, DSC MR-perfusion enables an in vivo evaluation of the hemodynamic state of CP. Clinical applications such as neurodegenerative diseases could be considered thanks to specific functional studies of CP. (orig.)

  17. Lattice Boltzmann simulation of dissolution-induced changes in permeability and porosity in 3D CO2 reactive transport

    Science.gov (United States)

    Tian, Zhiwei; Wang, Junye

    2018-02-01

    Dissolution and precipitation of rock matrix are one of the most important processes of geological CO2 sequestration in reservoirs. They change connections of pore channels and properties of matrix, such as bulk density, microporosity and hydraulic conductivity. This study builds on a recently developed multi-layer model to account for dynamic changes of microporous matrix that can accurately predict variations in hydraulic properties and reaction rates due to dynamic changes in matrix porosity and pore connectivity. We apply the model to simulate the dissolution and precipitation processes of rock matrix in heterogeneous porous media to quantify (1) the effect of the reaction rate on dissolution and matrix porosity, (2) the effect of microporous matrix diffusion on the overall effective diffusion and (3) the effect of heterogeneity on hydraulic conductivity. The results show the CO2 storage influenced by factors including the matrix porosity change, reaction front movement, velocity and initial properties. We also simulated dissolution-induced permeability enhancement as well as effects of initial porosity heterogeneity. The matrix with very low permeability, which can be unresolved on X-ray CT, do contribute to flow patterns and dispersion. The concentration of reactant H+ increases along the main fracture paths where the flow velocity increases. The product Ca++ shows the inversed distribution pattern against the H+ concentration. This demonstrates the capability of this model to investigate the complex CO2 reactive transport in real 3D heterogeneous porous media.

  18. Change in rabbit skin permeability with combined exposure to laser and roentgen emissions

    Energy Technology Data Exchange (ETDEWEB)

    Mkheyan, V.E.; Ayrapetyan, F.O.; Khachatryan, A.A.

    1976-01-01

    The authors examined disturbances of tissue permeability in rabbits due to laser and x-rays. Experiments were conducted on 20 albino rabbits (2 to 2.5 kg in weight) with five as a control group. A mixture of enzyme with coloring was injected into the animals and then they were exposed to laser apparatus Arzii-206 with waves 6943 A, energy pulse 4 J, and the x-ray therapy apparatus RUM-11 with a dose of 650 r using standard conditions. After 24, 48, 72, and 96 hours, the area of coloring in the rabbits' skins was measured and compared with the control. Dispersion in the exposed rabbits was initially 1.5 to 2 times greater than in the control group. The exposed animals approached the norm in a later period ( on the 30 to 35th day). When animals were exposed to the combined rays and then injected with the coloring and enzymes, the index of color dispersion was 1.5 times greater than in the control group. In the first three days after the test, skin permeability increased due to radiation depolymerization of skin hyaluronic acids. 9 references, 2 figures.

  19. Fracture Propagation and Permeability Change under Poro-thermoelastic Loads & Silica Reactivity in Enhanced Geothermal Systems

    Energy Technology Data Exchange (ETDEWEB)

    Ahmad Ghassemi

    2009-10-01

    Geothermal energy is recovered by circulating water through heat exchange areas within a hot rock mass. Geothermal reservoir rock masses generally consist of igneous and metamorphic rocks that have low matrix permeability. Therefore, cracks and fractures play a significant role in extraction of geothermal energy by providing the major pathways for fluid flow and heat exchange. Therefore, knowledge of the conditions leading to formation of fractures and fracture networks is of paramount importance. Furthermore, in the absence of natural fractures or adequate connectivity, artificial fractures are created in the reservoir using hydraulic fracturing. Multiple fractures are preferred because of the large size necessary when using only a single fracture. Although the basic idea is rather simple, hydraulic fracturing is a complex process involving interactions of high pressure fluid injections with a stressed hot rock mass, mechanical interaction of induced fractures with existing natural fractures, and the spatial and temporal variations of in-situ stress. As a result, it is necessary to develop tools that can be used to study these interactions as an integral part of a comprehensive approach to geothermal reservoir development, particularly enhanced geothermal systems. In response to this need we have developed advanced poro-thermo-chemo-mechanical fracture models for rock fracture research in support of EGS design. The fracture propagation models are based on a regular displacement discontinuity formulation. The fracture propagation studies include modeling interaction of induced fractures. In addition to the fracture propagation studies, two-dimensional solution algorithms have been developed and used to estimate the impact of pro-thermo-chemical processes on fracture permeability and reservoir pressure. Fracture permeability variation is studied using a coupled thermo-chemical model with quartz reaction kinetics. The model is applied to study quartz precipitation

  20. Experimental observation and numerical simulation of permeability changes in dolomite at CO2 sequestration conditions

    Science.gov (United States)

    Tutolo, B. M.; Luhmann, A. J.; Kong, X.; Saar, M. O.; Seyfried, W. E.

    2013-12-01

    Injecting surface temperature CO2 into geothermally warm reservoirs for geologic storage or energy production may result in depressed temperature near the injection well and thermal gradients and mass transfer along flow paths leading away from the well. Thermal gradients are particularly important to consider in reservoirs containing carbonate minerals, which are more soluble at lower temperatures, as well as in CO2-based geothermal energy reservoirs where lowering heat exchanger rejection temperatures increases efficiency. Additionally, equilibrating a fluid with cation-donating silicates near a low-temperature injection well and transporting the fluid to higher temperature may enhance the kinetics of mineral precipitation in such a way as to overcome the activation energy required for mineral trapping of CO2. We have investigated this process by subjecting a dolomite core to a 650-hour temperature series experiment in which the fluid was saturated with CO2 at high pressure (110-126 bars) and 21°C. This fluid was recirculated through the dolomite core, increasing permeability from 10-16 to 10-15.2 m2. Subsequently, the core temperature was raised to 50° C, and permeability decreased to 10-16.2 m2 after 289 hours, due to thermally-driven CO2 exsolution. Increasing core temperature to 100°C for the final 145 hours of the experiment caused dolomite to precipitate, which, together with further CO2 exsolution, decreased permeability to 10-16.4 m2. Post-experiment x-ray computed tomography and scanning electron microscope imagery of the dolomite core reveals abundant matrix dissolution and enlargement of flow paths at low temperatures, and subsequent filling-in of the passages at elevated temperature by dolomite. To place this experiment within the broader context of geologic CO2 sequestration, we designed and utilized a reactive transport simulator that enables dynamic calculation of CO2 equilibrium constants and fugacity and activity coefficients by incorporating

  1. Stress, strain, and temperature induced permeability changes in potential repository rocks

    International Nuclear Information System (INIS)

    Heard, H.C.; Duba, A.

    1977-01-01

    Work is in progress to assess the permeability characteristics of coarse-grained igneous rocks as affected by pressure, deviatoric stress, and temperature. In order to predict the long-term behavior of these rocks, both virgin and fractured, permeability and all principal strains resulting from an imposed deviatoric stress under various simulated lithostatic pressures are being measured. In addition, compressional as well as shear velocities and electrical conductivity are being evaluated along these principal directions. These simultaneous measurements are being made initially at 25 0 C on a 15 cm diameter by 30 cm long sample in a pressure apparatus controlled by a mini-computer. Correlation of these data with similar field observations should then allow simplified exploration for a suitable repository site as well as the prediction of the response of a mined cavity with both distance and time at this site. After emplacement of the waste canisters, the mechanical stability and hydrologic integrity of this mined repository will be directly influenced by the fracturing of the surrounding rock which results from local temperature differences and the thermal expansion of that rock. Temperatures (and, hence, these differences) in the vicinity of the repository are expected to be affected by the presence of pore fluids (single- or two-phase) in the rock, the heat capacity and the thermal conductivity of this system. In turn, these are all dependent upon lithostatic pressure, pore pressure, and stress. Thermal expansion (and fracturing) will also be affected by the lithostatic (and effective) pressure, the deviatoric stress field, and the initial anisotropy of the rock

  2. Effect of Flow Direction on Relative Permeability Curves in Water/Gas Reservoir System: Implications in Geological CO2 Sequestration

    Directory of Open Access Journals (Sweden)

    Abdulrauf Rasheed Adebayo

    2017-01-01

    Full Text Available The effect of gravity on vertical flow and fluids saturation, especially when flow is against gravity, is not often a subject of interest to researchers. This is because of the notion that flow in subsurface formations is usually in horizontal direction and that vertical flow is impossible or marginal because of the impermeable shales or silts overlying them. The density difference between two fluids (usually oil and water flowing in the porous media is also normally negligible; hence gravity influence is neglected. Capillarity is also often avoided in relative permeability measurements in order to satisfy some flow equations. These notions have guided most laboratory core flooding experiments to be conducted in horizontal flow orientation, and the data obtained are as good as what the experiments tend to mimic. However, gravity effect plays a major role in gas liquid systems such as CO2 sequestration and some types of enhanced oil recovery techniques, particularly those involving gases, where large density difference exists between the fluid pair. In such cases, laboratory experiments conducted to derive relative permeability curves should take into consideration gravity effects and capillarity. Previous studies attribute directional dependence of relative permeability and residual saturations to rock anisotropy. It is shown in this study that rock permeability, residual saturation, and relative permeability depend on the interplay between gravity, capillarity, and viscous forces and also the direction of fluid flow even when the rock is isotropic. Rock samples representing different lithology and wide range of permeabilities were investigated through unsteady-state experiments covering drainage and imbibition in both vertical and horizontal flow directions. The experiments were performed at very low flow rates to capture capillarity. The results obtained showed that, for each homogeneous rock and for the same flow path along the core length

  3. Oceanic implications for climate change policy

    International Nuclear Information System (INIS)

    McNeil, Ben I.

    2006-01-01

    Under the United Nations convention on the law of the sea (1982), each participating country maintains exclusive economic and environmental rights within the oceanic region extending 200 nm from its territorial sea, known as the exclusive economic zone (EEZ). Although the ocean within each EEZ is undoubtedly an anthropogenic CO 2 sink, it has been over-looked within international climate policy. In this paper I use an area-weighted scaling argument to show that the inclusion of the EEZ CO 2 sink within national carbon accounts would have significant implications in tracking national greenhouse commitments to any future climate change policy initiative. The advantages and disadvantages for inclusion of the EEZ CO 2 sink into global climate change policy are also explored. The most compelling argument for including the EEZ CO 2 sink is that it would enhance the equity and resources among coastal nations to combat and adapt against future climate change that will inherently impact coastal nations more so than land locked nations. If included, the funds raised could be used for either monitoring or adaptive coastal infrastructure among the most vulnerable nations. On the other hand, the EEZ anthropogenic CO 2 sink cannot be directly controlled by human activities and could be used as a disincentive for some developed nations to reduce fossil-fuel related greenhouse gas emissions. This may therefore dampen efforts to ultimately reduce atmospheric greenhouse gas concentrations. In consideration of these arguments it is therefore suggested that an 'EEZ clause' be added to Kyoto and any future international climate policy that explicitly excludes its use within national carbon accounts under these international climate frameworks

  4. Plasma proteins in a standardised skin mini-erosion (I: permeability changes as a function of time

    Directory of Open Access Journals (Sweden)

    Ryan Terence J

    2002-02-01

    Full Text Available Abstract Background A standardised technique using a suction-induced mini-erosion that allows serial sampling of dermal interstitial fluid (IF for 5 to 6 days has been described. In the present study, we studied permeability changes as a function of time. Methods We examined IF concentrations of total protein concentration and the concentration of insulin (6.6 kDa, prealbumin (55 kDa, albumin (66 kDa, transferrin (80 kDa, IgG (150 kDa and alpha-2-macroglobulin (720 kDa as a function of time, using an extraction pressure of 200 mmHg below atmospheric. Results At 0 h after forming the erosion, mean total IF protein content (relative to plasma was 26 ± 13% (SD. For the individual proteins, the relative mean concentrations were 65 ± 36% for insulin, 48 ± 12% for albumin, 30 ± 19% for transferrin, 31 ± 15%for IgG and 19.5 ± 10% for alpha-2-macroglobulin. At 24 h, the total IF protein content was higher than at 0 h (56 ± 26% vs 26 ± 13%; p Conclusions The results indicate that fluid sampled at 0 h after forming the erosion represents dermal IF before the full onset of inflammation. From 24 h onward, the sampled fluid reflects a steady state of increased permeability induced by inflammation. This technique is promising as a tool for clinically sampling substances that are freely distributed in the body and as a model for studying inflammation and vascular permeability.

  5. Environmental health implications of global climate change

    Energy Technology Data Exchange (ETDEWEB)

    Watson, Robert T.; Patz, Jonathan; Gubler, Duane J.; Parson, Edward A.; Vincent, James H.

    2005-07-01

    This paper reviews the background that has led to the now almost-universally held opinion in the scientific community that global climate change is occurring and is inescapably linked with anthropogenic activity. The potential implications to human health are considerable and very diverse. These include, for example, the increased direct impacts of heat and of rises in sea level, exacerbated air and water-borne harmful agents, and - associated with all the preceding - the emergence of environmental refugees. Vector-borne diseases, in particular those associated with blood-sucking arthropods such as mosquitoes, may be significantly impacted, including redistribution of some of those diseases to areas not previously affected. Responses to possible impending environmental and public health crises must involve political and socio-economic considerations, adding even greater complexity to what is already a difficult challenge. In some areas, adjustments to national and international public health practices and policies may be effective, at least in the short and medium terms. But in others, more drastic measures will be required. Environmental monitoring, in its widest sense, will play a significant role in the future management of the problem. (Author)

  6. Ultra high pressure liquid chromatography. Column permeability and changes of the eluent properties.

    Science.gov (United States)

    Gritti, Fabrice; Guiochon, Georges

    2008-04-11

    The behavior of four similar liquid chromatography columns (2.1mm i.d. x 30, 50, 100, and 150 mm, all packed with fine particles, average d(p) approximately 1.7 microm, of bridged ethylsiloxane/silica hybrid-C(18), named BEH-C(18)) was studied in wide ranges of temperature and pressure. The pressure and the temperature dependencies of the viscosity and the density of the eluent (pure acetonitrile) along the columns were also derived, using the column permeabilities and applying the Kozeny-Carman and the heat balance equations. The heat lost through the external surface area of the chromatographic column was directly derived from the wall temperature of the stainless steel tube measured with a precision of +/-0.2 degrees C in still air and +/-0.1 degrees C in the oven compartment. The variations of the density and viscosity of pure acetonitrile as a function of the temperature and pressure was derived from empirical correlations based on precise experimental data acquired between 298 and 373 K and at pressures up to 1.5 kbar. The measurements were made with the Acquity UPLC chromatograph that can deliver a maximum flow rate of 2 mL/min and apply a maximum column inlet pressure of 1038 bar. The average Kozeny-Carman permeability constant of the columns was 144+/-3.5%. The temperature hence the viscosity and the density profiles of the eluent along the column deviate significantly from linear behavior under high-pressure gradients. For a 1000 bar pressure drop, we measured DeltaT=25-30 K, (Deltaeta/eta) approximately 100%, and (Deltarho/rho) approximately 10%. These results show that the radial temperature profiles are never fully developed within 1% for any of the columns, even under still-air conditions. This represents a practical advantage regarding the apparent column efficiency at high flow rates, since the impact of the differential analyte velocity between the column center and the column wall is not maximum. The interpretation of the peak profiles recorded in

  7. Notional Permeability

    NARCIS (Netherlands)

    Kik, R.; Van den Bos, J.P.; Maertens, J.; Verhagen, H.J.; Van der Meer, J.W.

    2012-01-01

    Different layer design of a rock slope and under layers has a large effect on the strengths on the rock slope itself. In the stability formula developed of VAN DER MEER [1988] this effect is represented by the term Notional Permeability with symbol P. A more open, or permeable, structure underneath

  8. Implications of climate change for tourism in Australia

    NARCIS (Netherlands)

    Amelung, B.; Nicholls, S.

    2014-01-01

    This study assesses the impacts of projected climate change on Australia's tourism industry. Based on application of the Tourism Climatic Index, it investigates potential changes in climatic attractiveness for Australia's major destinations, and discusses implications for tourist flows and tourism

  9. Climate Change: Implications for South African Building Systems and Components

    CSIR Research Space (South Africa)

    Gibberd, Jeremy T

    2017-12-01

    Full Text Available to determine the implications of these changes for buildings. Proposals are made on how buildings may be adapted to climate change and recommendations on further research and development are outlined....

  10. changing stm curricula for the information age: implications

    African Journals Online (AJOL)

    TONIA CLARE

    information age, rationale and strategies for changing STM curricular, implications for the teacher and then conclusion. ... learner under the guidance of a school to effect a change in the ..... education international conference. Ofele, C. N. ...

  11. Introducing change in organization: implication for human resource ...

    African Journals Online (AJOL)

    Introducing change in organization: implication for human resource ... that one of the most obvious and urgent problems at management level in organizations is ... to change their attitude and behavior as rapidly as their organization requires.

  12. Permeability of porour rhyolite

    Science.gov (United States)

    Cashman, K.; Rust, A.; Wright, H.; Roberge, J.

    2003-04-01

    connecting individual vesicles. This interpretation is supported by the observation that clasts with high porosities but unusually low k1 and k2 also have high percentages of isolated pores (>10%), indicating extensive vesiculation but limited bubble coalescence; such clasts seem to be characteristic of ignimbrite deposits. 1Innocentini MDM, Salvini VR, Pandolfelli VC, Coury JC (1999) The permeability of ceramic foams. Amer Ceram Soc Bull 79:78-94. 2Klug C, Cashman KV (1996) Permeability development in vesiculating magmas - implications for fragmentation. Bull. Volcanol.58:87-100; Klug C, Cashman KV, Bacon C (2002) Structure and physical characteristics of pumice from the climactic eruption of Mt. Mazama (Crater Lake), Oregon. Bull Volcanol 64:486-501

  13. Changes of the groundwater composition in fractured rocks of low permeability as a consequence of deglaciation

    International Nuclear Information System (INIS)

    Delos, A.; Duro, L.; Guimera, J.; Bruno, J.; Puigdomenech, I.

    2005-01-01

    ) Effects of ice melting and redox front migration in fractured rocks of low permeability. SKB TR-99-19, 86 pp [3] Gascoyne, M. (1999) Long-term maintenance of reducing conditions in a spent nuclear fuel repository. A re-examination of critical factors. SKB R 99-41, 56 pp. (authors)

  14. Pore Structure and Diagenetic Controls on Relative Permeability: Implications for Enhanced Oil Recovery and CO2 Storage

    Science.gov (United States)

    Feldman, J.; Dewers, T. A.; Heath, J. E.; Cather, M.; Mozley, P.

    2016-12-01

    Multiphase flow in clay-bearing sandstones of the Morrow Sandstone governs the efficiency of CO2 storage and enhanced oil recovery at the Farnsworth Unit, Texas. This formation is the target for enhanced oil recovery and injection of one million metric ton of anthropogenically-sourced CO2. The sandstone hosts eight major flow units that exhibit distinct microstructural characteristics due to diagenesis, including: "clean" macro-porosity; quartz overgrowths constricting some pores; ghost grains; intergranular porosity filled by microporous authigenic clay; and feldspar dissolution. We examine the microstructural controls on macroscale (core scale) relative permeability and capillary pressure behavior through: X-ray computed tomography, Robomet.3d, and focused ion beam-scanning electron microscopy imaging of the pore structure of the major flow units of the Morrow Sandstone; relative permeability and capillary pressure in the laboratory using CO2, brine, and oil at reservoir pressure and effective stress conditions. The combined data sets inform links between patterns of diagenesis and multiphase flow. These data support multiphase reservoir simulation and performance assessment by the Southwest Regional Partnership on Carbon Sequestration (SWP). Funding for this project is provided by the U.S. Department of Energy's National Energy Technology Laboratory through the SWP under Award No. DE-FC26-05NT42591. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  15. Global Climate Change: National Security Implications

    Science.gov (United States)

    2008-05-01

    it cost to treat asthma in children and other health problems caused by the dirt we were putting out of the smokestacks. It was passed by the...in Latin America for a number of years. General Clark used to say, “In SOUTHCOM, take no credit and expect none.” And I think that was a good rule...damage the health of our children .35 People also need to better understand the implications of globalization. Not all currently appreciate how our

  16. Blood-retinal barrier glycerol permeability in diabetic macular edema and healthy eyes: estimations from macular volume changes after peroral glycerol

    DEFF Research Database (Denmark)

    Thornit, Dorte Nellemann; Vinten, Carl Martin; Sander, Birgit

    2010-01-01

    PURPOSE: To compare the changes in macular volume (MV) between healthy subjects and patients with diabetic macular edema (DME) after an osmotic load and to determine the glycerol permeability (P(gly)) of the blood-retinal barrier (BRB). METHODS: In this unmasked study, 13 patients with DME and 5...

  17. Cisplatin impairs rat liver mitochondrial functions by inducing changes on membrane ion permeability: Prevention by thiol group protecting agents

    International Nuclear Information System (INIS)

    Custodio, Jose B.A.; Cardoso, Carla M.P.; Santos, Maria S.; Almeida, Leonor M.; Vicente, Joaquim A.F.; Fernandes, Maria A.S.

    2009-01-01

    Cisplatin (CisPt) is the most important platinum anticancer drug widely used in the treatment of head, neck, ovarian and testicular cancers. However, the mechanisms by which CisPt induces cytotoxicity, namely hepatotoxicity, are not completely understood. The goal of this study was to investigate the influence of CisPt on rat liver mitochondrial functions (Ca 2+ -induced mitochondrial permeability transition (MPT), mitochondrial bioenergetics, and mitochondrial oxidative stress) to better understand the mechanism underlying its hepatotoxicity. The effect of thiol group protecting agents and some antioxidants against CisPt-induced mitochondrial damage was also investigated. Treatment of rat liver mitochondria with CisPt (20 nmol/mg protein) induced Ca 2+ -dependent mitochondrial swelling, depolarization of membrane potential (ΔΨ), Ca 2+ release, and NAD(P)H fluorescence intensity decay. These effects were prevented by cyclosporine A (CyA), a potent and specific inhibitor of the MPT. In the concentration range of up to 40 nmol/mg protein, CisPt slightly inhibited state 3 and stimulated state 2 and state 4 respiration rates using succinate as respiratory substrate. The respiratory indexes, respiratory control ratio (RCR) and ADP/O ratios, the ΔΨ, and the ADP phosphorylation rate were also depressed. CisPt induced mitochondrial inner membrane permeabilization to protons (proton leak) but did not induce significant changes on mitochondrial H 2 O 2 generation. All the effects induced by CisPt on rat liver mitochondria were prevented by thiol group protecting agents namely, glutathione (GSH), dithiothreitol (DTT), N-acetyl-L-cysteine (NAC) and cysteine (CYS), whereas superoxide-dismutase (SOD), catalase (CAT) and ascorbate (ASC) were without effect. In conclusion, the anticancer drug CisPt: (1) increases the sensitivity of mitochondria to Ca 2+ -induced MPT; (2) interferes with mitochondrial bioenergetics by increasing mitochondrial inner membrane permeabilization to

  18. Global Climate Change: National Security Implications

    National Research Council Canada - National Science Library

    Pumphrey, Carolyn

    2008-01-01

    .... But this notion was generally scoffed at. Over the course of the 20th century, the scientific community gradually came to terms with this theory and began to regard climate change even rapid climate change as more than a distant possibility...

  19. The Changing Research Context: Implications for Leadership

    Science.gov (United States)

    Billot, Jennie

    2011-01-01

    Within the changing tertiary environment, research activity and performance are coming under greater pressure and scrutiny. External policy and funding directives are resulting in revised institutional objectives, requiring variations to organisational structures and processes. These changes have an impact on the relationship between the…

  20. Anthropometric change: implications for office ergonomics.

    Science.gov (United States)

    Gordon, Claire C; Bradtmiller, Bruce

    2012-01-01

    Well-designed office workspaces require good anthropometric data in order to accommodate variability in the worker population. The recent obesity epidemic carries with it a number of anthropometric changes that have significant impact on design. We examine anthropometric change among US civilians over the last 50 years, and then examine that change in a subset of the US population--the US military--as military data sets often have more ergonomic dimensions than civilian ones. The civilian mean stature increased throughout the period 1962 to 2006 for both males and females. However, the rate of increase in mean weight was considerably faster. As a result, the male obesity rate changed from 10.7% in 1962 to 31.3% in 2006. The female change for the same period was 15.8% to 33.2%. In the Army, the proportion of obesity increased from 3.6% to 20.9%, in males. In the absence of national US ergonomic data, we demonstrate one approach to tracking civilian change in these dimensions, applying military height/weight regression equations to the civilian population estimates. This approach is useful for population monitoring but is not suitable for establishing new design limits, as regression estimates likely underestimate the change at the ends of the distribution.

  1. Spatial resolution of gas hydrate and permeability changes from ERT data in LARS simulating the Mallik gas hydrate production test

    Science.gov (United States)

    Priegnitz, Mike; Thaler, Jan; Spangenberg, Erik; Schicks, Judith M.; Abendroth, Sven

    2014-05-01

    The German gas hydrate project SUGAR studies innovative methods and approaches to be applied in the production of methane from hydrate-bearing reservoirs. To enable laboratory studies in pilot scale, a large reservoir simulator (LARS) was realized allowing for the formation and dissociation of gas hydrates under simulated in-situ conditions. LARS is equipped with a series of sensors. This includes a cylindrical electrical resistance tomography (ERT) array composed of 25 electrode rings featuring 15 electrodes each. The high-resolution ERT array is used to monitor the spatial distribution of the electrical resistivity during hydrate formation and dissociation experiments over time. As the present phases of poorly conducting sediment, well conducting pore fluid, non-conducting hydrates, and isolating free gas cover a wide range of electrical properties, ERT measurements enable us to monitor the spatial distribution of these phases during the experiments. In order to investigate the hydrate dissociation and the resulting fluid flow, we simulated a hydrate production test in LARS that was based on the Mallik gas hydrate production test (see abstract Heeschen et al., this volume). At first, a hydrate phase was produced from methane saturated saline water. During the two months of gas hydrate production we measured the electrical properties within the sediment sample every four hours. These data were used to establish a routine estimating both the local degrees of hydrate saturation and the resulting local permeabilities in the sediment's pore space from the measured resistivity data. The final gas hydrate saturation filled 89.5% of the total pore space. During hydrate dissociation, ERT data do not allow for a quantitative determination of free gas and remaining gas hydrates since both phases are electrically isolating. However, changes are resolved in the spatial distribution of the conducting liquid and the isolating phase with gas being the only mobile isolating phase

  2. Climate Change: Science and Policy Implications

    National Research Council Canada - National Science Library

    Leggett, Jane A

    2007-01-01

    .... During the 20th Century, some areas became wetter while others experienced more drought. Most climate scientists conclude that humans have induced a large part of the climate change since the 1970s...

  3. Climate Change: Science and Policy Implications

    National Research Council Canada - National Science Library

    Leggett, Jane A

    2007-01-01

    .... Although natural forces such as solar irradiance and volcanoes contribute to variability, scientists cannot explain the climate changes of the past few decades without including the effects of elevated greenhouse gas (GHG...

  4. Global change and its implications for Alaska

    International Nuclear Information System (INIS)

    Weller, G.

    1993-01-01

    In the 1980s versions of climate models, the Arctic and Antarctic regions were considered crucial in understanding and predicting climate change, and there is also agreement that climate change will have large impacts in the Arctic since the climate signal is amplified at high latitudes. The earlier climate change scenarios are re-examined for the case of Alaska, in light of more recent information. Observational evidence in the Arctic over the last few decades agrees well with predictions of a current global climate model, including temperature increase over land masses of up to 1 degree C per decade in winter, with smaller changes in summer. Other indirect evidence of a warmer Arctic climate includes receding glaciers and warmer permafrost temperatures. It is predicted that after the CO 2 content of the atmosphere doubles, winter temperatures in Alaska will increase 6-8 degree C. In much of the interior, mean annual temperature will rise above freezing, leading to disappearance of discontinuous permafrost. The growing season would be lengthened by about three weeks, vegetation types and the abundance and distribution of mammals will change, and there will be less sea ice along coastal areas. Impacts on human activities will be both adverse and favorable; for example, in the petroleum industry, maintenance of pipelines and roads will be more difficult but offshore exploration and marine supply operations will be made easier. 6 refs., 3 tabs

  5. Radiation induced changes in the airway - anaesthetic implications ...

    African Journals Online (AJOL)

    Radiation induced changes in the airway - anaesthetic implications: case report. Mallika Balakrishnan, Renju Kuriakose, Rachel Cherian Koshy. Abstract. Radiation induces a variety of changes in the airway that can potentially lead to difficult intubation. Osteoradionecrosis (ORN) of the mandible, a severe consequence of ...

  6. IMPLICATIONS OF CLIMATE CHANGE ON HUMAN COMFORT

    African Journals Online (AJOL)

    Prince Acheampong

    the dry season, are getting hotter and drier with increased heat waves. Increased ... about some of the possible impacts of climate change on the built environment. This is to set the ... Non-physical effects such as increased energy demand for ...

  7. Climate Change Planning for Military Installations: Findings and Implications

    Science.gov (United States)

    2010-10-01

    climate change as an emerging issue with potential national security implications. As a result of these concerns, the DoD Strategic Environmental Research and Development Program (SERDP) is establishing a research and development program to address climate change effects on DoD installations and associated missions. To help establish the program, SERDP tasked Noblis to identify potential climate change effects on military installations and their missions and operations. This report presents the findings portion of this study and

  8. Influence of infiltrated water on the change of formation water and oil permeability of crude oil bearing rocks

    Energy Technology Data Exchange (ETDEWEB)

    Cubric, S

    1970-09-01

    A brief desription is given of the causes of permeability reduction of oil-bearing rocks, due to well damage during the drilling and well completion or when working over wells. The physical properties of 2-phase flow (crude oil-water) and the possibility of increasing the existing permeability of the formation, because of the water infiltrated from the well into the crude oil layer, are described in detail. Field examples show that there are such cases, and that the artificially increased existing permeability of water-bearing rocks can be reduced and even brought to normal, if the adjacent formation zone layer is treated with surfactants (e.g., Hyflo dissolved in crude oil).

  9. Numerical Simulation of Permeability Change in Wellbore Cement Fractures after Geomechanical Stress and Geochemical Reactions Using X-ray Computed Tomography Imaging.

    Science.gov (United States)

    Kabilan, Senthil; Jung, Hun Bok; Kuprat, Andrew P; Beck, Anthon N; Varga, Tamas; Fernandez, Carlos A; Um, Wooyong

    2016-06-21

    X-ray microtomography (XMT) imaging combined with three-dimensional (3D) computational fluid dynamics (CFD) modeling technique was used to study the effect of geochemical and geomechanical processes on fracture permeability in composite Portland cement-basalt caprock core samples. The effect of fluid density and viscosity and two different pressure gradient conditions on fracture permeability was numerically studied by using fluids with varying density and viscosity and simulating two different pressure gradient conditions. After the application of geomechanical stress but before CO2-reaction, CFD revealed fluid flow increase, which resulted in increased fracture permeability. After CO2-reaction, XMT images displayed preferential precipitation of calcium carbonate within the fractures in the cement matrix and less precipitation in fractures located at the cement-basalt interface. CFD estimated changes in flow profile and differences in absolute values of flow velocity due to different pressure gradients. CFD was able to highlight the profound effect of fluid viscosity on velocity profile and fracture permeability. This study demonstrates the applicability of XMT imaging and CFD as powerful tools for characterizing the hydraulic properties of fractures in a number of applications like geologic carbon sequestration and storage, hydraulic fracturing for shale gas production, and enhanced geothermal systems.

  10. Energy policy in China: implications for global climate change

    Energy Technology Data Exchange (ETDEWEB)

    ZhongXiang Zhang [University of Groningen, Groningen (Netherlands)

    1998-12-31

    This is the first systematic and comprehensive analysis of the economic implications of carbon abatement for the Chinese economy. It evaluates the economics of climate change and provides national, cost-effective policies for climate change. The book consists of three main parts, firstly, an analysis of the Chinese energy system to increase awareness of the implications of this sector for China`s future carbon dioxide emissions, secondly, a macroeconomic analysis of carbon dioxide emissions limits using a newly-developed computable general equilibrium model of the Chinese economy; and finally, a cost-effective analysis of carbon abatement options by means of a technology-oriented dynamic optimization model.

  11. Hydrothermal alteration and permeability changes in granitic intrusions related to Sn-W deposits : case study of Panasqueira (Portugal)

    Science.gov (United States)

    Launay, Gaetan; Sizaret, Stanislas; Guillou-Frottier, Laurent; Gloaguen, Eric; Melleton, Jérémie; Pichavant, Michel; Champallier, Rémi; Pinto, Filipe

    2017-04-01

    The Panasqueira Sn-W deposit occurs as a dense network of flat wolframite and cassiterite-bearing quartz veins concentrated in the vicinity of a hidden greisen cupola, and to a lesser extent as disseminated cassiterites in the greisen. Previous studies (Thadeu 1951; 1979) have suggested that the Panasqueira deposit is genetically related to magmatic activity for which the most part is unexposed, and being only represented by the greisen cupola. Hydrothermal fluid circulation during the final stages of granite crystallisation has probably led to the greisenisation of the cupola followed by the deposition of the mineralization in the veins system. Mineral replacement reactions that occurred during the greisenisation could affect rock properties (porosity, density and permeability) which control fluid circulation in the granite. This study aims to investigate effects of greisenisation reactions on the dynamic (time varying) permeability that ultimately leads to fluid circulation in the greisen cupola. To do so, petrological study and experimental determinations of hydrodynamic features (porosity and permeability) for different granite alteration levels and petrographic types (unaltered granite to greisen) are combined and then integrated in coupled numerical models of fluid circulation around the granitic intrusion. Greisen occurs in the apical part of the granitic body and results in the pervasive alteration of the granite along the granite-schist contact. This greisen consists mainly of quartz and muscovite formed by the replacement of feldspars and bleaching of biotites of the initial granite. Otherwise, greisen is generally vuggy which suggests a porosity increase of the granite during hydrothermal alteration processes. This porosity increase has a positive effect on the permeability of the granitic system. Indeed, experimental measurements of permeability with the Paterson press indicate that the initial granite is impermeable (10-20 m2) whereas the greisen is

  12. Alteration behavior of bentonite barrier of radioactive waste disposal by alkaline solutions. Part 1. Permeability change of compacted bentonite immersed in alkaline solutions

    International Nuclear Information System (INIS)

    Yokoyama, Shingo; Nakamura, Kunihiko

    2010-01-01

    Permeability tests using the compacted bentonites and alkaline solutions were carried out to estimate of alteration behavior and the change of permeability during the alteration reaction. The permeability tests of the compacted bentonites were carried out at 23degC for one week after they were immersed in alkaline solution at 60degC for four weeks (immersing test). After permeability tests, the compacted bentonites were repeatedly tested as the same procedure (i.e. repetition of permeability test and immersing test) at 11 cycles. The compacted bentonites with initial dry density of 1.6 Mg/m 3 were reacted with the different type of the alkaline solutions (deionized water, NaOH (pH=12 and 14), KOH (pH=12 and 14) and Ca(OH) 2 (pH=12)) in each experiments. In the case of deionized water and alkaline solutions of pH12, the mineral compositions of altered bentonite were similar to original bentonite while the exchangeable cations of altered bentonites were changed. No changes of the mineralogical features of montmorillonite in altered bentonites (i.e. illitization, baideritization and increasing of layer charge) were observed in the case of deionized water, pH12-NaOH and pH12-Ca(OH) 2 . The montmorillonite was changed to the illite/smectite interstratified mineral containing about 40% illite like component during the reaction with pH12-KOH. In the case of alkaline solutions with pH14, the component minerals of bentonite (e.g. montmorillonite, quartz and clinoptilolite) were dissolved, consequently secondly minerals (e.g. analcime and phillipsite) were crystallized during experiments. Furthermore, the mineralogical features of montmorillonite were changed as illitization (pH14-KOH), beidellitization (pH14-NaOH and pH14-KOH) and increasing of layer charge (pH14-NaOH and pH14-KOH). No increasing of permeability were observed during the experiment using pH12-NaOH and pH12-Ca(OH) 2 as well as the case of deionized water. In the case of pH12-KOH, the permeability continually

  13. Effect of permeability enhancers on paracellular permeability of acyclovir.

    Science.gov (United States)

    Ates, Muge; Kaynak, Mustafa Sinan; Sahin, Selma

    2016-06-01

    According to Biopharmaceutics Classification System (BCS), acyclovir is a class III (high solubility, low permeability) compound, and it is transported through paracellular route by passive diffusion. The aim of this study was to investigate the effect of various pharmaceutical excipients on the intestinal permeability of acyclovir. The single-pass in-situ intestinal perfusion (SPIP) method was used to estimate the permeability values of acyclovir and metoprolol across different intestinal segments (jejunum, ileum and colon). Permeability coefficient (Peff ) of acyclovir was determined in the absence and presence of a permeation enhancer such as dimethyl β-cyclodextrin (DM-β-CD), sodium lauryl sulfate (SLS), sodium caprate (Cap-Na) and chitosan chloride. All enhancers increased the permeability of paracellularly transported acyclovir. Although Cap-Na has the highest permeability-enhancing effect in all segments, permeation-enhancing effect of chitosan and SLS was only significant in ileum. On the other hand, DM-β-CD slightly decreased the permeability in all intestinal segments. These findings have potential implication concerning the enhancement of absorption of paracellularly transported compounds with limited oral bioavailability. In the case of acyclovir, Cap-Na either alone or in combination with SLS or chitosan has the potential to improve its absorption and bioavailability and has yet to be explored. © 2016 Royal Pharmaceutical Society.

  14. Climate change: Implications for water and ecological resources

    International Nuclear Information System (INIS)

    Wall, G.; Sanderson, M.

    1990-01-01

    A conference was held to discuss the implications of climate change on water and ecological resources. The meeting consisted of a number of plenary sessions, luncheon speeches, an open forum, and five workshops. Presentations concerned regional and global issues, climate modelling, international aspects of climate change, water resources supply and demand, wetlands, wildlife and fisheries, agriculture and forests, and conservation strategies. Separate abstracts have been prepared for 32 presentations from the conference

  15. Response of exfoliated human buccal epithelium cells to combined gamma radiation, microwaves, and magnetic field exposure estimated by changes in chromatin condensation and cell membrane permeability

    Directory of Open Access Journals (Sweden)

    K. А. Kuznetsov

    2016-11-01

    Full Text Available Modulation of the biological effects produced by ionizing radiation (IR using microwave and magnetic fields has important theoretical and practical applications. Response of human buccal epithelium cells to different physical agents (single and combined exposure to 0.5–5 Gy γ-radiation (60Co; microwaves with the frequency of 36.64 GHz and power densities of 0.1 and 1 W/m2, and static magnetic field with the intensity of 25 mT has been investigated. The stress response of the cells was evaluated by counting heterochromatin granules quantity (HGQ in the cell nuclei stained with orcein. Membrane permeability was assessed by the percentage of cells stained with indigocarmine (cells with damaged membrane. The increase of heterochromatin granules quantity (HGQ, i.e. chromatin condensation was detected at the doses of 2 Gy and higher. Changes in the cell membrane permeability to indigocarmine expressed the threshold effect. Membrane permeability reached the threshold at the doses of 2–3 Gy for the cells of different donors and did not change with the increase of the dose of γ-radiation. Cells obtained from different donors revealed some individual peculiarities in their reaction to γ-radiation. The static magnetic field and microwaves applied before or after γ-radiation decreased its impact, as revealed by means of HGQ assessment.

  16. Comparative study between chemostat and batch reactors to quantify membrane permeability changes on bacteria exposed to silver nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Anaya, Nelson M.; Faghihzadeh, Fatemeh [Department of Civil and Environmental Engineering, University of Rhode Island, 1 Lippitt Rd., Bliss Hall 203, Kingston, RI 02881 (United States); Ganji, Nasim; Bothun, Geoff [Department of Chemical Engineering, University of Rhode Island, 16 Greenhouse Rd., Crawford Hall, Kingston, RI 02881 (United States); Oyanedel-Craver, Vinka, E-mail: craver@uri.edu [Department of Civil and Environmental Engineering, University of Rhode Island, 1 Lippitt Rd., Bliss Hall 203, Kingston, RI 02881 (United States)

    2016-09-15

    Continuous and batch reactors were used to assess the effect of the exposure of casein-coated silver nanoparticles (AgNPs) on Escherichia coli (E. coli). Additionally, E. coli membrane extracts, membrane permeability and Langmuir film balance assays were used to determine integrity and changes in lipid composition in response to AgNPs exposure. Results showed that batch conditions were not appropriate for the tests due to the production of exopolymeric substances (EPS) during the growth phase. After 5 h of contact between AgNPs and the used growth media containing EPS, the nanoparticles increased in size from 86 nm to 282 nm reducing the stability and thus limiting cell-nanoparticle interactions. AgNPs reduced E. coli growth by 20% at 1 mg/L, in terms of Optical Density 670 (OD670), while no effect was detected at 15 mg/L. At 50 mg/L of AgNPs was not possible to perform the test due to aggregation and sedimentation of the nanoparticles. Membrane extract assays showed that at 1 mg/L AgNPs had a greater change in area (− 4.4cm{sup 2}) on bacteria compared to 15 mg/L (− 4.0cm{sup 2}). This area increment suggested that membrane disruption caused by AgNPs had a stabilizing/rigidifying effect where the cells responded by shifting their lipid composition to more unsaturated lipids to counteract membrane rigidification. In chemostats, the constant inflow of fresh media and aeration resulted in less AgNPs aggregation, thus increased the AgNPs-bacteria interactions, in comparison to batch conditions. AgNPs at 1 mg/L, 15 mg/L, and 50 mg/L inhibited the growth (OD670 reduction) by 0%, 11% and 16.3%, respectively. Membrane extracts exposed to 1 mg/L, 15 mg/L, and 50 mg/L of AgNPs required greater changes in area by − 0.5 cm{sup 2}, 2.7 cm{sup 2} and 3.6 cm{sup 2}, respectively, indicating that the bacterial membranes were disrupted and bacteria responded by synthesizing lipids that stabilize or strengthen membranes. This study showed that the chemostat is more

  17. [Analysis of aberration changes of the corneal anterior surface following discontinued use of rigid gas permeable contact lenses].

    Science.gov (United States)

    Yu, Qing; Wu, Jiang-xiu; Zhang, He-ning; Ye, Sheng; Dong, Shi-qi; Zhang, Chen-hao

    2011-04-01

    The present study used a corneal topographic device to record aberrations on the anterior surface of the cornea at different time-points prior to wearing and following discontinued use of rigid gas permeable (RGP) contact lenses. The effect of wearing RGPCL on the anterior surface of the cornea was discussed to provide guidance for clinical refractive error correction. The study objects were 60 eyes from 30 patients. All patients underwent identical examination procedures prior to lens use, as well as afterwards, including slit-lamp examination, non-contact tonometer measurement, computer optometry & corneal curvature measurement, subjective refraction test, and corneal topography analysis. The patients wore contact lenses every day for 1 month and then discontinued. Corneal topographies were recorded at certain time points of 30 min, 1 day, 3 days, 1 week, and 2 weeks following use. Total corneal aberration at each time point following discontinued use of RGP contact lenses was less than the time point prior to use. Detailed results are as follows; root mean square (RMS) (pre) = (1.438 ± 0.328), RMS (30 min) = (1.076 ± 0.355), RMS (1 day) = (1.362 ± 0.402), RMS (3 day) = (1.373 ± 0.398), RMS (7 day) = (1.387 ± 0.415), and RMS (14 day) = (1.448 ± 0.423). Results showed that at 30 minutes after discontinued use of RGP contact lenses, almost all 2(nd)- and 3(rd)-order aberrations were altered. Quadrafoil Z10 and spherical Z12 of the 4(th)-order were also changed. Alterations to Z5, Z6, and Z12 at 1 day after discontinued use were significant compared with the time period prior to RGP use: Z5 and Z6 decreased, and Z12 increased slightly (F = 2.869 ∼ 5.549, P = 0.001 ∼ 0.042). Z5 and Z6 remained decreased at 3 days after discontinued use, but Z9 and Z10 continued to increase and Z12 returned to levels prior to RGP use (P > 0.05). At 2 weeks after discontinued use, all aberrations were not significantly different from the values prior to use (P > 0.05). The

  18. Relative Permeability of Fractured Rock

    Energy Technology Data Exchange (ETDEWEB)

    Mark D. Habana

    2002-06-30

    Contemporary understanding of multiphase flow through fractures is limited. Different studies using synthetic fractures and various fluids have yielded different relative permeability-saturation relations. This study aimed to extend the understanding of multiphase flow by conducting nitrogen-water relative permeability experiments on a naturally-fractured rock from The Geysers geothermal field. The steady-state approach was used. However, steady state was achieved only at the endpoint saturations. Several difficulties were encountered that are attributed to phase interference and changes in fracture aperture and surface roughness, along with fracture propagation/initiation. Absolute permeabilities were determined using nitrogen and water. The permeability values obtained change with the number of load cycles. Determining the absolute permeability of a core is especially important in a fractured rock. The rock may change as asperities are destroyed and fractures propagate or st rain harden as the net stresses vary. Pressure spikes occurred in water a solute permeability experiments. Conceptual models of an elastic fracture network can explain the pressure spike behavior. At the endpoint saturations the water relative permeabilities obtained are much less than the nitrogen gas relative permeabilities. Saturations were determined by weighing and by resistivity calculations. The resistivity-saturation relationship developed for the core gave saturation values that differ by 5% from the value determined by weighing. Further work is required to complete the relative permeability curve. The steady-state experimental approach encountered difficulties due to phase interference and fracture change. Steady state may not be reached until an impractical length of time. Thus, unsteady-state methods should be pursued. In unsteady-state experiments the challenge will be in quantifying rock fracture change in addition to fluid flow changes.

  19. Population Shift between the Open and Closed States Changes the Water Permeability of an Aquaporin Z Mutant

    DEFF Research Database (Denmark)

    Xin, Lin; Helix Nielsen, Claus; Su, Haibin

    2012-01-01

    gate in the triple mutant with R189 as the primary steric gate in both mutant and WT AqpZ. The double gates (R189 and W43-F183) result in a high population of the closed conformation in the mutant. Occasionally an open state, with diffusive water permeability very close to that of WT AqpZ, was observed...... be modulated and may further point to how aquaporin function can be optimized for biomimetic membrane applications....

  20. Developmental changes of the sensitivity of cardiac and liver mitochondrial permeability transition pore to calcium load and oxidative stress

    Czech Academy of Sciences Publication Activity Database

    Drahota, Zdeněk; Milerová, Marie; Endlicher, R.; Rychtrmoc, D.; Červinková, Z.; Ošťádal, Bohuslav

    2012-01-01

    Roč. 61, Suppl.1 (2012), S165-S172 ISSN 0862-8408 R&D Projects: GA MŠk(CZ) LL1204; GA ČR(CZ) GAP303/12/1162 Institutional support: RVO:67985823 Keywords : mitochondrial permeability transition pore * cardiac mitochondria * liver mitochondria * oxidative stress * calcium load * rat Subject RIV: ED - Physiology Impact factor: 1.531, year: 2012

  1. Changes in intestinal tight junction permeability associated with industrial food additives explain the rising incidence of autoimmune disease.

    Science.gov (United States)

    Lerner, Aaron; Matthias, Torsten

    2015-06-01

    The incidence of autoimmune diseases is increasing along with the expansion of industrial food processing and food additive consumption. The intestinal epithelial barrier, with its intercellular tight junction, controls the equilibrium between tolerance and immunity to non-self-antigens. As a result, particular attention is being placed on the role of tight junction dysfunction in the pathogenesis of AD. Tight junction leakage is enhanced by many luminal components, commonly used industrial food additives being some of them. Glucose, salt, emulsifiers, organic solvents, gluten, microbial transglutaminase, and nanoparticles are extensively and increasingly used by the food industry, claim the manufacturers, to improve the qualities of food. However, all of the aforementioned additives increase intestinal permeability by breaching the integrity of tight junction paracellular transfer. In fact, tight junction dysfunction is common in multiple autoimmune diseases and the central part played by the tight junction in autoimmune diseases pathogenesis is extensively described. It is hypothesized that commonly used industrial food additives abrogate human epithelial barrier function, thus, increasing intestinal permeability through the opened tight junction, resulting in entry of foreign immunogenic antigens and activation of the autoimmune cascade. Future research on food additives exposure-intestinal permeability-autoimmunity interplay will enhance our knowledge of the common mechanisms associated with autoimmune progression. Copyright © 2015. Published by Elsevier B.V.

  2. Climate change and energy: The implications for the Spanish case

    International Nuclear Information System (INIS)

    Perez Arriaga, J. I.

    2007-01-01

    This paper examines the mutual implications between the climate change problem and the actual energy-at-a-crossroads situation of the unsustainable world energy model. The implications for the Spanish case are studied as a case example. The paper provides a brief review of the scientific evidence on climate change, analyzes the causes of the present energy dilemma and characterizes the problem to be addressed. The principal challenge for the future climate regime is to identify the nature and level of commitment that will provide sufficient incentives for all countries, with such a diversity of interests. The paper also exposes the most plausible framework for the future climate regime, the basic components of such a regime, the role to be played by the major stake holders and some guidelines for future negotiations. (Author)

  3. Progressive Climate Change on Titan: Implications for Habitability

    Science.gov (United States)

    Moore, J. M.; A. D. Howard

    2014-01-01

    Titan's landscape is profoundly shaped by its atmosphere and comparable in magnitude perhaps with only the Earth and Mars amongst the worlds of the Solar System. Like the Earth, climate dictates the intensity and relative roles of fluvial and aeolian activity from place to place and over geologic time. Thus Titan's landscape is the record of climate change. We have investigated three broad classes of Titan climate evolution hypotheses (Steady State, Progressive, and Cyclic), regulated by the role, sources, and availability of methane. We favor the Progressive hypotheses, which we will outline here, then discuss their implication for habitability.

  4. Editorial Changes and Item Performance: Implications for Calibration and Pretesting

    Directory of Open Access Journals (Sweden)

    Heather Stoffel

    2014-11-01

    Full Text Available Previous research on the impact of text and formatting changes on test-item performance has produced mixed results. This matter is important because it is generally acknowledged that any change to an item requires that it be recalibrated. The present study investigated the effects of seven classes of stylistic changes on item difficulty, discrimination, and response time for a subset of 65 items that make up a standardized test for physician licensure completed by 31,918 examinees in 2012. One of two versions of each item (original or revised was randomly assigned to examinees such that each examinee saw only two experimental items, with each item being administered to approximately 480 examinees. The stylistic changes had little or no effect on item difficulty or discrimination; however, one class of edits -' changing an item from an open lead-in (incomplete statement to a closed lead-in (direct question -' did result in slightly longer response times. Data for nonnative speakers of English were analyzed separately with nearly identical results. These findings have implications for the conventional practice of repretesting (or recalibrating items that have been subjected to minor editorial changes.

  5. Tertiary Institutions in Ghana Curriculum Coverage on Climate Change: Implications for Climate Change Awareness

    Science.gov (United States)

    Boateng, C. A.

    2015-01-01

    Global problems such as climate change, which have deeper implications for survival of mankind on this planet, needs to be given wider attention in the quest for knowledge. It is expected that, improved knowledge derived from curriculum coverage may promote greater public awareness of such important global issue. This research aims at examining…

  6. REMOVAL OF ADDED NITRATE IN THE SINGLE, BINARY, AND TERNARY SYSTEMS OF COTTON BURR COMPOST, ZEROVALENT IRON, AND SEDIMENT: IMPLICATIONS FOR GROUNDWATER NITRATE REMEDIATION USING PERMEABLE REACTIVE BARRIERS

    Science.gov (United States)

    Recent research has shown that carbonaceous solid materials and zerovalent iron (Fe0) may potentially be used as media in permeable reactive barriers (PRBs) to degrade groundwater nitrate via heterotrophic denitrification in the solid carbon system, and via abiotic reduction and ...

  7. Assessing Political Dynamics in Contemporary Malaysia: Implications for Democratic Change

    Directory of Open Access Journals (Sweden)

    Surain Subramaniam

    2012-01-01

    Full Text Available This article examines political dynamics in Malaysia and assesses the prospects for change in the direction of greater political liberalization. It focuses on the 12th General Election of 2008 and its implications for opportunities and challenges for liberal democratic change in Malaysia. It discusses the role of the internet-based new media in shaping an emerging public sphere, and some factors affecting the changing role of non-Malay voters in the political process. This article argues that democratization in Malaysia is already occurring, albeit at a gradual pace; it is being pushed by the new political forces of civil society actors, newly empowered opposition parties, and the internet-based media. The boundaries of this emerging democratic space is simultaneously being shaped and contested by the political competition between status-quo and reformist forces in this society. Some institutional changes have expanded the parameters of democratic space, although the entrenched dominant institutions of the ruling regime continue to wield sufficient amounts of institutional capacity to subvert any consolidation of these democratic changes for now.

  8. Developments in permeable and low permeability barriers

    International Nuclear Information System (INIS)

    Jefferis, S.A.; Norris, G.H.; Thomas, A.O.

    1997-01-01

    The concept of the reactive treatment zone whereby pollutants are attenuated as they move along a pathway in the ground has enabled a re-thinking of many of the concepts of containment. In particular it offers the potential for the control of the flux from a contaminated area by controlling the contaminant concentration in the pathway(s) as well as or instead of using a low permeability barrier. The paper outlines the basic concepts of the reactive treatment zone and the use of permeable and low permeability reactive systems. The paper then gives a case history of the installation of a permeable barrier using an in-situ reaction chamber

  9. Expressions of tight junction proteins Occludin and Claudin-1 are under the circadian control in the mouse large intestine: implications in intestinal permeability and susceptibility to colitis.

    Directory of Open Access Journals (Sweden)

    Oh-oka Kyoko

    Full Text Available BACKGROUND & AIMS: The circadian clock drives daily rhythms in behavior and physiology. A recent study suggests that intestinal permeability is also under control of the circadian clock. However, the precise mechanisms remain largely unknown. Because intestinal permeability depends on tight junction (TJ that regulates the epithelial paracellular pathway, this study investigated whether the circadian clock regulates the expression levels of TJ proteins in the intestine. METHODS: The expression levels of TJ proteins in the large intestinal epithelium and colonic permeability were analyzed every 4, 6, or 12 hours between wild-type mice and mice with a mutation of a key clock gene Period2 (Per2; mPer2(m/m. In addition, the susceptibility to dextran sodium sulfate (DSS-induced colitis was compared between wild-type mice and mPer2(m/m mice. RESULTS: The mRNA and protein expression levels of Occludin and Claudin-1 exhibited daily variations in the colonic epithelium in wild-type mice, whereas they were constitutively high in mPer2(m/m mice. Colonic permeability in wild-type mice exhibited daily variations, which was inversely associated with the expression levels of Occludin and Claudin-1 proteins, whereas it was constitutively low in mPer2(m/m mice. mPer2(m/m mice were more resistant to the colonic injury induced by DSS than wild-type mice. CONCLUSIONS: Occludin and Claudin-1 expressions in the large intestine are under the circadian control, which is associated with temporal regulation of colonic permeability and also susceptibility to colitis.

  10. Tourism and climate change: socioeconomic implications, mitigation and adaptation measures

    Directory of Open Access Journals (Sweden)

    Utsab Bhattarai

    2015-06-01

    Full Text Available The relationship between tourism and changing climate has been discussed and studied for a relatively long time in tourism research. Over the past 15 years, more focused studies have begun to appear, and especially recently, the issue of adaptation and mitigation has been emphasized as an urgent research need in tourism and climate change studies. This paper is based on the review of selected articles which discuss the several forms of tourism and climate change and provide recommendations for mitigation and adaptation measures. This review paper assesses the impacts of climate change on the popular forms of tourism such as; mountain tourism, wildlife tourism, adventure tourism, sun/sand tourism; last chance tourism, and describes the extent of tourism vulnerabilities and their implications. The paper concludes that the appropriate adaptation and mitigation measures have to be followed to minimize the risk of climate change while trying to save all forms of tourism. The initiative of this article is to present an overview of the existing literature on the relationship between tourism and climate change in order to establish the current state of corporate and institutional responses within the tourism industry and to set out an agenda for future research. The currency of the review is evident given the recent surge in popular discussion on climate change and its effects on tourism, and the appearance of a broad and disparate array of studies on this topic. DOI: http://dx.doi.org/10.3126/ije.v4i2.12664 International Journal of Environment Vol.4(2 2015: 355-373

  11. Effects of components of nucleic acid and extracts of the spleen on radiation-induced changes in the permeability of the capillaries. Studies on mouse skin

    Energy Technology Data Exchange (ETDEWEB)

    Jaenicke, A

    1973-01-01

    Nucleic acids, their components, and Prosplen, an extract of the spleen, were tested in a radiation experiment. The criterion investigated was the sensitivity of radiation-induced changes in the permeability of the capillaries to parenteral drug administration. For a quantitative assessment, Evans blue was used as a colouring matter. In the late X-ray edema, Laevadosin was the only substance with a significant protective action. In the case of measurements immediately after uv exposure, prophylactic and curative RNA injections have a significant effect even after a filtering-out of a large portion of the spectral part absorbed by DNA and nucleobases. A more than average protective effect is found after a curative intravenous injection of Prosplen. In the case of late measurements following unfiltered uv irradiation, a significant depression of the edema was found for all substances tested.

  12. Understanding Heterogeneity and Permeability of Brain Metastases in Murine Models of HER2-Positive Breast Cancer Through Magnetic Resonance Imaging: Implications for Detection and Therapy

    Directory of Open Access Journals (Sweden)

    Donna H. Murrell

    2015-06-01

    Full Text Available OBJECTIVES: Brain metastases due to breast cancer are increasing, and the prognosis is poor. Lack of effective therapy is attributed to heterogeneity of breast cancers and their resulting metastases, as well as impermeability of the blood–brain barrier (BBB, which hinders delivery of therapeutics to the brain. This work investigates three experimental models of HER2+ breast cancer brain metastasis to better understand the inherent heterogeneity of the disease. We use magnetic resonance imaging (MRI to quantify brain metastatic growth and explore its relationship with BBB permeability. DESIGN: Brain metastases due to breast cancer cells (SUM190-BR3, JIMT-1-BR3, or MDA-MB-231-BR-HER2 were imaged at 3 T using balanced steady-state free precession and contrast-enhanced T1-weighted spin echo sequences. The histology and immunohistochemistry corresponding to MRI were also analyzed. RESULTS: There were differences in metastatic tumor appearance by MRI, histology, and immunohistochemistry (Ki67, CD31, CD105 across the three models. The mean volume of an MDA-MB-231-BR-HER2 tumor was significantly larger compared to other models (F2,12 = 5.845, P < .05; interestingly, this model also had a significantly higher proportion of Gd-impermeable tumors (F2,12 = 22.18, P < .0001. Ki67 staining indicated that Gd-impermeable tumors had significantly more proliferative nuclei compared to Gd-permeable tumors (t[24] = 2.389, P < .05 in the MDA-MB-231-BR-HER2 model. CD31 and CD105 staining suggested no difference in new vasculature patterns between permeable and impermeable tumors in any model. CONCLUSION: Significant heterogeneity is present in these models of brain metastases from HER2+ breast cancer. Understanding this heterogeneity, especially as it relates to BBB permeability, is important for improvement in brain metastasis detection and treatment delivery.

  13. Implications for human health of global atmospheric changes

    International Nuclear Information System (INIS)

    Guidotti, T.L.; Last, J.

    1991-01-01

    The possible impacts of the greenhouse effect, ozone depletion and ultraviolet irradiation, acid precipitation, and resulting demographic changes are reviewed, along with the implications of global ecological changes on society and sustainable development. Some manifestations of global warming caused by the greenhouse effect could include more frequently extreme weather conditions, rises in sea level, disruption of ocean currents, and changes in composition and distribution of vegetation. Consequences of these manifestations on human health include an increase in the frequency of droughts and heat waves, migration of disease carrying vectors to other areas, submergence of coastal areas and disruption of water supplies, destruction of tropical species potentially useful for medicinal purposes, and impaired production of crops leading to food shortages. Consequences of stratospheric ozone depletion due to chlorofluorocarbon pollution are thought to be a direct result of increased exposure to ultraviolet light; these consequences include higher risks of non-melanoma skin cancer. The effects of acid precipitation are thought to be primarily ecological and indirect. 61 refs,

  14. Implications of expected climate change in the Mediterranean Region

    Energy Technology Data Exchange (ETDEWEB)

    Jeftic, L. [United Nations Environment Programme, Athens (Greece). Mediterranean Coordinating Unit

    1993-09-01

    A Task Team was established in 1987 with the objective of preparing a Mediterranean regional overview of the implications of climate change for coastal, terrestrial and aquatic ecosystems, as well as for socio-economic structures and activities. The paper presents a summary of the results of the first phase (1987-1989) of the work of the Task Team. Assuming a temperature rise of 1.5{degree}C by the year 2025, land degradation would increase, water resources decline, agricultural production would decline, and terrestrial and aquatic ecosystems could be damaged. Impacts of climatic change when combined with the greater impacts of non-climatic factors (e.g. population increases, development plans) would increase the probability of catastrophic events and hasten their occurrence. Case studies on six sites are to be finalised by the end of 1992. Despite the high quality of the Task Team`s study the impact of its work on national authorities and international bodies was below expectation. A specific regional scenario on climate change in the Mediterranean Basin due to global warming was developed following the Task Team`s recommendation. A summary of the approach and results is presented. 25 refs., 2 figs.

  15. Spillway design implications resulting from changes in rainfall extremes

    International Nuclear Information System (INIS)

    Muzik, I.

    1999-01-01

    A study was conducted in order to determine how serious implications regarding spillway design of small dams would result from changes in flood frequencies and magnitudes, because of changes in rainfall regime in turn brought on by climate change due to carbon dioxide accumulation in the atmosphere. The region selected for study was the central Alberta foothills and adjacent prairie environment. A study watershed, representative of the region, was chosen to assess the present and possible future flood frequency-magnitude relationships. A Monte Carlo simulation method was used in conjunction with rainfall-runoff modelling of the study watershed to generate data for flood frequency analysis of maximum annual flood series corresponding to the present and future climate scenarios. The impact of resulting differences in design floods for small dams on spillway design was investigated using the Prairie Farm Rehabilitation Administration small dam design method. Changes in the mean and standard deviation of rainfall depth of design storms in a region will result in new probability distributions of the maximum annual flood flows. A 25% increase in the mean and standard deviation of design rainfall depth resulted in greater increases of 1:2 and 1:100 flood flows than a 50% increase in the standard deviation alone did. Under scenario 1, the 1:2 flood flows increased more than did the 1:100 flows. Scenario 2 produced opposite results, whereby the 1:100 flows increased more than did the 1:2 flows. It seems that a climate change of the type of scenario 1 would result in a more severe increase in flood flows than scenario 2 would. Retrofitting existing spillways of small dams would in most cases require increasing flow capacities of both operating and auxilliary spillways. 23 refs

  16. Implications of climate change on flow regime affecting Atlantic salmon

    Directory of Open Access Journals (Sweden)

    2007-01-01

    Full Text Available The UKCIP02 climate change scenarios (2070–2100 suggest that the UK climate will become warmer (an overall increase of 2.5–3°C, with temperature increases being greater in the summer and autumn than in the spring and winter seasons. In terms of precipitation, winters are expected to become wetter and summers drier throughout the UK. The effect of changes in the future climate on flow regimes are investigated for the Atlantic salmon, Salmo salar, in a case study in an upland UK river. Using a hydraulic modelling approach, flows simulated across the catchment are assessed in terms of hydraulic characteristics (discharge per metre width, flow depths, flow velocities and Froude number. These, compared with suitable characteristics published in the literature for various life stages of Atlantic salmon, enable assessment of habitat suitability. Climate change factors have been applied to meteorological observations in the Eden catchment (north-west England and effects on the flow regime have been investigated using the SHETRAN hydrological modelling system. High flows are predicted to increase by up to 1.5%; yet, a greater impact is predicted from decreasing low flows (e.g. a Q95 at the outlet of the study catchment may decrease to a Q85 flow. Reliability, Resilience and Vulnerability (RRV analysis provides a statistical indication of the extent and effect of such changes on flows. Results show that future climate will decrease the percentage time the ideal minimum physical habitat requirements will be met. In the case of suitable flow depth for spawning activity at the outlet of the catchment, the percentage time may decrease from 100% under current conditions to 94% in the future. Such changes will have implications for the species under the Habitats Directive and for catchment ecological flow management strategies.

  17. Bentonite Permeability at Elevated Temperature

    Directory of Open Access Journals (Sweden)

    Katherine A. Daniels

    2017-01-01

    Full Text Available Repository designs frequently favour geological disposal of radioactive waste with a backfill material occupying void space around the waste. The backfill material must tolerate the high temperatures produced by decaying radioactive waste to prevent its failure or degradation, leading to increased hydraulic conductivity and reduced sealing performance. The results of four experiments investigating the effect of temperature on the permeability of a bentonite backfill are presented. Bentonite is a clay commonly proposed as the backfill in repository designs because of its high swelling capacity and very low permeability. The experiments were conducted in two sets of purpose-built, temperature controlled apparatus, designed to simulate isotropic pressure and constant volume conditions within the testing range of 4–6 MPa average effective stress. The response of bentonite during thermal loading at temperatures up to 200 °C was investigated, extending the previously considered temperature range. The results provide details of bentonite’s intrinsic permeability, total stress, swelling pressure and porewater pressure during thermal cycles. We find that bentonite’s hydraulic properties are sensitive to thermal loading and the type of imposed boundary condition. However, the permeability change is not large and can mostly be accounted for by water viscosity changes. Thus, under 150 °C, temperature has a minimal impact on bentonite’s hydraulic permeability.

  18. Short-term corneal changes with gas-permeable contact lens wear in keratoconus subjects: a comparison of two fitting approaches.

    Science.gov (United States)

    Romero-Jiménez, Miguel; Santodomingo-Rubido, Jacinto; Flores-Rodríguez, Patricia; González-Méijome, Jose-Manuel

    2015-01-01

    To evaluate changes in anterior corneal topography and higher-order aberrations (HOA) after 14-days of rigid gas-permeable (RGP) contact lens (CL) wear in keratoconus subjects comparing two different fitting approaches. Thirty-one keratoconus subjects (50 eyes) without previous history of CL wear were recruited for the study. Subjects were randomly fitted to either an apical-touch or three-point-touch fitting approach. The lens' back optic zone radius (BOZR) was 0.4mm and 0.1mm flatter than the first definite apical clearance lens, respectively. Differences between the baseline and post-CL wear for steepest, flattest and average corneal power (ACP) readings, central corneal astigmatism (CCA), maximum tangential curvature (KTag), anterior corneal surface asphericity, anterior corneal surface HOA and thinnest corneal thickness measured with Pentacam were compared. A statistically significant flattening was found over time on the flattest and steepest simulated keratometry and ACP in apical-touch group (all p<0.01). A statistically significant reduction in KTag was found in both groups after contact lens wear (all p<0.05). Significant reduction was found over time in CCA (p=0.001) and anterior corneal asphericity in both groups (p<0.001). Thickness at the thinnest corneal point increased significantly after CL wear (p<0.0001). Coma-like and total HOA root mean square (RMS) error were significantly reduced following CL wearing in both fitting approaches (all p<0.05). Short-term rigid gas-permeable CL wear flattens the anterior cornea, increases the thinnest corneal thickness and reduces anterior surface HOA in keratoconus subjects. Apical-touch was associated with greater corneal flattening in comparison to three-point-touch lens wear. Copyright © 2014 Spanish General Council of Optometry. Published by Elsevier Espana. All rights reserved.

  19. Stress concentrations at structural discontinuities in active fault zones in the western United States: Implications for permeability and fluid flow in geothermal fields

    Science.gov (United States)

    Siler, Drew; Hinz, Nicholas H.; Faulds, James E.

    2018-01-01

    Slip can induce concentration of stresses at discontinuities along fault systems. These structural discontinuities, i.e., fault terminations, fault step-overs, intersections, bends, and other fault interaction areas, are known to host fluid flow in ore deposition systems, oil and gas reservoirs, and geothermal systems. We modeled stress transfer associated with slip on faults with Holocene-to-historic slip histories at the Salt Wells and Bradys geothermal systems in western Nevada, United States. Results show discrete locations of stress perturbation within discontinuities along these fault systems. Well field data, surface geothermal manifestations, and subsurface temperature data, each a proxy for modern fluid circulation in the fields, indicate that geothermal fluid flow is focused in these same areas where stresses are most highly perturbed. These results suggest that submeter- to meter-scale slip on these fault systems generates stress perturbations that are sufficiently large to promote slip on an array of secondary structures spanning the footprint of the modern geothermal activity. Slip on these secondary faults and fractures generates permeability through kinematic deformation and allows for transmission of fluids. Still, mineralization is expected to seal permeability along faults and fractures over time scales that are generally shorter than either earthquake recurrence intervals or the estimated life span of geothermal fields. This suggests that though stress perturbations resulting from fault slip are broadly important for defining the location and spatial extent of enhanced permeability at structural discontinuities, continual generation and maintenance of flow conduits throughout these areas are probably dependent on the deformation mechanism(s) affecting individual structures.

  20. Film Permeability Determination Using Static Permeability Cells

    Science.gov (United States)

    The permeability of tarps to soil fumigant pesticides varies depending on the active ingredient chemical: dimethyl disulfide (DMDS), methyl bromide, chloropicrin, or other. The diffusion rate can be represented by the mass transfer coefficient (MTC).

  1. Effect of temperature on sandstone permeability

    DEFF Research Database (Denmark)

    Rosenbrand, Esther; Kjøller, Claus

    Hot water injection in geothermal sandstone aquifers is considered for seasonal energy storage in Denmark. However, an increase in the aquifer temperature might reduce permeability, and thereby increase production costs. An understanding of the factors that control permeability is required in order...... and the Klinkenberg procedure showed the expected correlation between the two measures, however, differences could be around one order of magnitude. In tight gas sandstones, permeability is often sensitive to net stress, which might change due to the pore pressure change in the Klinkenberg procedure. Besides...... affecting the Klinkenberg procedure, the combined effect of slip and changes in permeability would affect production during pressure depletion in tight gas sandstone reservoirs; therefore effects of gas slip and net stress on permeability were combined in a model based on the Klinkenberg equation. A lower...

  2. Suitability of Torrent Permeability Tester to measure air-permeability of covercrete

    Energy Technology Data Exchange (ETDEWEB)

    Andrade, C.; Gonzales-Gasca, C. [Institute of Construction Sciences ' Eduardo Torroja' , Madrid (Spain); Torrent, R. [Portland Cement Institute, (Argentina)

    2000-07-01

    Suitability of the Torrent Permeability Tester (TPT) to measure the permeability of covercrete to air, both in the laboratory and the field, is investigated, and test results obtained in laboratory studies are discussed. The tests performed included the determination of air permeability (TPT method), oxygen permeability (Cembureau method) and capillary suction, rapid chloride permeability test (ASTM C 1202), as well as a one-year carbonation depth test. Concrete specimens of various compositions and curing regimes were used in the tests; the gas-permeability tests were repeated on the same specimens after 28 days, than again at 6 months and 12 months. Test results confirmed the suitability of the TPT as a useful tool in the characterization of the quality the of concrete cover. It was found to be sensitive to changes in concrete quality; repeatable for sensitive properties such as gas permeability ; also, it was found to correlate well with other durability-related properties. 10 refs., 8 tabs., 8 figs.

  3. Some implications of changing patterns of mineral consumption

    Science.gov (United States)

    Menzie, W. David; DeYoung,, John H.; Steblez, Walter G.

    2003-01-01

    DeYoung and Menzie (1999) examined the relations among population, Gross Domestic Product, and mineral consumption (aluminum, cement, copper, and salt) for Japan, Korea, and the United States between 1965 and 1995. They noted the extremely rapid growth of consumption in Korea between 1975 and 1995. Concomitantly, Korea's population growth rate declined. This paper extends that earlier work by examining patterns of consumption of these same commodities in the twenty most populous countries for the period 1970 through 1995. Developed countries, such as France, Germany, Japan, the United Kingdom, and the United States, show patterns of consumption that are stable (cement, copper, and salt) or grow slowly (aluminum). Some developing countries, including China, Thailand, and Turkey, show more rapid growth of consumption, especially of cement, copper, and aluminum. These changing patterns of mineral consumption in developing countries have important implications -- if they continue, there could be major increases in world mineral consumption and major increases in environmental residuals from mineral production and use. If China reaches the level of consumption of copper of developed countries, world consumption could reach levels more than twice that of 1995 (10.5 million tons).

  4. Clinical Implications of Changing Parameters on an Elliptical Trainer.

    Science.gov (United States)

    Kaplan, Yonatan; Nyska, Meir; Palmanovich, Ezequiel; Shanker, Rebecca

    2014-06-01

    Specific weightbearing instructions continue to be a part of routine orthopaedic clinical practice on an injured or postoperative extremity. Researchers and clinicians have struggled to define the best weightbearing strategies to maximize clinical outcomes. To investigate the average percentage body weight (APBW) values, weightbearing distribution percentages (WBDP), and cadence values on the entire foot, hindfoot, and forefoot during changing resistance and incline on an elliptical trainer, as well as to suggest clinical implications. Descriptive laboratory study. An original research study was performed consisting of 30 asymptomatic subjects (mean age, 29.54 ± 12.64 years; range, 21-69 years). The protocol included 3 consecutive tests of changing resistance and incline within a speed range of 70 to 95 steps/min. The SmartStep weightbearing gait analysis system was utilized to measure the values. The APBW values for the entire foot ranged between 70% and 81%, the hindfoot values were between 27% and 57%, and the forefoot values between 42% and 70%. With regard to WBDP, the forefoot remained planted on the pedal (stance phase) 2 to 3 times more as compared with the hindfoot raise in the swing phase. The study findings highlight the fact that elliptical training significantly reduces weightbearing in the hindfoot, forefoot, and entire foot even at higher levels of resistance and incline. Weightbearing on the hindfoot consistently displayed the lowest weightbearing values. Orthopaedic surgeons, now equipped with accurate weightbearing data, may recommend using the elliptical trainer as a weightbearing exercise early on following certain bony or soft tissue pathologies and lower limb surgical procedures.

  5. Family Change and Implications for Family Solidarity and Social Cohesion

    Directory of Open Access Journals (Sweden)

    Ravanera, Zenaida

    2008-01-01

    Full Text Available EnglishSocial cohesion can be viewed in terms of common projects and networks of social relations that characterize families, communities and society. In the past decades, the basis for family cohesion has shifted from organic to mechanical or from breadwinner to collaborative model. As in many Western countries, data on family change in Canada point to a greater flexibility in the entry and exit from relationships, a delay in the timing of family events, and a diversity of family forms. After looking at changes in families and in the family setting of individuals, the paper considers both intra-family cohesion and families as basis for social cohesion. Implications are raised for adults, children and publicp olicy.FrenchLa cohésion sociale peut se voir à travers les projets communs et les réseaux desrelations sociales qui caractérisent les familles, les communautés et les sociétés.La base de cohésion familiale est passée d’organique à mécanique, pour utiliserles termes de Durkheim, ou vers un modèle de collaboration plutôt qu’unepartage asymétrique de tâches. Comme dans d’autres sociétés orientales, lafamille au Canada est devenue plus flexible par rapport aux entrées et sortiesd’unions, il y a un délais dans les événements familiaux, et une variété deformes de familles. Après un regard sur les changements dans les familles etdans la situation familiale des individus, nous considérons la cohésion intrafamilialeet la famille comme base de cohésion sociale. Nous discutons desimpacts sur les adultes, les enfants et la politique publique.

  6. [The climate change policy of the city of São Paulo, Brazil: reflexivity and permeability of the health sector].

    Science.gov (United States)

    Landin, Rubens; Giatti, Leandro Luiz

    2014-10-01

    São Paulo is today an unsustainable city in which social and environmental vulnerabilities are obliged to tackle the uncertainties of climate change. To face up to this situation, in 2009 the city unveiled its Climate Change Policy. The scope of this paper is to analyze how the health sector is preparing to contribute to the implementation of this policy by 2012. Content analysis was the method adopted by examining official documents and conducting semi-structured interviews. In a context of social transformation affected by environmental degradation and socio-environmental consequences there is a need for the cessation of inertia and a demand for new knowledge systems. The outcomes of the study showed a positive intersectorial dialectic relationship, since the research hypothesis was that the health sector would be called upon to back actions on air quality monitoring. Its verification showed a broad scope introducing health promotion and preventive actions as the determinant focus, especially influencing other public policies. Thus, the process under scrutiny acquired reflexivity when evolving with interactive measures breaking with the traditional sectorial and reductionist policy model. It shows an intersectorial perspective based on the importance of issues related to local public health.

  7. Formation and Control of Self-Sealing High Permeability Groundwater Mounds in Impermeable Sediment: Implications for SUDS and Sustainable Pressure Mound Management

    Directory of Open Access Journals (Sweden)

    David D. J. Antia

    2009-10-01

    Full Text Available A groundwater mound (or pressure mound is defined as a volume of fluid dominated by viscous flow contained within a sediment volume where the dominant fluid flow is by Knudsen Diffusion. High permeability self-sealing groundwater mounds can be created as part of a sustainable urban drainage scheme (SUDS using infiltration devices. This study considers how they form, and models their expansion and growth as a function of infiltration device recharge. The mounds grow through lateral macropore propagation within a Dupuit envelope. Excess pressure relief is through propagating vertical surge shafts. These surge shafts can, when they intersect the ground surface result, in high volume overland flow. The study considers that the creation of self-sealing groundwater mounds in matrix supported (clayey sediments (intrinsic permeability = 10–8 to 10–30 m3 m–2 s–1 Pa–1 is a low cost, sustainable method which can be used to dispose of large volumes of storm runoff (<20→2,000 m3/24 hr storm/infiltration device and raise groundwater levels. However, the inappropriate location of pressure mounds can result in repeated seepage and ephemeral spring formation associated with substantial volumes of uncontrolled overland flow. The flow rate and flood volume associated with each overland flow event may be substantially larger than the associated recharge to the pressure mound. In some instances, the volume discharged as overland flow in a few hours may exceed the total storm water recharge to the groundwater mound over the previous three weeks. Macropore modeling is used within the context of a pressure mound poro-elastic fluid expulsion model in order to analyze this phenomena and determine (i how this phenomena can be used to extract large volumes of stored filtered storm water (at high flow rates from within a self-sealing high permeability pressure mound and (ii how self-sealing pressure mounds (created using storm water infiltration can be used to

  8. Effects of Climate Change on Aquatic Invasive Species and Implications for Management and Research (Final Report)

    Science.gov (United States)

    EPA announced the availability of the final report, Effects of Climate Change on Aquatic Invasive Species and Implications for Management and Research . This report reviews available literature on climate-change effects on aquatic invasive species (AIS) and examines sta...

  9. Permeability prediction in chalks

    DEFF Research Database (Denmark)

    Alam, Mohammad Monzurul; Fabricius, Ida Lykke; Prasad, Manika

    2011-01-01

    The velocity of elastic waves is the primary datum available for acquiring information about subsurface characteristics such as lithology and porosity. Cheap and quick (spatial coverage, ease of measurement) information of permeability can be achieved, if sonic velocity is used for permeability p...... significantly using the effective specific surface as the fluid-flow concept. The FZI unit is appropriate for highly permeable sedimentary rocks such as sandstones and limestones that have small surface areas....

  10. Permeability enhancement by shock cooling

    Science.gov (United States)

    Griffiths, Luke; Heap, Michael; Reuschlé, Thierry; Baud, Patrick; Schmittbuhl, Jean

    2015-04-01

    The permeability of an efficient reservoir, e.g. a geothermal reservoir, should be sufficient to permit the circulation of fluids. Generally speaking, permeability decreases over the life cycle of the geothermal system. As a result, is usually necessary to artificially maintain and enhance the natural permeability of these systems. One of the methods of enhancement -- studied here -- is thermal stimulation (injecting cold water at low pressure). This goal of this method is to encourage new thermal cracks within the reservoir host rocks, thereby increasing reservoir permeability. To investigate the development of thermal microcracking in the laboratory we selected two granites: a fine-grained (Garibaldi Grey granite, grain size = 0.5 mm) and a course-grained granite (Lanhelin granite, grain size = 2 mm). Both granites have an initial porosity of about 1%. Our samples were heated to a range of temperatures (100-1000 °C) and were either cooled slowly (1 °C/min) or shock cooled (100 °C/s). A systematic microstructural (2D crack area density, using standard stereological techniques, and 3D BET specific surface area measurements) and rock physical property (porosity, P-wave velocity, uniaxial compressive strength, and permeability) analysis was undertaken to understand the influence of slow and shock cooling on our reservoir granites. Microstructurally, we observe that the 2D crack surface area per unit volume and the specific surface area increase as a result of thermal stressing, and, for the same maximum temperature, crack surface area is higher in the shock cooled samples. This observation is echoed by our rock physical property measurements: we see greater changes for the shock cooled samples. We can conclude that shock cooling is an extremely efficient method of generating thermal microcracks and modifying rock physical properties. Our study highlights that thermal treatments are likely to be an efficient method for the "matrix" permeability enhancement of

  11. Characterisation and monitoring of the Excavation Disturbed Zone (EDZ) in fractured gneisses of the Roselend underground laboratory: permeability measurements, transport property changes and related radon bursts

    Science.gov (United States)

    Wassermann, Jérôme; Sabroux, Jean-Christophe; Richon, Patrick; Pontreau, Sébastien; Guillon, Sophie; Pili, Eric

    2010-05-01

    pressure measurements between an obturated borehole and the tunnel is conducted to monitor the possible modifications of the transport properties of the EDZ due to hydraulical and/or mechanical sollicitations of the nearby Roselend reservoir lake. As radon level is controlled by emanation and transport path through the medium. The observed bursts of radon should be due to changes of the radon transport properties (Trique et al. 1999) of the EDZ. A correlation between the differential pressure variations and radon bursts is clearly observed. Radon bursts seem to be related to overpressure events that take place in the instrumented borehole. Which external sollicitations, hydraulical or mechanical, or both, induce such a behaviour? References Bossart, P., Meier, P. M., Moeri, A., Trick, T., and J.-C. Mayor (2002). Geological and hydraulic characterisation of the excavation disturbed zone in the Opalinus Clay of the Mont Terri Rock Laboratory, Engineering Geology, 66, 19-38. Dezayes, C., and T. Villemin (2002). Etat de la fracturation dans la galerie CEA de Roselend et analyse de la déformation cassante dans le massif du Méraillet, technical report, Lab. de Geodyn. de Chaisnes Alp., Univ. de Savoie, Savoie, France. Jakubick, A. T., and T. Franz (1993). Vacuum testing of the permeability of the excavation damaged zone, Rock Mech. Rock Engng., 26(2), 165-182. Patriarche, D., Pili, E., Adler, P. M., and J.-F. Thovert (2007). Stereological analysis of fractures in the Roselend tunnel and permeability determination, Water Resour. Res., 43, W09421. Richon, P., Perrier, F., Sabroux, J.-C., Trique, M., Ferry, C., Voisin, V., and E. Pili (2004). Spatial and time variations of radon-222 concentration in the atmosphere of a dead-end horizontal tunnel, J. Environ. Radioact., 78, 179-198. Richon, P., Perrier, F., Pili, E., and J.-C. Sabroux (2009). Detectability and significance of the 12hr barometric tide in radon-222 signal, dripwater flow rate, air temperature and carbon dioxide

  12. Damage-induced permeability changes around underground excavations; Endommagement des roches argileuses et permeabilite induite au voisinage d'ouvrages souterrains

    Energy Technology Data Exchange (ETDEWEB)

    Coll, C

    2005-07-15

    The storage of nuclear waste in deep geological formations is now considered more and more as a potential solution. During excavation, a disturbed zone develops in which damaging can be important and which can lead eventually to the failure of the rock. Fluid flow and permeability in the rock mass can be significantly modified producing a possible security risk. Our work consisted in an experimental study of the hydro-mechanical coupling of two argillaceous rocks: Boom clay (Mol, Belgium) and Opalinus clay (Mont-Terri, Switzerland). Triaxial tests were performed in a saturated state to study the permeability evolution of both clays with isotropic and deviatoric stresses. Argillaceous rocks are geo-materials with complex behaviour governed by numerous coupled processes. Strong physico-chemical interactions between the fluid and the solid particles and their very low permeability required the modification of the experimental set up. Moreover, specific procedures were developed to measure permeability and to detect strain localisation in shear bands. We show that for Boom Clay, permeability is not significantly influenced by strain localisation. For Opalinus clay, fracturing can induce an increase of the permeability at low confining pressure. (author)

  13. Damage-induced permeability changes around underground excavations; Endommagement des roches argileuses et permeabilite induite au voisinage d'ouvrages souterrains

    Energy Technology Data Exchange (ETDEWEB)

    Coll, C

    2005-07-15

    The storage of nuclear waste in deep geological formations is now considered more and more as a potential solution. During excavation, a disturbed zone develops in which damaging can be important and which can lead eventually to the failure of the rock. Fluid flow and permeability in the rock mass can be significantly modified producing a possible security risk. Our work consisted in an experimental study of the hydro-mechanical coupling of two argillaceous rocks: Boom clay (Mol, Belgium) and Opalinus clay (Mont-Terri, Switzerland). Triaxial tests were performed in a saturated state to study the permeability evolution of both clays with isotropic and deviatoric stresses. Argillaceous rocks are geo-materials with complex behaviour governed by numerous coupled processes. Strong physico-chemical interactions between the fluid and the solid particles and their very low permeability required the modification of the experimental set up. Moreover, specific procedures were developed to measure permeability and to detect strain localisation in shear bands. We show that for Boom Clay, permeability is not significantly influenced by strain localisation. For Opalinus clay, fracturing can induce an increase of the permeability at low confining pressure. (author)

  14. Socio-economic changes, social capital and implications for climate change in a changing rural Nepal

    DEFF Research Database (Denmark)

    Byg, Anja; Herslund, Lise Byskov

    2016-01-01

    We investigate the use of social capital in the form of social ties in the face of commercialization, urbanization and climate change. While discussions of social capital often focus on whether people possess certain social ties or not our study shows that it is also necessary to consider under...... people have engaged in high-input agriculture, business and paid employment. Diversification of livelihoods has made many people less sensitive to climate change, but this does not translate into decreased vulnerability for the community. Intensive agriculture and lower community cohesion seems...... unsustainable in the long run. Thus, decreased vulnerability at the household level may come at the price of increased vulnerability at higher levels and negative consequences for the wider social–ecological system. Evaluating vulnerability and the role of social ties depends on the unit and sector of analysis...

  15. Flow, origin, and age of groundwater in some deep-lying poorly permeable aquifers in the Netherlands; implications for geological waste disposal

    International Nuclear Information System (INIS)

    Glasbergen, P.

    1985-01-01

    Interest in the hydrological properties of deep strata has been increasing rapidly, especially in relation to waste disposal. For the assessment of the geohydrological stability of the host-rock itself as well as of the migration of contaminants leached from a disposal facility, investigation of the hydrological system is obligatory. Three drillings down to and beyond 500 m through very thick clay layers yielded a number of data providing new information about the hydrological system of deep strata in the Netherlands. Clay samples were taken profiles of water quality vs. depth were established, and groundwater present above and below the deep clay strata was subjected to chemical analyses in isotope determinations. Well tests and slug tests were performed to determine the permeability of the underlying aquifers. Hydraulic conductivity was found to range from 10 -7 to 10 -6 m/s. The estimated age of the deep groundwater below the Oligocene clay is at most about 4 x 10 4 years. An interpretation of the flow system is given on the basis of the relations found between water quality, depth, the conductivity, and the measured water pressures. The present observations and interpretations lead to the conclusion that the groundwater in the investigated deep strata is part of a hydrological cycle whose scale is probably limited and in some places very limited. Studies based on a model support the presented conclusions. 18 references, 9 figures

  16. Maternal antibiotic-induced early changes in microbial colonization selectively modulate colonic permeability and inducible heat shock proteins, and digesta concentrations of alkaline phosphatase and TLR-stimulants in swine offspring.

    Directory of Open Access Journals (Sweden)

    Marie-Edith Arnal

    Full Text Available Elevated intake of high energy diets is a risk factor for the development of metabolic diseases and obesity. High fat diets cause alterations in colonic microbiota composition and increase gut permeability to bacterial lipopolysaccharide, and subsequent low-grade chronic inflammation in mice. Chronic inflammatory bowel diseases are increasing worldwide and may involve alterations in microbiota-host dialog. Metabolic disorders appearing in later life are also suspected to reflect changes in early programming. However, how the latter affects the colon remains poorly studied. Here, we hypothesized that various components of colonic physiology, including permeability, ion exchange and protective inducible heat shock proteins (HSP are influenced in the short- and long-terms by early disturbances in microbial colonization. The hypothesis was tested in a swine model. Offspring were born to control mothers (n = 12 or mothers treated with the antibiotic (ATB amoxicillin around parturition (n = 11. Offspring were slaughtered between 14 and 42 days of age to study short-term effects. For long-term effects, young adult offspring from the same litters consumed a normal or a palm oil-enriched diet for 4 weeks between 140 and 169 days of age. ATB treatment transiently modified maternal fecal microbiota although the minor differences observed for offspring colonic microbiota were nonsignificant. In the short-term, consistently higher HSP27 and HSP70 levels and transiently increased horseradish peroxidase permeability in ATB offspring colon were observed. Importantly, long-term consequences included reduced colonic horseradish peroxidase permeability, and increased colonic digesta alkaline phosphatase (AP and TLR2- and TLR4-stimulant concentrations in rectal digesta in adult ATB offspring. Inducible HSP27 and HSP70 did not change. Interactions between early ATB treatment and later diet were noted for paracellular permeability and concentrations of colonic

  17. Crustal permeability: Introduction to the special issue

    Science.gov (United States)

    Ingebritsen, Steven E.; Gleeson, Tom

    2015-01-01

    The topic of crustal permeability is of broad interest in light of the controlling effect of permeability on diverse geologic processes and also timely in light of the practical challenges associated with emerging technologies such as hydraulic fracturing for oil and gas production (‘fracking’), enhanced geothermal systems, and geologic carbon sequestration. This special issue of Geofluids is also motivated by the historical dichotomy between the hydrogeologic concept of permeability as a static material property that exerts control on fluid flow and the perspective of economic geologists, geophysicists, and crustal petrologists who have long recognized permeability as a dynamic parameter that changes in response to tectonism, fluid production, and geochemical reactions. Issues associated with fracking, enhanced geothermal systems, and geologic carbon sequestration have already begun to promote a constructive dialog between the static and dynamic views of permeability, and here we have made a conscious effort to include both viewpoints. This special issue also focuses on the quantification of permeability, encompassing both direct measurement of permeability in the uppermost crust and inferential permeability estimates, mainly for the deeper crust.

  18. Permeability During Magma Expansion and Compaction

    Science.gov (United States)

    Gonnermann, Helge. M.; Giachetti, Thomas; Fliedner, Céline; Nguyen, Chinh T.; Houghton, Bruce F.; Crozier, Joshua A.; Carey, Rebecca J.

    2017-12-01

    Plinian lapilli from the 1060 Common Era Glass Mountain rhyolitic eruption of Medicine Lake Volcano, California, were collected and analyzed for vesicularity and permeability. A subset of the samples were deformed at a temperature of 975°, under shear and normal stress, and postdeformation porosities and permeabilities were measured. Almost all undeformed samples fall within a narrow range of vesicularity (0.7-0.9), encompassing permeabilities between approximately 10-15 m2 and 10-10 m2. A percolation threshold of approximately 0.7 is required to fit the data by a power law, whereas a percolation threshold of approximately 0.5 is estimated by fitting connected and total vesicularity using percolation modeling. The Glass Mountain samples completely overlap with a range of explosively erupted silicic samples, and it remains unclear whether the erupting magmas became permeable at porosities of approximately 0.7 or at lower values. Sample deformation resulted in compaction and vesicle connectivity either increased or decreased. At small strains permeability of some samples increased, but at higher strains permeability decreased. Samples remain permeable down to vesicularities of less than 0.2, consistent with a potential hysteresis in permeability-porosity between expansion (vesiculation) and compaction (outgassing). We attribute this to retention of vesicle interconnectivity, albeit at reduced vesicle size, as well as bubble coalescence during shear deformation. We provide an equation that approximates the change in permeability during compaction. Based on a comparison with data from effusively erupted silicic samples, we propose that this equation can be used to model the change in permeability during compaction of effusively erupting magmas.

  19. Understanding and managing organizational change: implications for public health management.

    Science.gov (United States)

    Thompson, Jon M

    2010-01-01

    Managing organizational change has become a significant responsibility of managers. Managing the change process within public health organizations is important because appropriately and systematically managing change is linked to improved organizational performance. However, change is difficult and the change process poses formidable challenges for managers. Managers themselves face increased pressure to respond to environmental influences and provide the necessary leadership to their organizations in the change process. In fact, managing organizational change has become a key competency for healthcare managers. This article addresses the important topic of organizational change in public health organizations. It provides a conceptual foundation for understanding organizational change and its relationship to healthcare organizational performance, and then discusses the types and nature of change, using some examples and evidence from those organizations that have successfully managed change. A framework for guiding public health managers in the change management process is provided. The article concludes with suggested management competencies to establish a change-oriented organization with the culture and capacity for change.

  20. Global climate change: Implications, challenges, and mitigation measures

    International Nuclear Information System (INIS)

    Majumdar, S.K.

    1992-01-01

    This book presents a perspective of the potential problem of global climate change induced by human activity. The editors have presented viewpoints of experts (advocates and skeptics) representing the issues of climate change. Possible results from long-term global change discussed in this book include mass migrations of plants and animals; changes in crop yields; flood and drought; and economic, political, and cultural changes. The text contains 20 chapters on the impact of global climate change and 10 chapters on the mitigation of effects and policy development

  1. Regional to global changes in drought and implications for future changes under global warming

    Science.gov (United States)

    Sheffield, J.; Wood, E. F.; Kam, J.

    2012-12-01

    Drought can have large impacts on multiple sectors, including agriculture, water resources, ecosystems, transport, industry and tourism. In extreme cases, regional drought can lead to food insecurity and famine, and in intensive agricultural regions, extend to global economic impacts in a connected world. Recent droughts globally have been severe and costly but whether they are becoming more frequent and severe, and the attribution of this, is a key question. Observational evidence at large scales, such as satellite remote sensing are often subject to short-term records and inhomogeneities, and ground based data are sparse in many regions. Reliance on model output is also subject to error and simplifications in the model physics that can, for example, amplify the impact of global warming on drought. This presentation will show the observational and model evidence for changes in drought, with a focus on the interplay between precipitation and atmospheric evaporative demand and its impact on the terrestrial water cycle and drought. We discuss the fidelity of climate models to reproduce our best estimates of drought variability and its drivers historically, and the implications of this on uncertainties in future projections of drought from CMIP5 models, and how this has changed since CMIP3.

  2. Climate change and tourism: Implications for South Africa | Steyn ...

    African Journals Online (AJOL)

    African Journal for Physical Activity and Health Sciences ... Global warming is a much debated issue. ... scientists nevertheless agree that the world's climate is changing and that these changes will have a profound effect on human activities.

  3. Organizational change theory: implications for health promotion practice.

    Science.gov (United States)

    Batras, Dimitri; Duff, Cameron; Smith, Ben J

    2016-03-01

    Sophisticated understandings of organizational dynamics and processes of organizational change are crucial for the development and success of health promotion initiatives. Theory has a valuable contribution to make in understanding organizational change, for identifying influential factors that should be the focus of change efforts and for selecting the strategies that can be applied to promote change. This article reviews select organizational change models to identify the most pertinent insights for health promotion practitioners. Theoretically derived considerations for practitioners who seek to foster organizational change include the extent to which the initiative is modifiable to fit with the internal context; the amount of time that is allocated to truly institutionalize change; the ability of the agents of change to build short-term success deliberately into their implementation plan; whether or not the shared group experience of action for change is positive or negative and the degree to which agencies that are the intended recipients of change are resourced to focus on internal factors. In reviewing theories of organizational change, the article also addresses strategies for facilitating the adoption of key theoretical insights into the design and implementation of health promotion initiatives in diverse organizational settings. If nothing else, aligning health promotion with organizational change theory promises insights into what it is that health promoters do and the time that it can take to do it effectively. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  4. Soils - Mean Permeability

    Data.gov (United States)

    Kansas Data Access and Support Center — This digital spatial data set provides information on the magnitude and spatial pattern of depth-weighted, mean soil permeability throughout the State of Kansas. The...

  5. Hydrogen permeability through metals

    International Nuclear Information System (INIS)

    Pisarev, A.A.; Tsvetkov, I.V.; Marenkov, E.D.; Yarko, S.S.

    2011-01-01

    The mechanisms of hydrogen permeability through one-layer and multi-layer membranes are considered. The effect of surface roughness, crystal defects, cracks and pores is described. Mathematical description of the processes is given [ru

  6. Permeable pavement study (Edison)

    Data.gov (United States)

    U.S. Environmental Protection Agency — While permeable pavement is increasingly being used to control stormwater runoff, field-based, side-by-side investigations on the effects different pavement types...

  7. Permeability of gypsum samples dehydrated in air

    Science.gov (United States)

    Milsch, Harald; Priegnitz, Mike; Blöcher, Guido

    2011-09-01

    We report on changes in rock permeability induced by devolatilization reactions using gypsum as a reference analog material. Cylindrical samples of natural alabaster were dehydrated in air (dry) for up to 800 h at ambient pressure and temperatures between 378 and 423 K. Subsequently, the reaction kinetics, so induced changes in porosity, and the concurrent evolution of sample permeability were constrained. Weighing the heated samples in predefined time intervals yielded the reaction progress where the stoichiometric mass balance indicated an ultimate and complete dehydration to anhydrite regardless of temperature. Porosity showed to continuously increase with reaction progress from approximately 2% to 30%, whilst the initial bulk volume remained unchanged. Within these limits permeability significantly increased with porosity by almost three orders of magnitude from approximately 7 × 10-19 m2 to 3 × 10-16 m2. We show that - when mechanical and hydraulic feedbacks can be excluded - permeability, reaction progress, and porosity are related unequivocally.

  8. Implications of climate change for Pacific Northwest forest management

    International Nuclear Information System (INIS)

    Wall, G.

    1991-01-01

    A Canada/USA symposium was held to identify potential consequences of global climate change to Pacific Northwest forests; to identify the future role and relative contribution of those forests in the balance of carbon, moisture, and energy exchange of the atmosphere; and to develop recommendations for Pacific Northwest forest management strategies and policy options for responding to global climate change. Papers were presented on such topics as regional climatic change, forest responses and processes, public policy on forests and climatic change, sequestration of atmospheric carbon, forest management, and forest adaptation to climatic change. Separate abstracts have been prepared for 14 papers from this symposium

  9. Performance Implications of Business Model Change: A Case Study

    Directory of Open Access Journals (Sweden)

    Jana Poláková

    2015-01-01

    Full Text Available The paper deals with changes in performance level introduced by the change of business model. The selected case is a small family business undergoing through substantial changes in reflection of structural changes of its markets. The authors used the concept of business model to describe value creation processes within the selected family business and by contrasting the differences between value creation processes before and after the change introduced they prove the role of business model as the performance differentiator. This is illustrated with the use of business model canvas constructed on the basis interviews, observations and document analysis. The two business model canvases allow for explanation of cause-and-effect relationships within the business leading to change in performance. The change in the performance is assessed by financial analysis of the business conducted over the period of 2006–2012 demonstrates changes in performance (comparing development of ROA, ROE and ROS having their lowest levels before the change of business model was introduced, growing after the introduction of the change, as well as the activity indicators with similar developments of the family business. The described case study contributes to the concept of business modeling with the arguments supporting its value as strategic tool facilitating decisions related to value creation within the business.

  10. Implications of climate and land use change: Chapter 4

    Science.gov (United States)

    Hall, Jefferson S.; Murgueitio, Enrique; Calle, Zoraida; Raudsepp-Hearne, Ciara; Stallard, Robert F.; Balvanera, Patricia; Hall, Jefferson S.; Kirn, Vanessa; Yanguas-Fernandez, Estrella

    2015-01-01

    This chapter relates ecosystem services to climate change and land use. The bulk of the chapter focuses on ecosystem services and steepland land use in the humid Neotropics – what is lost with land-cover changed, and what is gained with various types of restoration that are sustainable given private ownership. Many case studies are presented later in the white paper. The USGS contribution relates to climate change and the role of extreme weather events in land-use planning.

  11. Climate Change Effects on Respiratory Health: Implications for Nursing.

    Science.gov (United States)

    George, Maureen; Bruzzese, Jean-Marie; Matura, Lea Ann

    2017-11-01

    Greenhouse gases are driving climate change. This article explores the adverse health effects of climate change on a particularly vulnerable population: children and adults with respiratory conditions. This review provides a general overview of the effects of increasing temperatures, extreme weather, desertification, and flooding on asthma, chronic obstructive lung disease, and respiratory infections. We offer suggestions for future research to better understand climate change hazards, policies to support prevention and mitigation efforts targeting climate change, and clinical actions to reduce individual risk. Climate change produces a number of changes to the natural and built environments that may potentially increase respiratory disease prevalence, morbidity, and mortality. Nurses might consider focusing their research efforts on reducing the effects of greenhouse gases and in directing policy to mitigate the harmful effects of climate change. Nurses can also continue to direct educational and clinical actions to reduce risks for all populations, but most importantly, for our most vulnerable groups. While advancements have been made in understanding the impact of climate change on respiratory health, nurses can play an important role in reducing the deleterious effects of climate change. This will require a multipronged approach of research, policy, and clinical action. © 2017 Sigma Theta Tau International.

  12. Preventing skin cancer through behavior change. Implications for interventions.

    Science.gov (United States)

    Rossi, J S; Blais, L M; Redding, C A; Weinstock, M A

    1995-07-01

    Sun exposure is the only major causative factor for skin cancer for which prevention is feasible. Both individual and community-based interventions have been effective in changing sun exposure knowledge and attitudes but generally have not been effective in changing behaviors. An integrative model of behavior change is described that has been successful in changing behavior across a wide range of health conditions. This model holds promise for developing a rational public health approach to skin cancer prevention based on sound behavioral science.

  13. Ontogenetic Shape Change in the Chicken Brain: Implications for Paleontology.

    Science.gov (United States)

    Kawabe, Soichiro; Matsuda, Seiji; Tsunekawa, Naoki; Endo, Hideki

    2015-01-01

    Paleontologists have investigated brain morphology of extinct birds with little information on post-hatching changes in avian brain morphology. Without the knowledge of ontogenesis, assessing brain morphology in fossil taxa could lead to misinterpretation of the phylogeny or neurosensory development of extinct species. Hence, it is imperative to determine how avian brain morphology changes during post-hatching growth. In this study, chicken brain shape was compared at various developmental stages using three-dimensional (3D) geometric morphometric analysis and the growth rate of brain regions was evaluated to explore post-hatching morphological changes. Microscopic MRI (μMRI) was used to acquire in vivo data from living and post-mortem chicken brains. The telencephalon rotates caudoventrally during growth. This change in shape leads to a relative caudodorsal rotation of the cerebellum and myelencephalon. In addition, all brain regions elongate rostrocaudally and this leads to a more slender brain shape. The growth rates of each brain region were constant and the slopes from the growth formula were parallel. The dominant pattern of ontogenetic shape change corresponded with interspecific shape changes due to increasing brain size. That is, the interspecific and ontogenetic changes in brain shape due to increased size have similar patterns. Although the shape of the brain and each brain region changed considerably, the volume ratio of each brain region did not change. This suggests that the brain can change its shape after completing functional differentiation of the brain regions. Moreover, these results show that consideration of ontogenetic changes in brain shape is necessary for an accurate assessment of brain morphology in paleontological studies.

  14. Ontogenetic Shape Change in the Chicken Brain: Implications for Paleontology.

    Directory of Open Access Journals (Sweden)

    Soichiro Kawabe

    Full Text Available Paleontologists have investigated brain morphology of extinct birds with little information on post-hatching changes in avian brain morphology. Without the knowledge of ontogenesis, assessing brain morphology in fossil taxa could lead to misinterpretation of the phylogeny or neurosensory development of extinct species. Hence, it is imperative to determine how avian brain morphology changes during post-hatching growth. In this study, chicken brain shape was compared at various developmental stages using three-dimensional (3D geometric morphometric analysis and the growth rate of brain regions was evaluated to explore post-hatching morphological changes. Microscopic MRI (μMRI was used to acquire in vivo data from living and post-mortem chicken brains. The telencephalon rotates caudoventrally during growth. This change in shape leads to a relative caudodorsal rotation of the cerebellum and myelencephalon. In addition, all brain regions elongate rostrocaudally and this leads to a more slender brain shape. The growth rates of each brain region were constant and the slopes from the growth formula were parallel. The dominant pattern of ontogenetic shape change corresponded with interspecific shape changes due to increasing brain size. That is, the interspecific and ontogenetic changes in brain shape due to increased size have similar patterns. Although the shape of the brain and each brain region changed considerably, the volume ratio of each brain region did not change. This suggests that the brain can change its shape after completing functional differentiation of the brain regions. Moreover, these results show that consideration of ontogenetic changes in brain shape is necessary for an accurate assessment of brain morphology in paleontological studies.

  15. Land Use Pattern, Climate Change, and Its Implication for Food ...

    African Journals Online (AJOL)

    While Ethiopia has always suffered from climatic variability like droughts and consequently food shortage and famine, climate change is set to make the lives of the poorest even harder. Climate change has the potential to adversely affect net farm revenues of small holders with increasing land fragmentation due to ...

  16. LAND USE PATTERN, CLIMATE CHANGE, AND ITS IMPLICATION ...

    African Journals Online (AJOL)

    Osondu

    2012-01-30

    Jan 30, 2012 ... impacted seriously on Ethiopia's rich biodiversity, crop production ... change in the rural areas of Ethiopia, this paper therefore reviewed ... Key words: Climate change, Land use pattern, and Food security. .... releasing greenhouse gases, and the major driver ... Agricultural systems worldwide over the last.

  17. Effect of Climate Change on the Food Supply System: Implications ...

    African Journals Online (AJOL)

    Climate change has become an issue of great concern in recent years due to its effect on every aspect of life. The ecosystem, agriculture, industry, households and human well-being are all intertwined with climate change issues. The food supply system worldwide has been affected and is also contributing to climate ...

  18. Change Factors requiring agility and implications for IT

    NARCIS (Netherlands)

    van Oosterhout, Marcel; Waarts, Eric; van Hillegersberg, Jos

    2006-01-01

    The current highly dynamic business environment requires businesses to be agile. Business agility is the ability to swiftly and easily change businesses and business processes beyond the normal level of flexibility to effectively manage unpredictable external and internal changes. This study reports

  19. Climate Change and Global Warming: Implications for Sub-Saharan ...

    African Journals Online (AJOL)

    The study reviews the potential threats of climate change in sub-Sahara Africa. It paints a picture of how the major green house gases (GHGs)-CO2, CH4 will grow in the sub-continent before the year 2015. The study also highlights the potential causes of climate change in the sub-continent based on anthropogenic and ...

  20. Permeability Barrier Generation in the Martian Lithosphere

    Science.gov (United States)

    Schools, Joe; Montési, Laurent

    2015-11-01

    Permeability barriers develop when a magma produced in the interior of a planet rises into the cooler lithosphere and crystallizes more rapidly than the lithosphere can deform (Sparks and Parmentier, 1991). Crystallization products may then clog the porous network in which melt is propagating, reducing the permeability to almost zero, i.e., forming a permeability barrier. Subsequent melts cannot cross the barrier. Permeability barriers have been useful to explain variations in crustal thickness at mid-ocean ridges on Earth (Magde et al., 1997; Hebert and Montési, 2011; Montési et al., 2011). We explore here under what conditions permeability barriers may form on Mars.We use the MELTS thermodynamic calculator (Ghiorso and Sack, 1995; Ghiorso et al., 2002; Asimow et al., 2004) in conjunction with estimated Martian mantle compositions (Morgan and Anders, 1979; Wänke and Dreibus, 1994; Lodders and Fegley, 1997; Sanloup et al., 1999; Taylor 2013) to model the formation of permeability barriers in the lithosphere of Mars. In order to represent potential past and present conditions of Mars, we vary the lithospheric thickness, mantle potential temperature (heat flux), oxygen fugacity, and water content.Our results show that permeability layers can develop in the thermal boundary layer of the simulated Martian lithosphere if the mantle potential temperature is higher than ~1500°C. The various Martian mantle compositions yield barriers in the same locations, under matching variable conditions. There is no significant difference in barrier location over the range of accepted Martian oxygen fugacity values. Water content is the most significant influence on barrier development as it reduces the temperature of crystallization, allowing melt to rise further into the lithosphere. Our lower temperature and thicker lithosphere model runs, which are likely the most similar to modern Mars, show no permeability barrier generation. Losing the possibility of having a permeability

  1. Vegetation response to climate change : implications for Canada's conservation lands

    International Nuclear Information System (INIS)

    Scott, D.; Lemieux, C.

    2003-01-01

    Studies have shown that Canada's national parks are vulnerable to the impacts of climate change. A wide range of biophysical climate change impacts could affect the integrity of conservation lands in each region of Canada. This report examines the potential impact of climate change on landscape alterations and vegetation distribution in Canada's wide network of conservation lands. It also presents several ways to integrate climate change into existing conservation policy and adaptation strategies. Canada's conservation lands include provincial parks, migratory bird sanctuaries, national wildlife areas and wildlife protected areas. This is the first study to examine biome changes by applying an equilibrium Global Vegetation Model (GVM) to Canada's network of national park systems. Some of the policy and planning challenges posed by changes in landscape level vegetation were also addressed. The report indicates that in terms of potential changes to the biome classification of Canada's national forests, more northern biomes are projected to decrease. These northern biomes include the tundra, taiga and boreal conifer forests. 56 refs., 8 tabs., 6 figs

  2. Implications of climatic change for tourism and recreation in Ontario

    International Nuclear Information System (INIS)

    Wall, G.; Harrison, R.; Kinnaird, V.; McBoyle, G.; Quinland, C.

    1988-01-01

    Scenarios for climatic change associated with a doubling of atmospheric carbon dioxide were employed in an assessment of the impacts of climate change on tourism and recreation in Ontario. A warmer climate resulting from such change may mean declining lake levels with associated changes in the ecological interest and recreational potential of wetlands, as shown by case studies on two parks near Great Lakes shorelines. In the skiing industry, the length of ski seasons will be reduced in the northern part of the province, but the key holiday periods (when a large portion of total business is conducted) should still fall within the reliable ski season. Further south, the ski season in the South Georgian Bay region could be eliminated. Summer recreational activities are likely to have extended seasons, and the viability of summer recreational enterprises may increase, with associated positive benefits to neighboring communities. 2 refs., 6 figs., 3 tabs

  3. Reading strategy instruction and teacher change: Implications for ...

    African Journals Online (AJOL)

    I report on teacher change in the context of a reading strategy instruction intervention. Reading Strategy Instruction (RSI) was implemented by three teachers, new to the concept, over a period of 15 weeks. ... AJOL African Journals Online.

  4. Radiation induced changes in the airway - anaesthetic implications

    African Journals Online (AJOL)

    Adele

    CASE REPORT. Southern African Journal of Anaesthesia & Analgesia - May 2004. 19. Radiation ... Summary: Radiation induces a variety of changes in the airway that can potentially lead to difficult intubation. ... Mask holding and ventilation is.

  5. Motivation to change in eating disorders: clinical and therapeutic implications.

    Science.gov (United States)

    Casasnovas, C; Fernández-Aranda, F; Granero, R; Krug, I; Jiménez-Murcia, S; Bulik, C M; Vallejo-Ruiloba, J

    2007-11-01

    The aim of this study was to understand the clinical impact of the motivational stage of change on the psychopathology and symptomatology of anorexia nervosa (AN), bulimia nervosa (BN) and eating disorders not otherwise specified (EDNOS). The participants were 218 eating disorder (ED) patients (58 AN, 95 BN and 65 EDNOS), consecutively admitted to our hospital. All patients fulfilled DSM-IV criteria for these disorders. Assessment measures included the Eating Disorders Inventory (EDI), Bulimic Investigation Test Edinburgh (BITE), Beck Depression Inventory (BDI), four analogue scales of motivational stage, as well as a number of other clinical and psychopathological indices. Our results indicated higher motivation for change in BN than in AN and EDNOS patients (p EDNOS (p EDNOS patients are most resistant to change and the younger these patients are, the less likely they are to be motivated to change their disturbed eating behaviour. 2007 John Wiley & Sons, Ltd and Eating Disorders Association

  6. Ontogenetic Shape Change in the Chicken Brain: Implications for Paleontology

    OpenAIRE

    Kawabe, Soichiro; Matsuda, Seiji; Tsunekawa, Naoki; Endo, Hideki

    2015-01-01

    Paleontologists have investigated brain morphology of extinct birds with little information on post-hatching changes in avian brain morphology. Without the knowledge of ontogenesis, assessing brain morphology in fossil taxa could lead to misinterpretation of the phylogeny or neurosensory development of extinct species. Hence, it is imperative to determine how avian brain morphology changes during post-hatching growth. In this study, chicken brain shape was compared at various developmental st...

  7. China: The Impact of Climate Change to 2030. Geopolitical Implications

    Science.gov (United States)

    2009-06-01

    China ranks lower in resilience to climate change than Brazil , Turkey, and Mexico, but higher than India. • China can adapt its administrative...flooding and intensified storm surges, leading to degradation of wetlands, mangroves , and coral reefs. Agricultural growing seasons will lengthen and...dry areas, so both droughts and floods may increase. China ranks lower in resilience to climate change3 than Brazil , Turkey, and Mexico but higher

  8. Oil Regime Change in Iraq. Possible Strategic Implications for OPEC

    International Nuclear Information System (INIS)

    Boon Von Ochssee, T.A.

    2006-06-01

    The potential strategic impact of regime change in Iraq and Iran on OPEC in the long-run is explored. In the first part of the paper short overviews are given of the present international oil market; of US oil import issues and energy policy; of the strategic position of the US in the Persian Gulf and of geopolitical developments in the Persian Gulf at large. Also, attention is paid to the OPEC and the role of a 'new' Iraq. In the second part the game of 'boxed pigs' is used to explore the possible strategic impact of regime change in Iraq and possible regime change in Iran on OPEC. This exploration takes place within four possible futures for the Gulf

  9. The Kidney in Aging: Physiological Changes and Pathological Implications.

    Science.gov (United States)

    Sobamowo, H; Prabhakar, S S

    2017-01-01

    Aging is associated with progressive decline in renal function along with concurrent morphological changes that ultimately lead to glomerulosclerosis. The mechanisms leading to such changes in the kidney with age as well as the basis of controversies that surround the physiological basis vs pathological nature of aging kidney are the focus of this in-depth review. In addition, the renal functional defects of acid-base homeostasis and electrolyte disturbances in elderly and the physiological basis of such disorders are also discussed. © 2017 Elsevier Inc. All rights reserved.

  10. The Futures Wheel: A method for exploring the implications of social-ecological change

    Science.gov (United States)

    D.N. Bengston

    2015-01-01

    Change in social-ecological systems often produces a cascade of unanticipated consequences. Natural resource professionals and other stakeholders need to understand the possible implications of cascading change to prepare for it. The Futures Wheel is a "smart group" method that uses a structured brainstorming process to uncover and evaluate multiple levels of...

  11. Psychological Impact of Women's Name Change at Marriage: Literature Review and Implications for Further Study.

    Science.gov (United States)

    Dralle, Penelope Wasson; Mackiewicz, Kathelynne

    1981-01-01

    Reviewed the published research on the psychological significance of names and name changes. Found little data pertaining to the implications of a woman changing or retaining her surname at marriage. Suggests such research would have relevance for individual personality development, marital and family relationships, and social and cultural…

  12. Changing STM curricula for the information age: Implications for the ...

    African Journals Online (AJOL)

    ... resource economy to knowledge base economy using information and communication technology (ICT) as platform. This calls for a change in every field of life endeavour. Consequently, the current trend in education is on how to utilize the pervasive tools of ICT to improve education at all levels since education has been ...

  13. Implic ations of climate change and deforestation on behavioural ...

    African Journals Online (AJOL)

    Indiscriminate forest exploitation leads to deforestation also, release of CO2 and other pollutants tampers with ozone layer which has been acting as a big umbrella against ultraviolet radiation. This paper discusses effects of climate change and deforestation on physical environment as they affect animal population, ...

  14. Climate Change and Variability: Implications for Household Food ...

    African Journals Online (AJOL)

    These are drought, low annual rainfall, high temperature, and water shortage. The econometric model estimation result revealed the important factors determining household food security. These are household perception of climate change, use of soil and water conservation practices, use of livestock feed management ...

  15. The socio-cultural implications of climate change in Cameroon ...

    African Journals Online (AJOL)

    Climate change impact has remained a serious threat to man and more particularly in the water-stressed environment of north Cameroon where in most cases, man struggles for bare survival by eking out a living from a harsh or hostile climatic environment. In this region, the socio-cultural impacts can be devastating as has ...

  16. Changes in risk factors during adolescence: implications for risk assessment

    NARCIS (Netherlands)

    van der Put, C.E.; Deković, M.; Stams, G.J.J.M.; van der Laan, P.H.; Hoeve, M.; van Amelsfort, L.

    2011-01-01

    This study examined to what extent the significance of both static and dynamic risk factors for recidivism changes in the course of adolescence. For this purpose, file and interview data of 1,396 juveniles charged with a criminal offense were analyzed. This study showed that the impact of almost all

  17. Implications of Demographic Change for the Design of Retirement Programs.

    Science.gov (United States)

    Biggs, John H.

    1994-01-01

    The influences that demographic changes may have on the design of private pension plans in the twenty-first century are examined. Major demographic factors to be considered include the aging of the population, declining mortality rate, potential for an even lower mortality rate, improved health for all ages and especially for older workers, and…

  18. Climate Change and Variability: Implications for Household Food ...

    African Journals Online (AJOL)

    Daniel

    Respondents in focus groups expressed similar views with that of survey respondents and .... were checked using the variance inflation factor (VIF) and Contingency coefficient (CC) test for .... areas of the country, where small changes in rainfall and temperature could cause serious .... Publishing Company. Lai, C. (2007).

  19. Vulnerability of amphibians to climate change: implications for rangeland management

    Science.gov (United States)

    Karen E. Bagne; Deborah M. Finch; Megan M. Friggens

    2011-01-01

    Many amphibian populations have declined drastically in recent years due to a large number of factors including the emerging threat of climate change (Wake 2007). Rangelands provide important habitat for amphibians. In addition to natural wetlands, stock tanks and other artificial water catchments provide habitat for many amphibian species (Euliss et al. 2004).

  20. Reading Strategy Instruction and Teacher Change: Implications for Teacher Training

    Science.gov (United States)

    Klapwijk, Nanda M.

    2012-01-01

    I report on teacher change in the context of a reading strategy instruction intervention. Reading Strategy Instruction (RSI) was implemented by three teachers, new to the concept, over a period of 15 weeks. Observations of these teachers showed that a multitude of factors affect the uptake of RSI as part of everyday teaching practice, and that…

  1. Macroeconomic Implications of Changes in Social Security Rules

    Directory of Open Access Journals (Sweden)

    Bilal Bagis

    2017-02-01

    Full Text Available The Turkish social insurance system has been feverishly debated for years, particularly through its burden on the economy. The most recent reform is an attempt to neutralize the deterioration within the social security system and its effects on the economy. After the recent reform, ‘the way that retirement benefits are calculated’ is changed unfavorably for workers and the minimum age for retirement is increased. In particular, for an agent with 25 years of social security tax payments, the replacement rate is down from 65 percent to 50 percent. On the other hand, retirement age is up from 60 to 65. The aim of this paper is to investigate the macroeconomic effects of these changes using an OLG model. The author’s findings indicate that labor supply, output and capital stock increase when changes above are applied to the benchmark economy calibrated to the Turkish economy data in 2005. A critical change with the current reform is that the marginal benefit of working has become uniform over ages. In a simulation exercise, the marginal retirement benefit in the benchmark economy is changed to be uniform over ages while keeping the size of social security system unchanged. As a result, the benefit of retiring at a later period increases. However, uniform distribution of the marginal benefits itself decreases both the capital stock and output of the economy. Increasing the retirement age, on the other hand, has positive effects on the economy since agents obtain retirement benefits for fewer years and at an older age. Age increase has substantial positive effects on the labor supply, the capital stock, and the output.

  2. Biostable glucose permeable polymer

    DEFF Research Database (Denmark)

    2017-01-01

    A new biostable glucose permeable polymer has been developed which is useful, for example, in implantable glucose sensors. This biostable glucose permeable polymer has a number of advantageous characteristics and, for example, does not undergo hydrolytic cleavage and degradation, thereby providing...... a composition that facilitates long term sensor stability in vivo. The versatile characteristics of this polymer allow it to be used in a variety of contexts, for example to form the body of an implantable glucose sensor. The invention includes the polymer composition, sensor systems formed from this polymer...

  3. On the Baltic Sea Response to Climate Change: Model Implications

    International Nuclear Information System (INIS)

    Omstedt, Anders; Leppaeranta, Matti

    1999-01-01

    The sensitivity of the Baltic Sea to climate change is reviewed on the basis of recent model studies. In general, the presently available models indicate that the Baltic Sea is a most sensitive system to climate change, particularly in air temperature, wind, fresh water inflow and the barotropic forcing in the entrance area. Available scenarios for ice conditions and climate warming around year 2100 show 2-3 months' shortening of the ice season in the Bothnian Bay and about 0.4 m decrease in the maximum annual ice thickness. Corresponding scenarios for climate cooling show 1-2 months' longer ice season in the Bothnian Bay and 0.2 - 0.5 m increase in the maximum annual ice thickness

  4. Reading strategy instruction and teacher change: implications for teacher training

    Directory of Open Access Journals (Sweden)

    Nanda M Klapwijk

    2012-01-01

    Full Text Available I report on teacher change in the context of a reading strategy instruction intervention. Reading Strategy Instruction (RSI was implemented by three teachers, new to the concept, over a period of 15 weeks. Observations of these teachers showed that a multitude of factors affect the uptake of RSI as part of everyday teaching practice, and that teachers seem to move through distinct phases in their uptake of RSI. The article focuses on teachers' reaction to RSI and highlights a number of issues that are important to the implementation of RSI, not the least of which is that a clear need exists for changes to in-service teacher training and support and pre-service teacher training. In an effort to address these training issues the article contains specific recommendations for pre-service teacher training in particular.

  5. Implications of climate change in the ROPME region: an overview

    Energy Technology Data Exchange (ETDEWEB)

    Hassan, M.E.; Gerges, M.A.

    1994-12-31

    The Regional Organization for the Protection of the Marine Environment (ROPME) region is divided into three areas: SA-I, the northern part of the Arabian Sea bounded by the south coast of the Sultanate of Oman, the mouth of the Gulf of Oman and the southern coast of the Islamic Republic of Iran; SA-II, the Gulf of Oman; and SA-III named as the Persian or Arabian Gulf. SA-I is the prime representative of the monsoonal weather system, which produces strong summertime upwelling resulting in rich fisheries that disappear in the winter. SA-II shows transition between the monsoonal system and the desert belt climate of SA-III. Its shallowness mean that the annual range of water temperature is the greatest for any water body freely connected to the world ocean. This restricts the ecosystems that can survive. It also enhances the effect of sea level rise on the tidal pattern. Because the SA-III region is the world`s major oil and gas extraction area, resulting land subsidence can produce an apparent sea level rise of the same order of magnitude as that postulated from expected climate change. Observed sea level rise could be twice the global rate. The shallowness of the area means that the change of tidal pattern resulting from the change of depth will be very dramatic. To help combat climate change it is recommended that: a high quality dense tide recording network be set up and connected to a land subsidence recording network; a regional central data collecting and data processing centre be identified in the region; an active participation in international relevant programs such as TOGA and GOOS by ROPME Member States be maintained; and environmental non-Governmental Organizationsshould be encouraged to publicise these issues.

  6. Adapting to a changing world: Implications for water management.

    Science.gov (United States)

    Loucks, Daniel

    2010-05-01

    Everyone is aware that the world is changing, and that many of these changes will impact our water resource supplies and how they are used and managed. It's always a challenge to try to predict the future, especially the very uncertain distant future. But one thing is certain, the future environment our descendants will experience will differ from the economic, social, technological and natural conditions we experience today. Some aspects of the changes that are happening may not be under human control, but many are. And to the extent they are, we can influence that future. In this paper I attempt to speculate about a future some 40 to 50 years from now, and how water will need to be managed then. My goal is to motivate some thinking and discussion about how we as water managers can influence and prepare ourselves (or our successors) for that future. It will require collaboration among multiple disciplines to determine how best we as a profession can help society adapt to these changes, and this in turn will require all of us to learn how to work together more effectively than we do now. This theme fits in with the current interest in sustainability, for no matter how it is defined, sustainability makes us think about the long-term future. How do we develop and manage our natural and cultural resources in ways that benefit both us and future generations of people living on this earth? What will their needs and goals be? We don't know and that is the major challenge in deciding what decisions we might make today on their behalf. Here I attempt to identify the challenges and issues water managers could be addressing some 40 to 50 years from now, and what we in each of our disciplines, and together, can begin to do now to address them.

  7. The Water-Use Implications of a Changing Power Sector

    Science.gov (United States)

    Peer, R.; Sanders, K.

    2016-12-01

    Changing policies, declining natural gas prices due to shale production and, growing pressure for cleaner energy sources are causing significant shifts in the fuels and technologies utilized for US electricity generation. These shifts have already impacted the volumes of water required for cooling thermal power plants, imposing consequences for watersheds that have yet to be quantified. This research investigates how these regulatory, economic, and socially-driven changes in the power sector have impacted cooling water usage across the US, which currently represents nearly half of US water withdrawals. This study uses plant-specific fuel consumption, generation, and cooling water data to assess water usage trends in the power sector from 2008 to 2014 across HUC-8 hydrologic units. Over this period, transitions from steam-cycle coal and nuclear units towards combined-cycle natural gas units and renewables, as well as transitions from once-through cooling towards wet recirculating tower and dry cooling systems resulted in large shifts in water usage. Trends towards non-traditional cooling water sources such as recycled water reduced freshwater consumption in some watersheds. Although US cooling water withdrawals and consumption increased from 2008 to 2014 largely due to electricity demand growth, the average water withdrawn and consumed per unit of electricity generated decreased and remained similar in magnitude, respectively. Changes at the watershed scale were not uniform, with some experiencing significant water use reductions and environmental benefits, especially due to coal-fired power plant retirements. Results highlight the importance of evaluating both water withdrawals and consumption at local spatial scales, as these shifts have varying consequences on water availability and quality for downstream users and ecosystems. This analysis underscores the importance of prioritizing local water security in global climate change adaptation and mitigation efforts.

  8. Implications of climate change on landslide hazard in Central Italy.

    Science.gov (United States)

    Alvioli, Massimiliano; Melillo, Massimo; Guzzetti, Fausto; Rossi, Mauro; Palazzi, Elisa; von Hardenberg, Jost; Brunetti, Maria Teresa; Peruccacci, Silvia

    2018-07-15

    The relation between climate change and its potential effects on the stability of slopes remains an open issue. For rainfall induced landslides, the point consists in determining the effects of the projected changes in the duration and amounts of rainfall that can initiate slope failures. We investigated the relationship between fine-scale climate projections obtained by downscaling and the expected modifications in landslide occurrence in Central Italy. We used rainfall measurements taken by 56 rain gauges in the 9-year period 2003-2011, and the RainFARM technique to generate downscaled synthetic rainfall fields from regional climate model projections for the 14-year calibration period 2002-2015, and for the 40-year projection period 2010-2049. Using a specific algorithm, we extracted a number of rainfall events, i.e. rainfall periods separated by dry periods of no or negligible amount of rain, from the measured and the synthetic rainfall series. Then, we used the selected rainfall events to forcethe Transient Rainfall Infiltration and Grid-Based Regional Slope-Stability Model TRIGRS v. 2.1. We analyzed the results in terms of variations (or lack of variations) in the rainfall thresholds for the possible initiation of landslides, in the probability distribution of landslide size (area), and in landslide hazard. Results showed that the downscaled rainfall fields obtained by RainFARM can be used to single out rainfall events, and to force the slope stability model. Results further showed that while the rainfall thresholds for landslide occurrence are expected to change in future scenarios, the probability distribution of landslide areas are not. We infer that landslide hazard in the study area is expected to change in response to the projected variations in the rainfall conditions. We expect our results to contribute to regional investigations of the expected impact of projected climate variations on slope stability conditions and on landslide hazards. Copyright

  9. Reading strategy instruction and teacher change: implications for teacher training

    OpenAIRE

    Klapwijk, Nanda M

    2012-01-01

    I report on teacher change in the context of a reading strategy instruction intervention. Reading Strategy Instruction (RSI) was implemented by three teachers, new to the concept, over a period of 15 weeks. Observations of these teachers showed that a multitude of factors affect the uptake of RSI as part of everyday teaching practice, and that teachers seem to move through distinct phases in their uptake of RSI. The article focuses on teachers' reaction to RSI and highlights a number of issue...

  10. Geopolitical implications of climate change. Implicazioni geopolitiche dei mutamenti climatici

    Energy Technology Data Exchange (ETDEWEB)

    Mintzer, I [Center for Global Change, MA (USA)

    1991-01-01

    The geopolitical risks of rapid climate change have been divided into those that result from the direct effects of greenhouse warming and those that result from the indirect effects on patterns of precipitations. The most important direct stresses on international relations are the effects of sea level rise on coastal zones and those of warming water temperatures on coral reefs. The most important indirect stresses are related to the changes in precipitation patterns, in the frequency of weather related disasters and in crop production. The danger on low-lying areas is emphasized, with examples. In Egypt a one meter sea-level rise is estimated to flood an area containing about 15% of the population. A second set of potential risks is the possible destruction of coral reefs that protect many tropical islands, due to a combination of an increase of sea temperature and of marine pollution. Among the indirect effects of global warming, the changes in rainfall patterns could reduce water availability, thus increasing cross-border tensions in areas where river and lake resources are shared between different countries (as in the Middle East). Another important indirect effect is the decline in crop fertility that would dramaticllay increase demand for imported cereals. The opportunities to reduce the potential damages of global warming, from more resilient varieties of familiar cultivars to the introduction of communication facilities in rural areas and the development of decentralized network with food and medical supplies in the most vulnerable regions are presented. 1 ref., 2 figs., 1 tab.

  11. Ocean Biological Pump Sensitivities and Implications for Climate Change Impacts

    Science.gov (United States)

    Romanou, Anastasia

    2013-01-01

    The ocean is one of the principal reservoirs of CO2, a greenhouse gas, and therefore plays a crucial role in regulating Earth's climate. Currently, the ocean sequesters about a third of anthropogenic CO2 emissions, mitigating the human impact on climate. At the same time, the deeper ocean represents the largest carbon pool in the Earth System and processes that describe the transfer of carbon from the surface of the ocean to depth are intimately linked to the effectiveness of carbon sequestration.The ocean biological pump (OBP), which involves several biogeochemical processes, is a major pathway for transfer of carbon from the surface mixed layer into the ocean interior. About 75 of the carbon vertical gradient is due to the carbon pump with only 25 attributed to the solubility pump. However, the relative importance and role of the two pumps is poorly constrained. OBP is further divided to the organic carbon pump (soft tissue pump) and the carbonate pump, with the former exporting about 10 times more carbon than the latter through processes like remineralization.Major uncertainties about OBP, and hence in the carbon uptake and sequestration, stem from uncertainties in processes involved in OBP such as particulate organicinorganic carbon sinkingsettling, remineralization, microbial degradation of DOC and uptakegrowth rate changes of the ocean biology. The deep ocean is a major sink of atmospheric CO2 in scales of hundreds to thousands of years, but how the export efficiency (i.e. the fraction of total carbon fixation at the surface that is transported at depth) is affected by climate change remains largely undetermined. These processes affect the ocean chemistry (alkalinity, pH, DIC, particulate and dissolved organic carbon) as well as the ecology (biodiversity, functional groups and their interactions) in the ocean. It is important to have a rigorous, quantitative understanding of the uncertainties involved in the observational measurements, the models and the

  12. Defining clogging potential for permeable concrete.

    Science.gov (United States)

    Kia, Alalea; Wong, Hong S; Cheeseman, Christopher R

    2018-08-15

    Permeable concrete is used to reduce urban flooding as it allows water to flow through normally impermeable infrastructure. It is prone to clogging by particulate matter and predicting the long-term performance of permeable concrete is challenging as there is currently no reliable means of characterising clogging potential. This paper reports on the performance of a range of laboratory-prepared and commercial permeable concretes, close packed glass spheres and aggregate particles of varying size, exposed to different clogging methods to understand this phenomena. New methods were developed to study clogging and define clogging potential. The tests involved applying flowing water containing sand and/or clay in cycles, and measuring the change in permeability. Substantial permeability reductions were observed in all samples, particularly when exposed to sand and clay simultaneously. Three methods were used to define clogging potential based on measuring the initial permeability decay, half-life cycle and number of cycles to full clogging. We show for the first time strong linear correlations between these parameters for a wide range of samples, indicating their use for service-life prediction. Copyright © 2018 Elsevier Ltd. All rights reserved.

  13. Implications of shale gas development for climate change.

    Science.gov (United States)

    Newell, Richard G; Raimi, Daniel

    2014-01-01

    Advances in technologies for extracting oil and gas from shale formations have dramatically increased U.S. production of natural gas. As production expands domestically and abroad, natural gas prices will be lower than without shale gas. Lower prices have two main effects: increasing overall energy consumption, and encouraging substitution away from sources such as coal, nuclear, renewables, and electricity. We examine the evidence and analyze modeling projections to understand how these two dynamics affect greenhouse gas emissions. Most evidence indicates that natural gas as a substitute for coal in electricity production, gasoline in transport, and electricity in buildings decreases greenhouse gases, although as an electricity substitute this depends on the electricity mix displaced. Modeling suggests that absent substantial policy changes, increased natural gas production slightly increases overall energy use, more substantially encourages fuel-switching, and that the combined effect slightly alters economy wide GHG emissions; whether the net effect is a slight decrease or increase depends on modeling assumptions including upstream methane emissions. Our main conclusions are that natural gas can help reduce GHG emissions, but in the absence of targeted climate policy measures, it will not substantially change the course of global GHG concentrations. Abundant natural gas can, however, help reduce the costs of achieving GHG reduction goals.

  14. The family in Italy: cultural changes and implications for treatment.

    Science.gov (United States)

    Luciano, Mario; Sampogna, Gaia; del Vecchio, Valeria; Giacco, Domenico; Mulè, Alice; de Rosa, Corrado; Fiorillo, Andrea; Maj, Mario

    2012-04-01

    In Italy family is characterized by strong ties and is based on mutual aid of all its members. In the last 20 years, the structure of families has been significantly influenced by demographic, economic and professional changes, determining a transition from a patriarchal to a nuclear family model, with a higher number of single-parent families, single-person households, childless couples, same-sex couples. However, this transition has been slower than that occurring in other countries, probably as an ongoing impact of prevalent Catholic ideology. Major demographic changes in Italian families include, 1) a decrease in the number of marriages, delays in getting married and an high number of civil ceremonies, 2) a reduced birth rate; Italy is becoming one of the European countries with lowest growth rate, and with an increasing number of births out of wedlock, 3) an increased marital instability, with a constantly growing number of legal separations. Like many countries, relatives in Italy are highly involved in the care of patients with physical and mental disorders. There are a number of psychosocial interventions used in Italy including the 'Milan Systemic Approach' and family psycho-educational interventions. However, there are difficulties in implementing these interventions which are highlighted in this paper. We recommend research strategies to identify the best options to involve families in the care of mentally ill patients and to adequately support them.

  15. Earning and caring: demographic change and policy implications

    Directory of Open Access Journals (Sweden)

    Roderic Beaujot

    2002-12-01

    activities, we contrast theoretical orientations that see advantages to a division of labour or complementary roles, in comparison to orientations that see less risk and greater companionship in a collaborative model based on sharing paid and unpaid work, or co-providing and co-parenting. It is important to look both inside and outside of families, or at the changing gendered links between earning and caring, to understand change both in families and in the work world. It is proposed that equal opportunity by gender has advanced further in the public sphere associated with education and work, than in the private family sphere associated with everyday life. Time-use data indicate that, on average, men carry their weight in terms of total productive time (paid plus unpaid work, but that women make much more of the accommodations between family and work. Fertility is likely to be lowest in societies that offer women equal opportunity in the public sphere but where families remain traditional in terms of the division of work. Policies are discussed that would reduce the dependency between spouses, and encourage a greater common ground between men and women in earning and caring.

  16. Mergers and acquisitions: some implications of cultural change.

    Science.gov (United States)

    Cavanaugh, S J

    1996-01-01

    A result of recent National Health Service reforms is the need to investigate, and possibly change, the culture of the professional working relationship between members of staff and their employer. This is particularly the case in situations of mergers and acquisitions where staff working from different cultural environments must work together. Mergers are becoming a feature of health service provision, perhaps this becomes most obvious with the recent moves by colleges of nursing and midwifery into the higher education sector and amalgamations of some purchasing authorities. Mergers highlight the practical issues of bringing together different organizational and work cultures to deliver a high quality service. This article discusses some aspects of the nature of organizational culture, the human impact of mergers and acquisitions and offers strategies for managing these events.

  17. Implications of causality for quantum biology - I: topology change

    Science.gov (United States)

    Scofield, D. F.; Collins, T. C.

    2018-06-01

    A framework for describing the causal, topology changing, evolution of interacting biomolecules is developed. The quantum dynamical manifold equations (QDMEs) derived from this framework can be related to the causality restrictions implied by a finite speed of light and to Planck's constant to set a transition frequency scale. The QDMEs imply conserved stress-energy, angular-momentum and Noether currents. The functional whose extremisation leads to this result provides a causal, time-dependent, non-equilibrium generalisation of the Hohenberg-Kohn theorem. The system of dynamical equations derived from this functional and the currents J derived from the QDMEs are shown to be causal and consistent with the first and second laws of thermodynamics. This has the potential of allowing living systems to be quantum mechanically distinguished from non-living ones.

  18. UNEP-IOC-ASPEI global task team on the implications of climate change on coral reefs

    Energy Technology Data Exchange (ETDEWEB)

    1992-01-01

    The first meeting of the Global Task Team on the Implications of Climate Change on Coral Reefs was held to develop an authoritative scientific and technical review of the implications of climate change for coral reefs and their ecologically sustainable use. The Task Team is expected to provide expert advice and guidance in the implementation of the pilot activity on coral reef monitoring as part of the UNEP-IOC-WMO Long-Term Global Monitoring System of coastal and near-shore phenomena related to climate change. This would ensure coordination of various activities aimed at assessing the scale of impacts on natural environments and socio-economic systems particularly in the case of low-lying islands and other areas vulnerable to climate change and sea level rise. The work of the Task Team should ultimately assist the Governments concerned in mitigating the impacts of such changes.

  19. Earning and caring: demographic change and policy implications

    Directory of Open Access Journals (Sweden)

    Beaujot, Roderic

    2002-01-01

    Full Text Available EnglishSeeking to define families as groups of people who share earning and caringactivities, we contrast theoretical orientations that see advantages to a division of labour orcomplementary roles, in comparison to orientations that see less risk and greater companionship in acollaborative model based on sharing paid and unpaid work, or co-providing and co-parenting. It isimportant to look both inside and outside of families, or at the changing gendered links betweenearning and caring, to understand change both in families and in the work world. It is proposed thatequal opportunity by gender has advanced further in the public sphere associated with education andwork, than in the private family sphere associated with everyday life. Time-use data [from Canada]indicate that, on average, men carry their weight in terms of total productive time (paid plus unpaidwork, but that women make much more of the accommodations between family and work. Fertility islikely to be lowest in societies that offer women equal opportunity in the public sphere but wherefamilies remain traditional in terms of the division of work. Policies are discussed that would reducethe dependency between spouses, and encourage a greater common ground between men and women in earningand caring.FrenchEn cherchant à définir la famille comme étant un groupe de personnes partageant les activités relatives au fait de gagner de l'argent et de prendre soin des autres, nous nous distinguons des théories préconisant la division du travail ou les rôles complémentaires comparativement au modèle collaboratif qui a l'avantage de présenter moins de risque et plus de compagnonnage et qui est fondé sur le partage du travail rémunéré et non rémunéré, le travail à l'extérieur de la maison et le parentage. Il est important de voir ce qui se passe à l'intérieur et à l'extérieur de la famille ou de considérer les liens changeant d'après le sexe entre le rôle de pourvoyeur et

  20. Ultrastructural studies on the blood-brain barrier. Mainly as to changes in the permeability of cerebral capillary walls induced by experimental x-ray irradiation and the effect of glucocorticoid on such changes

    Energy Technology Data Exchange (ETDEWEB)

    Ichitsubo, H [Tokyo Medical Coll. (Japan)

    1977-03-01

    In the present study, an ultrastructural examination was made of the role of capillary endothelial cells of the brain which is one of the constituent factors of the blood-brain barrier. In normal cerebral capillaries, both endothelial cells and the basement membrane were demonstrated to be not crossed by a tracer (horseradish peroxidase) even in 60 minutes after its intravenous administration, thus suggesting the blood-brain barrier effect. Author investigated changes in the permeability of cerebral capillary walls induced by experimental brain irradiation and the effect of glucocorticoid on such changes. On forty-eight hours following an appropriate irradiation a marked brain edema was developed; under such circumstances when the tracer was injected intravenously, on 60 minutes thereafter the tracer was demonstrated to be transferred into the neutral tissue, and this was interpreted as indicating that capillary hyperpermeability was induced. These findings were suggested that the mechanism of capillary hyperpermeability might not be based on the passage of a tight junction of the cells of capillary wall but rather on account of activated active transport via an increased number of pinocytotic vesicles. The mechanism of increase of pinocytotic vesicle appeared to be resulting from a breakdown of the controlling system of pinocytotic vesicle production. However, the existence of this controlling system is still speculative. Pre-and post-irradiation administration of glucocorticoid proved to be effective in the prevention of irradiation-induced hyperpermeability of cerebral capillaries, and to be indicating the possible usefulness of the drug for the maintenance or repair of the aforementioned system.

  1. Implications of small modular reactors for climate change mitigation

    International Nuclear Information System (INIS)

    Iyer, Gokul; Hultman, Nathan; Fetter, Steve; Kim, Son H.

    2014-01-01

    Achieving climate policy targets will require large-scale deployment of low-carbon energy technologies, including nuclear power. The small modular reactor (SMR) is viewed as a possible solution to the problems of energy security as well as climate change. In this paper, we use an integrated assessment model (IAM) to investigate the evolution of a global energy portfolio with SMRs under a stringent climate policy. Technology selection in the model is based on costs; we use results from previous expert elicitation studies of SMR costs. We find that the costs of achieving a 2 °C target are lower with SMRs than without. The costs are higher when large reactors do not compete for market share compared to a world in which they can compete freely. When both SMRs and large reactors compete for market share, reduction in mitigation cost is achieved only under advanced assumptions about SMR technology costs and future cost improvements. While the availability of SMRs could lower mitigation costs by a moderate amount, actual realization of these benefits would depend on the rapid up-scaling of SMRs in the near term. Such rapid deployment could be limited by several social, institutional and behavioral obstacles. - Highlights: • Costs of achieving a 2 °C target are lower with SMRs than without. • Costs are higher when large reactors do not compete for market share. • Under competition, cost is reduced only with advanced SMR technology. • Realization of benefits will depend on rapid near term up-scaling of SMRs

  2. Implications for Academic Workload of the Changing Role of Distance Educators

    Science.gov (United States)

    Bezuidenhout, Adéle

    2015-01-01

    The changing work roles and resulting workloads of distance educators hold significant implications for the wellbeing and mental health of academics. New work roles include redesigning curricula for online delivery, increasing staff-student ratios and demands for student-support, management of part-time staff, and 24-h availability. This research…

  3. Implications of land-use change on forest carbon stocks in the eastern United States

    Science.gov (United States)

    Joshua Puhlick; Christopher Woodall; Aaron Weiskittel

    2017-01-01

    Given the substantial role that forests play in removing CO2 from the atmosphere, there has been a growing need to evaluate the carbon (C) implications of various forest management and land-use decisions. Although assessment of land-use change is central to national-level greenhouse gas monitoring guidelines, it is rarely incorporated into forest...

  4. A Review of Physiological and Psychological Changes in Aging and Their Implications for Teachers of Adults.

    Science.gov (United States)

    Hand, Samuel E.

    This review of literature on the aging process points out primary physiological and psychological changes in maturing adults which have implications for teachers of adults. Visual acuity and hearing decline during adult years and there is a general slowing down process of most bodily activities. Teachers should be aware of the need for good…

  5. Economy-wide Estimates of the Implications of Climate Change - A Rejoinder

    NARCIS (Netherlands)

    Bosello, F.; Roson, R.; Tol, R.S.J.

    2008-01-01

    [Ackermann, F., Stanton, E., 2008-this issue. A comment on economy-wide estimates of the implications of climate change: human health. Ecological Economics. doi:10.1016/j.ecolecon.2007.10.006] criticise our recent paper [Bosello, F., Roson, R., Tol, R.S.J., 2006. Economy-wide estimates of the

  6. Functional implications of changes in seagrass species composition in two shallow coastal lagoons

    Science.gov (United States)

    While the consequences of losing seagrass meadows are well known, there is less information on the functional implications of changes in seagrass species composition. In this study, we use data from a long-term monitoring project in shallow lagoons on the Florida Gulf Coast to as...

  7. Psychology of change: Models and implications for nuclear plants in an era of deregulation

    International Nuclear Information System (INIS)

    Gates, W.G.; Stark, J.A.

    1999-01-01

    This presentation explores the psychology of change in the implications that it has for nuclear plants during this era of deregulation. The authors analyze models that work, models that have failed in the past, and specific findings and applications based on 2 yr of research, as well as the results regarding the impact of the psychology of change on the Fort Calhoun nuclear station in Nebraska

  8. 高压水力压裂和二氧化碳相变致裂联合增透技术%Combined permeability improved technology with high pressure hydraulic fracturing and carbon dioxide phase change cracking

    Institute of Scientific and Technical Information of China (English)

    秦江涛; 陈玉涛; 黄文祥

    2017-01-01

    针对白皎煤矿地质构造复杂、构造应力大、煤层透气性差、抽采瓦斯效果差的问题,提出了高压水力压裂和二氧化碳相变致裂联合增透技术,分析了水力压裂和二氧化碳相变致裂联合增透技术的原理;并在238底板巷对B4煤层进行了联合增透对比试验研究.试验结果表明:试验区域煤层透气性显著提高,单孔初抽瓦斯体积分数分别是高压水力压裂试验区域和普通抽采试验区域平均瓦斯体积分数的1.70、3.48倍;瓦斯抽采纯量较水力压裂区域和普通抽采区域分别提高了1.49、3.04倍;抽采65 d以后,高压水力压裂和二氧化碳相变致裂联合增透区域汇总瓦斯体积分数仍保持在40%以上,抽采效果良好,该技术可供类似矿井借鉴.%According to the problems of complicated geological tectonics,high tectonic stress,poor seam permeability and poor gas drainage effect in Baijiao Mine,a permeability improved technology combined with a high pressure hydraulic fracturing and carbon dioxide phase change cracking was provided and the principle of the hydraulic fracturing and carbon dioxide combined permeability improved technology was analyzed.A comparison experiment study was conducted on the combined permeability improvement of No.B4 Seam in No.238 floor gateway.The experiment results showed that the permeability of the seam in the technical experiment area was remarkably improved and the initial drained gas volume fraction of a single borehole was 1.70 times and 3.48 times higher than the average volume fractions of the high pressure hydraulic fracturing area and the conventional gas drainage trial area individually.The gas drainage pure volume was improved by 1.49 and 3.04 times higher than the hydraulic fracturing area and the conventional gas drainage area individually.After 65 days of the gas drainage operation,the total gas volume fraction of the high pressure hydraulic fracturing and carbon dioxide phase change

  9. The economics of energy policy in China. Implications for global climate change

    International Nuclear Information System (INIS)

    Zhongxiang Zhang

    1998-01-01

    This book is the first systematic and comprehensive attempt to deal with the economic implications of carbon abatement for the Chinese economy in the light of the economics of climate change. The book provides 1) an analysis of the Chinese energy system in order to shed light on its implications for China's future CO 2 emissions; 2) a macroeconomic analysis of CO 2 emission limits for China, using a newly-developed computable general equilibrium model of the Chinese economy; and 3) a cost-effective analysis of carbon abatement options in China's electricity sector by means of a technology-oriented dynamic optimization model. (UK)

  10. Small-bowel permeability in collagenous colitis

    DEFF Research Database (Denmark)

    Wildt, Signe; Madsen, Jan L; Rumessen, Jüri J

    2006-01-01

    Collagenous colitis (CC) is a chronic inflammatory bowel disease that affects the colon. However, some patients with CC present with accompanying pathologic small-bowel manifestations such as coeliac disease, defects in bile acid absorption and histopathologic changes in small-intestinal biopsies......, indicating that CC is a pan-intestinal disease. In small-intestinal disease, the intestinal barrier function may be impaired, and the permeability of the small intestine altered. The purpose of this research was to study small-bowel function in patients with CC as expressed by intestinal permeability....

  11. Vascular permeability and iron deposition biomarkers in longitudinal follow-up of cerebral cavernous malformations

    DEFF Research Database (Denmark)

    Girard, Romuald; Fam, Maged D; Zeineddine, Hussein A

    2017-01-01

    OBJECTIVE Vascular permeability and iron leakage are central features of cerebral cavernous malformation (CCM) pathogenesis. The authors aimed to correlate prospective clinical behavior of CCM lesions with longitudinal changes in biomarkers of dynamic contrast-enhanced quantitative permeability (...

  12. 75 FR 43944 - Defense Science Board; Task Force on Trends and Implications of Climate Change for National and...

    Science.gov (United States)

    2010-07-27

    ... DEPARTMENT OF DEFENSE Office of the Secretary Defense Science Board; Task Force on Trends and Implications of Climate Change for National and International Security AGENCY: Department of Defense (DoD... and Implications of Climate Change for National and International Security will meet in closed session...

  13. 75 FR 34438 - Defense Science Board Task Force on Trends and Implications of Climate Change for National and...

    Science.gov (United States)

    2010-06-17

    ... DEPARTMENT OF DEFENSE Office of the Secretary Defense Science Board Task Force on Trends and Implications of Climate Change for National and International Security AGENCY: Department of Defense (DoD... and Implications of Climate Change for National and International Security will meet in closed session...

  14. Climate change due to the greenhouse effect and its implications for China

    Energy Technology Data Exchange (ETDEWEB)

    Hulme, M.; Wigley, T.; Jiang, T.; Zhao, Z.; Wang, F.; Ding, Y.; Leemans, R.; Markham, A.

    1992-01-01

    The report describes the greenhouse effect, past climate changes, and forecasts. The implications for China, and for policies are discussed. Over China, warming has been greater (nearly 1.0[degree]C since the last century) than over the rest of the planet. It is also more pronounced in winter. Climatic change would have a substantial impact on natural vegetation in China. By 2050, large changes in cropping systems would occur. Sea level rise is likely to affect some densely populated areas. 14 refs., 24 figs., 8 tabs.

  15. Bovine colostrum increases pore-forming claudin-2 protein expression but paradoxically not ion permeability possibly by a change of the intestinal cytokine milieu.

    Directory of Open Access Journals (Sweden)

    Peggy Bodammer

    Full Text Available An impaired intestinal barrier function is involved in the pathogenesis of inflammatory bowel disease (IBD. Several nutritional factors are supposed to be effective in IBD treatment but scientific data about the effects on the intestinal integrity remain scarce. Bovine colostrum was shown to exert beneficial effects in DSS-induced murine colitis, and the present study was undertaken to explore the underlying molecular mechanisms. Western blot revealed increased claudin-2 expression in the distal ileum of healthy mice after feeding with colostrum for 14 days, whereas other tight junction proteins (claudin-3, 4, 10, 15 remained unchanged. The colostrum-induced claudin-2 induction was confirmed in differentiated Caco-2 cells after culture with colostrum for 48 h. Paradoxically, the elevation of claudin-2, which forms a cation-selective pore, was neither accompanied by increased ion permeability nor impaired barrier function. In an in situ perfusion model, 1 h exposure of the colonic mucosa to colostrum induced significantly increased mRNA levels of barrier-strengthening cytokine transforming growth factor-β, while interleukine-2, interleukine-6, interleukine-10, interleukine-13, and tumor-necrosis factor-α remained unchanged. Thus, modulation of the intestinal transforming growth factor-β expression might have compensated the claudin-2 increase and contributed to the observed barrier strengthening effects of colostrum in vivo and in vitro.

  16. Permeability measuremens of brazilian Eucalyptus

    Directory of Open Access Journals (Sweden)

    Marcio Rogério da Silva

    2010-09-01

    Full Text Available The permeability of Brazilian Eucalyptus grandis and Eucalyptus citriodora wood was measured in a custom build gas analysis chamber in order to determine which species could be successfully treated with preservatives. Liquid permeability was tested using an emulsion of Neen oil and a control of distillated water. Air was used to test the gas phase permeability. For both Eucalyptus grandis and Eucalyptus citriodora, the longitudinal permeability of gas was shown to be about twice as great as the liquid phase permeability. No radial permeability was observed for either wood. The permeability of air and water through the sapwood of Eucalyptus grandis was greater than that through the sapwood of Eucalyptus citriodora. The permeability of neen oil preservative through the sapwood of Eucalyptus grandis was also greater than through the sapwood of E. Citradora, but the difference was not statistically significant. Scanning Electron Microscopy images showed that the distribution and obstruction in the vessels could be correlated with observed permeability properties. Irrespective of the causes of differences in permeability between the species, the fluid phase flux through the sapwood of both species was significant, indicating that both Eucalyptus grandis and Eucalyptus citriodora could be successfully treated with wood preservative.

  17. Changing and Changed Stance toward Norm Selection in Philippine Universities: Its Pedagogical Implications

    Science.gov (United States)

    Bernardo, Alejandro S.

    2014-01-01

    This paper reports the results of a survey which involved College English teachers from three leading universities in the Philippines. The results point to one conclusion--College English teachers now have a changing and changed stance toward norm selection in Philippine Universities. The results give the impression that a good number of College…

  18. Implications of changing scattering properties on Greenland ice sheet volume change from Cryosat-2 altimetry

    DEFF Research Database (Denmark)

    Simonsen, Sebastian Bjerregaard; Sørensen, Louise Sandberg

    2017-01-01

    ) in the elevation change algorithm, to correct for temporal changes in the ratio between surface- and volume-scatter in Cryosat-2 observations. We present elevation and volume changes for the Greenland ice sheet in the period from 2010 until 2014. The waveform parameters considered here are the backscatter...... waveform parameters to be applicable for correcting for changes in volume scattering. The best results in the Synthetic Aperture Radar Interferometric mode area of the GrIS are found when applying only the backscatter correction, whereas the best result in the Low Resolution Mode area is obtained by only......Long-term observations of surface elevation change of the Greenland ice sheet (GrIS) is of utmost importance when assessing the state of the ice sheet. Satellite radar altimetry offers a long time series of data over the GrIS, starting with ERS-1 in 1991. ESA's Cryosat-2 mission, launched in 2010...

  19. Climate Change, Climate Justice, and Environmental Health: Implications for the Nursing Profession.

    Science.gov (United States)

    Nicholas, Patrice K; Breakey, Suellen

    2017-11-01

    Climate change is an emerging challenge linked to negative outcomes for the environment and human health. Since the 1960s, there has been a growing recognition of the need to address climate change and the impact of greenhouse gas emissions implicated in the warming of our planet. There are also deleterious health outcomes linked to complex climate changes that are emerging in the 21st century. This article addresses the social justice issues associated with climate change and human health and discussion of climate justice. Discussion paper. A literature search of electronic databases was conducted for articles, texts, and documents related to climate change, climate justice, and human health. The literature suggests that those who contribute least to global warming are those who will disproportionately be affected by the negative health outcomes of climate change. The concept of climate justice and the role of the Mary Robinson Foundation-Climate Justice are discussed within a framework of nursing's professional responsibility and the importance of social justice for the world's people. The nursing profession must take a leadership role in engaging in policy and advocacy discussions in addressing the looming problems associated with climate change. Nursing organizations have adopted resolutions and engaged in leadership roles to address climate change at the local, regional, national, and global level. It is essential that nurses embrace concepts related to social justice and engage in the policy debate regarding the deleterious effects on human health related to global warming and climate change. Nursing's commitment to social justice offers an opportunity to offer significant global leadership in addressing the health implications related to climate change. Recognizing the negative impacts of climate change on well-being and the underlying socioeconomic reasons for their disproportionate and inequitable distribution can expand and optimize the profession's role

  20. Frictional stability-permeability relationships for fractures in shales

    Science.gov (United States)

    Fang, Yi; Elsworth, Derek; Wang, Chaoyi; Ishibashi, Takuya; Fitts, Jeffrey P.

    2017-03-01

    There is wide concern that fluid injection in the subsurface, such as for the stimulation of shale reservoirs or for geological CO2 sequestration (GCS), has the potential to induce seismicity that may change reservoir permeability due to fault slip. However, the impact of induced seismicity on fracture permeability evolution remains unclear due to the spectrum of modes of fault reactivation (e.g., stable versus unstable). As seismicity is controlled by the frictional response of fractures, we explore friction-stability-permeability relationships through the concurrent measurement of frictional and hydraulic properties of artificial fractures in Green River shale (GRS) and Opalinus shale (OPS). We observe that carbonate-rich GRS shows higher frictional strength but weak neutral frictional stability. The GRS fracture permeability declines during shearing while an increased sliding velocity reduces the rate of permeability decline. By comparison, the phyllosilicate-rich OPS has lower friction and strong stability while the fracture permeability is reduced due to the swelling behavior that dominates over the shearing induced permeability reduction. Hence, we conclude that the friction-stability-permeability relationship of a fracture is largely controlled by mineral composition and that shale mineral compositions with strong frictional stability may be particularly subject to permanent permeability reduction during fluid infiltration.

  1. The Implications of Changing Power Generation Mix on Energy Pricing and Security in Ghana

    OpenAIRE

    Acheampong, Theophilus

    2016-01-01

    Despite almost a decade of strong economic growth, Ghana still lags behind in its ability to generate enough power to catalyse this growth. The rapid deceleration in economic activity over the past three years has been primarily due to persistent energy supply constraints and rising energy-related input costs to production. This article analyses the implications of the changing power generation mix for electricity pricing in Ghana taking into account new capacity additions to the generation m...

  2. The implications of psychological limitations for the ethics of climate change

    DEFF Research Database (Denmark)

    Kasperbauer, Tyler Joshua

    2016-01-01

    Most philosophers and psychologists who have explored the psychology of climate change have focused only on motivational issues - getting people to act on what morality requires of them. This is misleading, however, because there are other psychological processes directed not at motivation...... but rather our ability to grasp the implications of climate change in a general way - what Stephen Gardiner has called the 'grasping problem'. Taking the grasping problem as my departure point, I draw two conclusions from the relevant psychological literature: 1) ethicists and policy makers should focus less...... on changing individuals' behaviours and more on changing policy; and 2) although solutions to climate change must come at the level of policy, progress on this front will be limited by incompatible moral norms....

  3. Stress dependence of permeability of intact and fractured shale cores.

    Science.gov (United States)

    van Noort, Reinier; Yarushina, Viktoriya

    2016-04-01

    Whether a shale acts as a caprock, source rock, or reservoir, understanding fluid flow through shale is of major importance for understanding fluid flow in geological systems. Because of the low permeability of shale, flow is thought to be largely confined to fractures and similar features. In fracking operations, fractures are induced specifically to allow for hydrocarbon exploration. We have constructed an experimental setup to measure core permeabilities, using constant flow or a transient pulse. In this setup, we have measured the permeability of intact and fractured shale core samples, using either water or supercritical CO2 as the transporting fluid. Our measurements show decreasing permeability with increasing confining pressure, mainly due to time-dependent creep. Furthermore, our measurements show that for a simple splitting fracture, time-dependent creep will also eliminate any significant effect of this fracture on permeability. This effect of confinement on fracture permeability can have important implications regarding the effects of fracturing on shale permeability, and hence for operations depending on that.

  4. Downscaled Climate Change Projections for the Southern Colorado Plateau: Variability and Implications for Vegetation Changes

    Science.gov (United States)

    Garfin, G. M.; Eischeid, J. K.; Cole, K. L.; Ironside, K.; Cobb, N. S.

    2008-12-01

    Recent and rapid forest mortality in western North America and associated changes in fire frequency and area burned are among the chief concerns of ecosystem managers. These examples of climate change surprises demonstrate nonlinear and threshold ecosystem responses to increased temperatures and severe drought. A consistent management request from climate change adaptation workshops held during the last four years in the southwest U.S. is for region-specific estimates of climate and vegetation change, in order to provide guidance for management of federal and state forest, range, and riparian preserves and land holdings. Partly in response to these concerns, and partly in the interest of improving knowledge of potential ecosystem changes and their relationships with observed changes and changes demonstrated in the paleoecological record, we developed a set of integrated climate and ecosystem analyses. We selected five of twenty-two GCMs from the PCMDI archive of IPCC AR4 model runs, based on their approximations of observed critical seasonality for vegetation in the Southern Colorado Plateau (domain: 35°- 38°N, 114°-107°W), centered on the Four Corners states. We used three key seasons in our analysis, winter (November-March), pre-monsoon (May-June), and monsoon (July- September). Projections of monthly and seasonal temperature and precipitation from our five-model ensemble indicate steadily increasing temperatures in our region of interest during the twenty-first century. By 2050, the ensemble projects increases of 3.0°C during May and June, months critical for drought stress and tree mortality, and 4.5-5.0°C by 2090. Projected temperature changes for months during the heart of winter (December and January) are on the order of 2.5°C by 2050 and 3.0°C by 2090; such changes are likely to affect snow hydrology in middle to low elevations in the Southern Colorado Plateau. Summer temperature increases are on the order of 2.5°C (2050) and 4.0°C (2090). The

  5. Land use change in China: implication for human-environmental interactions

    Science.gov (United States)

    cui, Xuefeng

    2013-04-01

    China's land use has undergone significant changes in history due to the continuous transformations caused by natural and human factors. This paper will review the history of land use changes in China during the past 300 years to identify the major transition periods and discuss the implications for environmental management. Population changes are found to be the primary driving factor in cropland expansion and deforestation in history for a long period. In 1950s, after the foundation of the Republic of China, all land use types experience a huge transition showing the determination of socio-economic policies in modern time after agricultural intensifications. Several current environmental policy in China will also be discussed to explore the effect of policy on land use changes.

  6. Ozone changes under solar geoengineering: implications for UV exposure and air quality

    Science.gov (United States)

    Nowack, P. J.; Abraham, N. L.; Braesicke, P.; Pyle, J. A.

    2015-11-01

    Various forms of geoengineering have been proposed to counter anthropogenic climate change. Methods which aim to modify the Earth's energy balance by reducing insolation are often subsumed under the term Solar Radiation Management (SRM). Here, we present results of a standard SRM modelling experiment in which the incoming solar irradiance is reduced to offset the global mean warming induced by a quadrupling of atmospheric carbon dioxide. For the first time in an atmosphere-ocean coupled climate model, we include atmospheric composition feedbacks such as ozone changes under this scenario. Including the composition changes, we find large reductions in surface UV-B irradiance, with implications for vitamin D production, and increases in surface ozone concentrations, both of which could be important for human health. We highlight that both tropospheric and stratospheric ozone changes should be considered in the assessment of any SRM scheme, due to their important roles in regulating UV exposure and air quality.

  7. Executive summary: Climate change in the northwest: Implications for our landscapes, waters, and communities

    Science.gov (United States)

    Dalton, Meghan M.; Bethel, Jeffrey; Capalbo, Susan M.; Cuhaciyan, J.E.; Eigenbrode, Sanford D.; Glick, Patty; Houston, Laurie L.; Littell, Jeremy S.; Lynn, Kathy; Mote, Philip W.; Raymondi, Rick R.; Reeder, W. Spencer; Shafer, Sarah L.; Snover, Amy K.

    2013-01-01

    Climate Change in the Northwest: Implications for Our Landscapes, Waters, and Communities is aimed at assessing the state of knowledge about key climate impacts and consequences to various sectors and communities in the northwest United States. It draws on a wealth of peer-reviewed literature, earlier state-level assessment reports conducted for Washington (2009) and Oregon (2010), as well as a risk-framing workshop. As an assessment, it aims to be representative (though not exhaustive) of the key climate change issues as reflected in the growing body of Northwest climate change science, impacts, and adaptation literature now available. This report will serve as an updated resource for scientists, stakeholders, decision makers, students, and community members interested in understanding and preparing for climate change impacts on Oregon, Washington, and Idaho. This more detailed, foundational report is intended to support the key findings presented in the Northwest chapter of the Third National Climate Assessment.

  8. Water Discharge and Sediment Load Changes in China: Change Patterns, Causes, and Implications

    Directory of Open Access Journals (Sweden)

    Chong Jiang

    2015-10-01

    Full Text Available In this research, monthly hydrological and daily meteorological data were collected across China for the period 1956–2012. Modified Mann–Kendall tests, double mass curve analysis, and correlation statistics were performed to identify the long-term trends and interrelation of the hydrometeorological variables and to examine the influencing factors of streamflow and sediment. The results are as follows: (1 In the last 60 years, the streamflow in northern China has shown different decreasing trends. For the southern rivers, the streamflow presented severe fluctuations, but the declining trend was insignificant. For the streamflow in western China, an increasing trend was shown. (2 In the northern rivers, the streamflow was jointly controlled by the East Asian monsoon and westerlies. In the southern rivers, the runoff was mainly influenced by the Tibet–Qinghai monsoon, the South Asian monsoon, and westerlies. (3 Sediment loads in the LCRB (Lancang River Basin and YZRB (Yarlung Zangbo River Basin did not present significant change trends, although other rivers showed different degrees of gradual reduction, particularly in the 2000s. (4 Underlying surface and precipitation changes jointly influenced the streamflow in eastern rivers. The water consumption for industrial and residential purposes, soil and water conservation engineering, hydraulic engineering, and underlying surface changes induced by other factors were the main causes of streamflow and sediment reduction.

  9. Coupling Flow & Transport Modeling with Electromagnetic Geophysics to Better Understand Crustal Permeability

    Science.gov (United States)

    Pepin, J.; Folsom, M.; Person, M. A.; Kelley, S.; Gomez-Velez, J. D.; Peacock, J.

    2016-12-01

    Over the last 30 years, considerable effort has focused on understanding the distribution of permeability within the earth's crust and its implications for flow and transport. The scarcity of direct observations makes the description of permeabilities beyond depths of about 3 km particularly challenging. Numerous studies have defined depth-decay relationships for basement permeability, while others note that it is too complex to be characterized by a general relationship. Hydrothermal modeling studies focusing on two geothermal systems within the tectonically active Rio Grande rift of New Mexico suggest that there may be laterally extensive regions of highly permeable (10-14 to 10-12 m2) basement rocks at depths ranging between 4 and 8 km. The NaCl groundwater signature, elevated fracture density, and secondary mineralization of fractured basement outcrops associated with these geothermal systems indicate that there may indeed be significant groundwater flow within the basement rocks of the rift. We hypothesize that there are extensive regions of highly permeable crystalline basement rocks at depths greater than 3 km within the Rio Grande rift. These fractured zones serve as large conduits for geothermal fluids before they ascend to shallow depths through gaps in overlying confining sediments or along faults. To test these hypotheses, we use a combination of geophysical observations and flow and transport modeling. We used electromagnetic geophysics (TEM & MT) to image resistivity in one of the hypothesized deep circulation geothermal systems near Truth or Consequences, NM. The resistivity dataset, in tandem with geochemical and thermal observations, is then used to calibrate a hydrothermal model of the system. This new calibration methodology has the potential to change the way researchers study crustal fluid flow and geothermal systems; thereby providing a tool to explore depths greater than 3 km where minimal data is available. In addition, it has the advantage

  10. Predicting chemically-induced skin reactions. Part II: QSAR models of skin permeability and the relationships between skin permeability and skin sensitization

    International Nuclear Information System (INIS)

    Alves, Vinicius M.; Muratov, Eugene; Fourches, Denis; Strickland, Judy; Kleinstreuer, Nicole; Andrade, Carolina H.; Tropsha, Alexander

    2015-01-01

    Skin permeability is widely considered to be mechanistically implicated in chemically-induced skin sensitization. Although many chemicals have been identified as skin sensitizers, there have been very few reports analyzing the relationships between molecular structure and skin permeability of sensitizers and non-sensitizers. The goals of this study were to: (i) compile, curate, and integrate the largest publicly available dataset of chemicals studied for their skin permeability; (ii) develop and rigorously validate QSAR models to predict skin permeability; and (iii) explore the complex relationships between skin sensitization and skin permeability. Based on the largest publicly available dataset compiled in this study, we found no overall correlation between skin permeability and skin sensitization. In addition, cross-species correlation coefficient between human and rodent permeability data was found to be as low as R 2 = 0.44. Human skin permeability models based on the random forest method have been developed and validated using OECD-compliant QSAR modeling workflow. Their external accuracy was high (Q 2 ext = 0.73 for 63% of external compounds inside the applicability domain). The extended analysis using both experimentally-measured and QSAR-imputed data still confirmed the absence of any overall concordance between skin permeability and skin sensitization. This observation suggests that chemical modifications that affect skin permeability should not be presumed a priori to modulate the sensitization potential of chemicals. The models reported herein as well as those developed in the companion paper on skin sensitization suggest that it may be possible to rationally design compounds with the desired high skin permeability but low sensitization potential. - Highlights: • It was compiled the largest publicly-available skin permeability dataset. • Predictive QSAR models were developed for skin permeability. • No concordance between skin sensitization and

  11. Predicting chemically-induced skin reactions. Part II: QSAR models of skin permeability and the relationships between skin permeability and skin sensitization

    Energy Technology Data Exchange (ETDEWEB)

    Alves, Vinicius M. [Laboratory of Molecular Modeling and Design, Faculty of Pharmacy, Federal University of Goiás, Goiânia, GO 74605-220 (Brazil); Laboratory for Molecular Modeling, Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC 27599 (United States); Muratov, Eugene [Laboratory for Molecular Modeling, Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC 27599 (United States); Laboratory of Theoretical Chemistry, A.V. Bogatsky Physical–Chemical Institute NAS of Ukraine, Odessa 65080 (Ukraine); Fourches, Denis [Laboratory for Molecular Modeling, Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC 27599 (United States); Strickland, Judy; Kleinstreuer, Nicole [ILS/Contractor supporting the NTP Interagency Center for the Evaluation of Alternative Toxicological Methods (NICEATM), P.O. Box 13501, Research Triangle Park, NC 27709 (United States); Andrade, Carolina H. [Laboratory of Molecular Modeling and Design, Faculty of Pharmacy, Federal University of Goiás, Goiânia, GO 74605-220 (Brazil); Tropsha, Alexander, E-mail: alex_tropsha@unc.edu [Laboratory for Molecular Modeling, Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC 27599 (United States)

    2015-04-15

    Skin permeability is widely considered to be mechanistically implicated in chemically-induced skin sensitization. Although many chemicals have been identified as skin sensitizers, there have been very few reports analyzing the relationships between molecular structure and skin permeability of sensitizers and non-sensitizers. The goals of this study were to: (i) compile, curate, and integrate the largest publicly available dataset of chemicals studied for their skin permeability; (ii) develop and rigorously validate QSAR models to predict skin permeability; and (iii) explore the complex relationships between skin sensitization and skin permeability. Based on the largest publicly available dataset compiled in this study, we found no overall correlation between skin permeability and skin sensitization. In addition, cross-species correlation coefficient between human and rodent permeability data was found to be as low as R{sup 2} = 0.44. Human skin permeability models based on the random forest method have been developed and validated using OECD-compliant QSAR modeling workflow. Their external accuracy was high (Q{sup 2}{sub ext} = 0.73 for 63% of external compounds inside the applicability domain). The extended analysis using both experimentally-measured and QSAR-imputed data still confirmed the absence of any overall concordance between skin permeability and skin sensitization. This observation suggests that chemical modifications that affect skin permeability should not be presumed a priori to modulate the sensitization potential of chemicals. The models reported herein as well as those developed in the companion paper on skin sensitization suggest that it may be possible to rationally design compounds with the desired high skin permeability but low sensitization potential. - Highlights: • It was compiled the largest publicly-available skin permeability dataset. • Predictive QSAR models were developed for skin permeability. • No concordance between skin

  12. The economics of energy policy in China. Implications for global climate change

    Energy Technology Data Exchange (ETDEWEB)

    Zhongxiang Zhang [Groningen Univ., Dept. of Economics and Public Finance, Groningen (Netherlands)]|[Chinese Academy of Social Sciences, Centre for Environment and Development, Beijing (China)

    1998-08-01

    This book is the first systematic and comprehensive attempt to deal with the economic implications of carbon abatement for the Chinese economy in the light of the economics of climate change. The book provides 1) an analysis of the Chinese energy system in order to shed light on its implications for China`s future CO{sub 2} emissions; 2) a macroeconomic analysis of CO{sub 2} emission limits for China, using a newly-developed computable general equilibrium model of the Chinese economy; and 3) a cost-effective analysis of carbon abatement options in China`s electricity sector by means of a technology-oriented dynamic optimization model. (UK)

  13. Recent changes in carbon dioxide, carbon monoxide and methane and the implications for global climate change

    Energy Technology Data Exchange (ETDEWEB)

    Novelli, P.C.; Conway, T.J.; Dlugokencky, E.J.; Tans, P.P. [National Oceanic and Atmospheric Administration, Boulder, CO (United States). Climate Monitoring and Diagnostics Lab.

    1995-01-01

    The article reviews figures for published data on recent changes of atmospheric levels of carbon dioxide, carbon monoxide and methane in terms of their sources and sinks. The largest source of CO{sub 2} is the combustion of fossil fuels, followed by emissions from deforestation and the oxidation of CO to CO{sub 2}. Carbon monoxide has an indirect influence on the earth`s radiative balance, as if levels of CO increase, levels of OH radicals decline which affects removal of other gases oxidised by this radical, notably CH{sub 4}. Major sources of CO are fossil fuel combustion, emissions from biomass, and oxidation of atmospheric CH{sub 4} and other non-methane hydrocarbons. The latest measurements suggest the depressed growth rates of CO{sub 2}, CO and CH{sub 4} have began to recover. Reasons for this are suggested. Future monitoring of atmospheric species in laboratories around the world, coupled with information on the isotopic signature of the trace gases, will improve our understanding of possible causes for trends in these gases. This will be invaluable in making policy decisions regarding future climate change. 34 refs., 4 figs.

  14. Electrokinetic effects and fluid permeability

    International Nuclear Information System (INIS)

    Berryman, J.G.

    2003-01-01

    Fluid permeability of porous media depends mainly on connectivity of the pore space and two physical parameters: porosity and a pertinent length-scale parameter. Electrical imaging methods typically establish connectivity and directly measure electrical conductivity, which can then often be related to porosity by Archie's law. When electrical phase measurements are made in addition to the amplitude measurements, information about the pertinent length scale can then be obtained. Since fluid permeability controls the ability to flush unwanted fluid contaminants from the subsurface, inexpensive maps of permeability could improve planning strategies for remediation efforts. Detailed knowledge of fluid permeability is also important for oil field exploitation, where knowledge of permeability distribution in three dimensions is a common requirement for petroleum reservoir simulation and analysis, as well as for estimates on the economics of recovery

  15. Health Systems Research in a Complex and Rapidly Changing Context: Ethical Implications of Major Health Systems Change at Scale.

    Science.gov (United States)

    MacGregor, Hayley; Bloom, Gerald

    2016-12-01

    This paper discusses health policy and systems research in complex and rapidly changing contexts. It focuses on ethical issues at stake for researchers working with government policy makers to provide evidence to inform major health systems change at scale, particularly when the dynamic nature of the context and ongoing challenges to the health system can result in unpredictable outcomes. We focus on situations where 'country ownership' of HSR is relatively well established and where there is significant involvement of local researchers and close ties and relationships with policy makers are often present. We frame our discussion around two country case studies with which we are familiar, namely China and South Africa and discuss the implications for conducting 'embedded' research. We suggest that reflexivity is an important concept for health system researchers who need to think carefully about positionality and their normative stance and to use such reflection to ensure that they can negotiate to retain autonomy, whilst also contributing evidence for health system change. A research process informed by the notion of reflexive practice and iterative learning will require a longitudinal review at key points in the research timeline. Such review should include the convening of a deliberative process and should involve a range of stakeholders, including those most likely to be affected by the intended and unintended consequences of change. © 2016 The Authors Developing World Bioethics Published by John Wiley & Sons Ltd.

  16. Will Global Climate Change Alter Fundamental Human Immune Reactivity: Implications for Child Health?

    Science.gov (United States)

    Swaminathan, Ashwin; Lucas, Robyn M; Harley, David; McMichael, Anthony J

    2014-11-11

    The human immune system is an interface across which many climate change sensitive exposures can affect health outcomes. Gaining an understanding of the range of potential effects that climate change could have on immune function will be of considerable importance, particularly for child health, but has, as yet, received minimal research attention. We postulate several mechanisms whereby climate change sensitive exposures and conditions will subtly impair aspects of the human immune response, thereby altering the distribution of vulnerability within populations-particularly for children-to infection and disease. Key climate change-sensitive pathways include under-nutrition, psychological stress and exposure to ambient ultraviolet radiation, with effects on susceptibility to infection, allergy and autoimmune diseases. Other climate change sensitive exposures may also be important and interact, either additively or synergistically, to alter health risks. Conducting directed research in this area is imperative as the potential public health implications of climate change-induced weakening of the immune system at both individual and population levels are profound. This is particularly relevant for the already vulnerable children of the developing world, who will bear a disproportionate burden of future adverse environmental and geopolitical consequences of climate change.

  17. Will Global Climate Change Alter Fundamental Human Immune Reactivity: Implications for Child Health?

    Directory of Open Access Journals (Sweden)

    Ashwin Swaminathan

    2014-11-01

    Full Text Available The human immune system is an interface across which many climate change sensitive exposures can affect health outcomes. Gaining an understanding of the range of potential effects that climate change could have on immune function will be of considerable importance, particularly for child health, but has, as yet, received minimal research attention. We postulate several mechanisms whereby climate change sensitive exposures and conditions will subtly impair aspects of the human immune response, thereby altering the distribution of vulnerability within populations—particularly for children—to infection and disease. Key climate change-sensitive pathways include under-nutrition, psychological stress and exposure to ambient ultraviolet radiation, with effects on susceptibility to infection, allergy and autoimmune diseases. Other climate change sensitive exposures may also be important and interact, either additively or synergistically, to alter health risks. Conducting directed research in this area is imperative as the potential public health implications of climate change-induced weakening of the immune system at both individual and population levels are profound. This is particularly relevant for the already vulnerable children of the developing world, who will bear a disproportionate burden of future adverse environmental and geopolitical consequences of climate change.

  18. Job crafting in changing organizations: Antecedents and implications for exhaustion and performance.

    Science.gov (United States)

    Petrou, Paraskevas; Demerouti, Evangelia; Schaufeli, Wilmar B

    2015-10-01

    The present study addressed employee job crafting behaviors (i.e., seeking resources, seeking challenges, and reducing demands) in the context of organizational change. We examined predictors of job crafting both at the organizational level (i.e., perceived impact of the implemented changes on the working life of employees) and the individual level (i.e., employee willingness to follow the changes). Job crafting behaviors were expected to predict task performance and exhaustion. Two-wave longitudinal data from 580 police officers undergoing organizational changes were analyzed with structural equation modeling. Findings showed that the degree to which changes influence employees' daily work was linked to reducing demands and exhaustion, whereas employee willingness to change was linked to seeking resources and seeking challenges. Furthermore, while seeking resources and seeking challenges were associated with high task performance and low exhaustion respectively, reducing demands seemed to predict exhaustion positively. Our findings suggest that job crafting can act as a strategy of employees to respond to organizational change. While seeking resources and seeking challenges enhance employee adjustment and should be encouraged by managers, reducing demands seems to have unfavorable implications for employees. (c) 2015 APA, all rights reserved).

  19. Selected physical, biological and biogeochemical implications of a rapidly changing Arctic Marginal Ice Zone

    Science.gov (United States)

    Barber, David G.; Hop, Haakon; Mundy, Christopher J.; Else, Brent; Dmitrenko, Igor A.; Tremblay, Jean-Eric; Ehn, Jens K.; Assmy, Philipp; Daase, Malin; Candlish, Lauren M.; Rysgaard, Søren

    2015-12-01

    The Marginal Ice Zone (MIZ) of the Arctic Ocean is changing rapidly due to a warming Arctic climate with commensurate reductions in sea ice extent and thickness. This Pan-Arctic review summarizes the main changes in the Arctic ocean-sea ice-atmosphere (OSA) interface, with implications for primary- and secondary producers in the ice and the underlying water column. Changes in the Arctic MIZ were interpreted for the period 1979-2010, based on best-fit regressions for each month. Trends of increasingly open water were statistically significant for each month, with quadratic fit for August-November, illustrating particularly strong seasonal feedbacks in sea-ice formation and decay. Geographic interpretations of physical and biological changes were based on comparison of regions with significant changes in sea ice: (1) The Pacific Sector of the Arctic Ocean including the Canada Basin and the Beaufort, Chukchi and East Siberian seas; (2) The Canadian Arctic Archipelago; (3) Baffin Bay and Hudson Bay; and (4) the Barents and Kara seas. Changes in ice conditions in the Barents sea/Kara sea region appear to be primarily forced by ocean heat fluxes during winter, whereas changes in the other sectors appear to be more summer-autumn related and primarily atmospherically forced. Effects of seasonal and regional changes in OSA-system with regard to increased open water were summarized for photosynthetically available radiation, nutrient delivery to the euphotic zone, primary production of ice algae and phytoplankton, ice-associated fauna and zooplankton, and gas exchange of CO2. Changes in the physical factors varied amongst regions, and showed direct effects on organisms linked to sea ice. Zooplankton species appear to be more flexible and likely able to adapt to variability in the onset of primary production. The major changes identified for the ice-associated ecosystem are with regard to production timing and abundance or biomass of ice flora and fauna, which are related to

  20. The treat of global climate change has important implications throughout the world

    International Nuclear Information System (INIS)

    Hejazi, R.

    2008-01-01

    Energy in general is essential for economic and social development, prosperity, health and security of citizens. of the other hand, world population over the last 10 years has increased by more than 12%, and now it is exactly about 6.4 billion people and it means more demand for energy. Meanwhile, global primary energy consumption has seen an increase of 20%. Energy supply has some sources and unfortunately most of them have impact on life cycle in biosphere. However, the developed countries, that are only 16% in the population in 2000, consume the energy of 80%. This article deals with the threat of global climate change and its implications throughout the world

  1. DNA excision repair in permeable human fibroblasts

    International Nuclear Information System (INIS)

    Kaufmann, W.K.; Bodell, W.J.; Cleaver, J.E.

    1983-01-01

    U.v. irradiation of confluent human fibroblasts activated DNA repair, aspects of which were characterized in the cells after they were permeabilized. Incubation of intact cells for 20 min between irradiation and harvesting was necessary to obtain a maximum rate of reparative DNA synthesis. Cells harvested immediately after irradiation before repair was initiated displayed only a small stimulation of DNA synthesis, indicating that permeable cells have a reduced capacity to recognize pyrimidine dimers and activate repair. The distribution of sizes of DNA strands labeled during 10 min of reparative DNA synthesis resembled that of parental DNA. However, during a 60-min incubation of permeable cells at 37 degrees C, parental DNA and DNA labeled by reparative DNA synthesis were both cleaved to smaller sizes. Cleavage also occurred in unirradiated cells, indicating that endogenous nuclease was active during incubation. Repair patches synthesized in permeable cells displayed increased sensitivity to digestion by micrococcal nuclease. However, the change in sensitivity during a chase with unlabeled DNA precursors was small, suggesting that reassembly of nucleosome structure at sites of repair was impaired. To examine whether this deficiency was due to a preponderance of incomplete or unligated repair patches, 3H-labeled (repaired) DNA was purified, then digested with exonuclease III and nuclease S1 to probe for free 3' ends and single-stranded regions. About 85% of the [3H]DNA synthesized during a 10-min pulse resisted digestion, suggesting that a major fraction of the repair patches that were filled were also ligated. U.v. light-activated DNA synthesis in permeable cells, therefore, appears to represent the continuation of reparative gap-filling at sites of excision repair activated within intact cells. Gap-filling and ligation were comparatively efficient processes in permeable cells

  2. Permeability testing of biomaterial membranes

    Energy Technology Data Exchange (ETDEWEB)

    Dreesmann, L; Hajosch, R; Nuernberger, J Vaz; Schlosshauer, B [NMI Natural and Medical Sciences Institute at University Tuebingen, Markwiesenstr. 55, D-72770 Reutlingen (Germany); Ahlers, M [GELITA AG, Gammelsbacher Str. 2, D-69412 Eberbach (Germany)], E-mail: schlosshauer@nmi.de

    2008-09-01

    The permeability characteristics of biomaterials are critical parameters for a variety of implants. To analyse the permeability of membranes made from crosslinked ultrathin gelatin membranes and the transmigration of cells across the membranes, we combined three technical approaches: (1) a two-chamber-based permeability assay, (2) cell culturing with cytochemical analysis and (3) biochemical enzyme electrophoresis (zymography). Based on the diffusion of a coloured marker molecule in conjunction with photometric quantification, permeability data for a gelatin membrane were determined in the presence or absence of gelatin degrading fibroblasts. Cytochemical evaluation after cryosectioning of the membranes was used to ascertain whether fibroblasts had infiltrated the membrane inside. Zymography was used to investigate the potential release of proteases from fibroblasts, which are known to degrade collagen derivatives such as gelatin. Our data show that the diffusion equilibrium of a low molecular weight dye across the selected gelatin membrane is approached after about 6-8 h. Fibroblasts increase the permeability due to cavity formation in the membrane inside without penetrating the membrane for an extended time period (>21 days in vitro). Zymography indicates that cavity formation is most likely due to the secretion of matrix metalloproteinases. In summary, the combination of the depicted methods promises to facilitate a more rational development of biomaterials, because it provides a rapid means of determining permeability characteristics and bridges the gap between descriptive methodology and the mechanistic understanding of permeability alterations due to biological degradation.

  3. Permeability testing of biomaterial membranes

    International Nuclear Information System (INIS)

    Dreesmann, L; Hajosch, R; Nuernberger, J Vaz; Schlosshauer, B; Ahlers, M

    2008-01-01

    The permeability characteristics of biomaterials are critical parameters for a variety of implants. To analyse the permeability of membranes made from crosslinked ultrathin gelatin membranes and the transmigration of cells across the membranes, we combined three technical approaches: (1) a two-chamber-based permeability assay, (2) cell culturing with cytochemical analysis and (3) biochemical enzyme electrophoresis (zymography). Based on the diffusion of a coloured marker molecule in conjunction with photometric quantification, permeability data for a gelatin membrane were determined in the presence or absence of gelatin degrading fibroblasts. Cytochemical evaluation after cryosectioning of the membranes was used to ascertain whether fibroblasts had infiltrated the membrane inside. Zymography was used to investigate the potential release of proteases from fibroblasts, which are known to degrade collagen derivatives such as gelatin. Our data show that the diffusion equilibrium of a low molecular weight dye across the selected gelatin membrane is approached after about 6-8 h. Fibroblasts increase the permeability due to cavity formation in the membrane inside without penetrating the membrane for an extended time period (>21 days in vitro). Zymography indicates that cavity formation is most likely due to the secretion of matrix metalloproteinases. In summary, the combination of the depicted methods promises to facilitate a more rational development of biomaterials, because it provides a rapid means of determining permeability characteristics and bridges the gap between descriptive methodology and the mechanistic understanding of permeability alterations due to biological degradation

  4. Mapping patterns of change in emotion-focused psychotherapy: Implications for theory, research, practice, and training.

    Science.gov (United States)

    Watson, Jeanne C

    2018-05-01

    An important objective in humanistic-experiential psychotherapies and particularly emotion-focused psychotherapy (EFT) is to map patterns of change. Effective mapping of the processes and pathways of change requires that in-session processes be linked to in-session resolutions, immediate post-session changes, intermediate outcome, final therapy outcome, and longer-term change. This is a challenging and long-term endeavour. Fine-grained descriptions of in-session processes that lead to resolution of specific interpersonal and intrapersonal issues linked with longer-term outcomes are the foundation of EFT, the process-experiential approach. In this paper, evidence in support of EFT as a treatment approach will be reviewed along with research on two mechanisms of change, viewed as central to EFT, clients' emotional processing and the therapeutic relationship conditions. The implications for psychotherapy research are discussed. Given the methodological constraints, there is a need for more innovative methodologies and strategies to investigate specific psychotherapy processes within and across different approaches to map patterns and mechanisms of change to enhance theory, research, practice, and training.

  5. Physiologically induced color-pattern changes in butterfly wings: mechanistic and evolutionary implications.

    Science.gov (United States)

    Otaki, Joji M

    2008-07-01

    A mechanistic understanding of the butterfly wing color-pattern determination can be facilitated by experimental pattern changes. Here I review physiologically induced color-pattern changes in nymphalid butterflies and their mechanistic and evolutionary implications. A type of color-pattern change can be elicited by elemental changes in size and position throughout the wing, as suggested by the nymphalid groundplan. These changes of pattern elements are bi-directional and bi-sided dislocation toward or away from eyespot foci and in both proximal and distal sides of the foci. The peripheral elements are dislocated even in the eyespot-less compartments. Anterior spots are more severely modified, suggesting the existence of an anterior-posterior gradient. In one species, eyespots are transformed into white spots with remnant-like orange scales, and such patterns emerge even at the eyespot-less "imaginary" foci. A series of these color-pattern modifications probably reveal "snap-shots" of a dynamic morphogenic signal due to heterochronic uncoupling between the signaling and reception steps. The conventional gradient model can be revised to account for these observed color-pattern changes.

  6. Climate Change Impacts on the Built Environment in the United States and Implications for Sustainability

    Science.gov (United States)

    Quattrochi, Dale A.

    2012-01-01

    As an integral part of the National Climate Assessment (NCA), technical assessment reports for 13 regions in the U.S. that describe the scientific rationale to support climate change impacts within the purview of these regions, and provide adaptation or mitigation measures in response to these impacts. These technical assessments focus on climate change impacts on sectors that are important environmental, biophysical, and social and economic aspects of sustainability within the U.S.: Climate change science, Ecosystems and biodiversity, Water resources, Human health, Energy supply and use, Water/energy/land use, Transportation, Urban/infrastructure/vulnerability, Agriculture, Impacts of climate change on tribal/indigenous and native lands and resources, Forestry, Land use/land cover change, Rural communities development, and Impacts on biogeochemical cycles, with implications for ecosystems and biodiversity. There is a critical and timely need for the development of mitigation and adaptation strategies in response to climate change by the policy and decision making communities, to insure resiliency and sustainability of the built environment in the future.

  7. Pollution abatement from road transport: cross-sectoral implications, climate co-benefits and behavioural change

    International Nuclear Information System (INIS)

    Oxley, T.; Elshkaki, A.; Kwiatkowski, L.; Castillo, A.; Scarbrough, T.; ApSimon, H.

    2012-01-01

    With the abatement potential of end-of-pipe technologies for road transport becoming increasingly marginal, and with greater emissions reductions still needed in order to reduce pollution, alternative strategies involving behavioural change and choices between fossil fuelled or low carbon vehicles becomes more important. The environmental requirements include local air quality objectives, meeting national emissions ceilings to limit transboundary effects, and to aspire to significant reductions in greenhouse gas emissions. In this paper we use the BRUTAL sub-model of the UK integrated Assessment Model (UKIAM) to investigate a selection of alternative strategies including downsizing of cars, switching from petrol to diesel, and the introduction of electric, bio-fuelled or hydrogen vehicles into the fleet, relative to a business-as-usual projection for 2020. Projected impacts upon air quality limit values, national emissions ceilings and CO 2 emissions are assessed in relation to local, national and international objectives. We discuss related life-cycle impacts, implications for infrastructure, and potential impacts upon emissions from other sectors in order to highlight the full potential implications of the different strategies within the context of changes resulting from other policy developments at different scales.

  8. Exploring the implications of social change for human development: perspectives, issues and future directions.

    Science.gov (United States)

    Chen, Xinyin

    2015-02-01

    Researchers have investigated the implications of social change for human development from different perspectives. The studies published in this special section were conducted within Greenfield's theoretical framework (2009). The findings concerning links between specific sociodemographic features (e.g., commercial activities, schooling) and individual cognition and social behaviour are particularly interesting because they tap the underlying forces that drive human development. To further understand the issues in these studies and in the field, a pluralist-constructive perspective is discussed, which emphasises the integration of diverse values and practices in both Western and non-Western societies and its effects on the development of sophisticated competencies in individual adaptation to the changing global community. In addition, several issues are highlighted and some suggestions are provided for future explorations in this field. © 2014 International Union of Psychological Science.

  9. CO2-vegetation feedbacks and other climate changes implicated in reducing base flow

    Science.gov (United States)

    Trancoso, Ralph; Larsen, Joshua R.; McVicar, Tim R.; Phinn, Stuart R.; McAlpine, Clive A.

    2017-03-01

    Changes in the hydrological cycle have a significant impact in water limited environments. Globally, some of these regions are experiencing declining precipitation yet are simultaneously becoming greener, partly due to vegetation feedbacks associated with increasing atmospheric CO2 concentrations. Reduced precipitation together with increasing rates of actual evapotranspiration diminishes streamflow, especially base flow, a critical freshwater dry-season resource. Here we assess recent changes in base flow in Australia from 1981-2013 and 1950-2013 and separate the contribution of precipitation, potential evapotranspiration, and other factors on base flow trends. Our findings reveal that these other factors influencing the base flow trends are best explained by an increase in photosynthetic activity. These results provide the first robust observational evidence that increasing atmospheric CO2 and its associated vegetation feedbacks are reducing base flow in addition to other climatic impacts. These findings have broad implications for water resource management, especially in the world's water limited regions.

  10. Geothermal Permeability Enhancement - Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Joe Beall; Mark Walters

    2009-06-30

    The overall objective is to apply known permeability enhancement techniques to reduce the number of wells needed and demonstrate the applicability of the techniques to other undeveloped or under-developed fields. The Enhanced Geothermal System (EGS) concept presented in this project enhances energy extraction from reduced permeability zones in the super-heated, vapor-dominated Aidlin Field of the The Geysers geothermal reservoir. Numerous geothermal reservoirs worldwide, over a wide temperature range, contain zones of low permeability which limit the development potential and the efficient recovery of heat from these reservoirs. Low permeability results from poorly connected fractures or the lack of fractures. The Enhanced Geothermal System concept presented here expands these technologies by applying and evaluating them in a systematic, integrated program.

  11. Response of the boreal forest ecosystem to climatic change and its silvicultural implications

    Energy Technology Data Exchange (ETDEWEB)

    Kellomaeki, S.; Haenninen, H.; Karjalainen, T. [Joensuu Univ. (Finland). Faculty of Forestry] [and others

    1996-12-31

    During the next 100 years, the mean annual temperature is expected to be 1-6 deg C higher than at present. It is also expected to be accompanied by a lengthening of the thermal growing season and increased precipitation. Consequently, climatic change will increase the uncertainty of the management of forest ecosystems in the future. In this context, this research project aimed to outline the ecological and silvicultural implications of climatic change with regard to (1) how the expected climatic change might modify the functioning and structure of the boreal forest ecosystem, and (2) how the silvicultural management of the forest ecosystem should be modified in order to maintain sustainable forest yield under changing climatic conditions. The experimental component of the project concerned first the effect that elevating temperature and elevating concentration of atmospheric carbon have on the ontogenetic development of Scots pine (Pinus sylvestris L) and on the subsequent increase in frost damage during winter. The second part of the study looked the effect of elevating temperature and elevating concentration of atmospheric carbon on the growth of Scots pine through photosynthesis, respiration, transpiration, nutrient supply, and changes in crown structure. This experiment was utilised in several subprojects of the overall project

  12. Weaning at Anglo-Saxon Raunds: Implications for changing breastfeeding practice in Britain over two millennia.

    Science.gov (United States)

    Haydock, Hannah; Clarke, Leon; Craig-Atkins, Elizabeth; Howcroft, Rachel; Buckberry, Jo

    2013-08-01

    This study investigated stable-isotope ratio evidence of weaning for the late Anglo-Saxon population of Raunds Furnells, Northamptonshire, UK. δ(15)N and δ(13)C values in rib collagen were obtained for individuals of different ages to assess the weaning age of infants within the population. A peak in δ(15) N values at about 2-year-old, followed by a decline in δ(15) N values until age three, indicates a change in diet at that age. This change in nitrogen isotope ratios corresponds with the mortality profile from the site, as well as with archaeological and documentary evidence on attitudes towards juveniles in the Anglo-Saxon period. The pattern of δ(13) C values was less clear. Comparison of the predicted age of weaning to published data from sites dating from the Iron Age to the 19th century in Britain reveals a pattern of changing weaning practices over time, with increasingly earlier commencement and shorter periods of complementary feeding in more recent periods. Such a change has implications for the interpretation of socioeconomic changes during this period of British history, since earlier weaning is associated with decreased birth spacing, and could thus have contributed to population growth. Copyright © 2013 Wiley Periodicals, Inc.

  13. Response of the boreal forest ecosystem to climatic change and its silvicultural implications

    Energy Technology Data Exchange (ETDEWEB)

    Kellomaeki, S; Haenninen, H; Karjalainen, T [Joensuu Univ. (Finland). Faculty of Forestry; and others

    1997-12-31

    During the next 100 years, the mean annual temperature is expected to be 1-6 deg C higher than at present. It is also expected to be accompanied by a lengthening of the thermal growing season and increased precipitation. Consequently, climatic change will increase the uncertainty of the management of forest ecosystems in the future. In this context, this research project aimed to outline the ecological and silvicultural implications of climatic change with regard to (1) how the expected climatic change might modify the functioning and structure of the boreal forest ecosystem, and (2) how the silvicultural management of the forest ecosystem should be modified in order to maintain sustainable forest yield under changing climatic conditions. The experimental component of the project concerned first the effect that elevating temperature and elevating concentration of atmospheric carbon have on the ontogenetic development of Scots pine (Pinus sylvestris L) and on the subsequent increase in frost damage during winter. The second part of the study looked the effect of elevating temperature and elevating concentration of atmospheric carbon on the growth of Scots pine through photosynthesis, respiration, transpiration, nutrient supply, and changes in crown structure. This experiment was utilised in several subprojects of the overall project

  14. Upscaling verticle permeability within a fluvio-aeolian reservoir

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, S.D.; Corbett, P.W.M.; Jensen, J.L. [Heriot-Watt Univ., Edinburgh (United Kingdom)

    1997-08-01

    Vertical permeability (k{sub v}) is a crucial factor in many reservoir engineering issues. To date there has been little work undertaken to understand the wide variation of k{sub v} values measured at different scales in the reservoir. This paper presents the results of a study in which we have modelled the results of a downhole well tester using a statistical model and high resolution permeability data. The work has demonstrates and quantifies a wide variation in k{sub v} at smaller, near wellbore scales and has implications for k{sub v} modelling at larger scales.

  15. Atrial natriuretic factor increases vascular permeability

    International Nuclear Information System (INIS)

    Lockette, W.; Brennaman, B.

    1990-01-01

    An increase in central blood volume in microgravity may result in increased plasma levels of atrial natriuretic factor (ANF). Since elevations in plasma ANF are found in clinical syndromes associated with edema, and since space motion sickness induced by microgravity is associated with an increase in central blood volume and facial edema, we determined whether ANF increases capillary permeability to plasma protein. Conscious, bilaterally nephrectomized male rats were infused with either saline, ANF + saline, or hexamethonium + saline over 2 h following bolus injections of 125I-albumin and 14C-dextran of similar molecular size. Blood pressure was monitored and serial determinations of hematocrits were made. Animals infused with 1.0 micrograms.kg-1.min-1 ANF had significantly higher hematocrits than animals infused with saline vehicle. Infusion of ANF increased the extravasation of 125I-albumin, but not 14C-dextran from the intravascular compartment. ANF also induced a depressor response in rats, but the change in blood pressure did not account for changes in capillary permeability to albumin; similar depressor responses induced by hexamethonium were not accompanied by increased extravasation of albumin from the intravascular compartment. ANF may decrease plasma volume by increasing permeability to albumin, and this effect of ANF may account for some of the signs and symptoms of space motion sickness

  16. Climate change risks and conservation implications for a threatened small-range mammal species.

    Science.gov (United States)

    Morueta-Holme, Naia; Fløjgaard, Camilla; Svenning, Jens-Christian

    2010-04-29

    Climate change is already affecting the distributions of many species and may lead to numerous extinctions over the next century. Small-range species are likely to be a special concern, but the extent to which they are sensitive to climate is currently unclear. Species distribution modeling, if carefully implemented, can be used to assess climate sensitivity and potential climate change impacts, even for rare and cryptic species. We used species distribution modeling to assess the climate sensitivity, climate change risks and conservation implications for a threatened small-range mammal species, the Iberian desman (Galemys pyrenaicus), which is a phylogenetically isolated insectivore endemic to south-western Europe. Atlas data on the distribution of G. pyrenaicus was linked to data on climate, topography and human impact using two species distribution modeling algorithms to test hypotheses on the factors that determine the range for this species. Predictive models were developed and projected onto climate scenarios for 2070-2099 to assess climate change risks and conservation possibilities. Mean summer temperature and water balance appeared to be the main factors influencing the distribution of G. pyrenaicus. Climate change was predicted to result in significant reductions of the species' range. However, the severity of these reductions was highly dependent on which predictor was the most important limiting factor. Notably, if mean summer temperature is the main range determinant, G. pyrenaicus is at risk of near total extinction in Spain under the most severe climate change scenario. The range projections for Europe indicate that assisted migration may be a possible long-term conservation strategy for G. pyrenaicus in the face of global warming. Climate change clearly poses a severe threat to this illustrative endemic species. Our findings confirm that endemic species can be highly vulnerable to a warming climate and highlight the fact that assisted migration has

  17. Climate change risks and conservation implications for a threatened small-range mammal species.

    Directory of Open Access Journals (Sweden)

    Naia Morueta-Holme

    Full Text Available BACKGROUND: Climate change is already affecting the distributions of many species and may lead to numerous extinctions over the next century. Small-range species are likely to be a special concern, but the extent to which they are sensitive to climate is currently unclear. Species distribution modeling, if carefully implemented, can be used to assess climate sensitivity and potential climate change impacts, even for rare and cryptic species. METHODOLOGY/PRINCIPAL FINDINGS: We used species distribution modeling to assess the climate sensitivity, climate change risks and conservation implications for a threatened small-range mammal species, the Iberian desman (Galemys pyrenaicus, which is a phylogenetically isolated insectivore endemic to south-western Europe. Atlas data on the distribution of G. pyrenaicus was linked to data on climate, topography and human impact using two species distribution modeling algorithms to test hypotheses on the factors that determine the range for this species. Predictive models were developed and projected onto climate scenarios for 2070-2099 to assess climate change risks and conservation possibilities. Mean summer temperature and water balance appeared to be the main factors influencing the distribution of G. pyrenaicus. Climate change was predicted to result in significant reductions of the species' range. However, the severity of these reductions was highly dependent on which predictor was the most important limiting factor. Notably, if mean summer temperature is the main range determinant, G. pyrenaicus is at risk of near total extinction in Spain under the most severe climate change scenario. The range projections for Europe indicate that assisted migration may be a possible long-term conservation strategy for G. pyrenaicus in the face of global warming. CONCLUSIONS/SIGNIFICANCE: Climate change clearly poses a severe threat to this illustrative endemic species. Our findings confirm that endemic species can be

  18. Farmers’ Adaptation Strategies to Climate Change and Their Implications in the Zou Department of South Benin

    Directory of Open Access Journals (Sweden)

    Adégnandjou Mahouna Roland Fadina

    2018-01-01

    Full Text Available Climate change is a global phenomenon. Its impact on agricultural activities in developing countries has increased dramatically. Understanding how farmers perceive climate change and how they adapt to it is very important to the implementation of adequate policies for agricultural and food security. This paper aims to contribute to an understanding of farmers’ adaptation choices, determinants of the adaptation choices and the long-term implications of the adaptation choices. Data were collected from 120 respondents in the Zou Department of Benin. A binary logit model was used to analyze the factors influencing household decisions to adapt to climate change. Multinomial logistic regression analysis was estimated to analyze the factors influencing households’ choice of adaptation strategies to climate change. The results show that farmers have a developed perception of climate change. These changes are translated by rainfall disturbances (rainfall delays, early cessation, bad rainfall distribution etc., shortening of the small dry season, increasing of temperature and sometimes, violent winds. The survey reveals that Benin farmers adopt many strategies in response to climate change. These strategies include “Crop–livestock diversification and other good practices (mulching, organic fertilizer,” “Use of improved varieties, chemical fertilizers and pesticides,” “Agroforestry and perennial plantation” and “Diversification of income-generating activities.” The findings also reveal that most of the respondents use these strategies in combination. From the binary logit model, we know that “farming experience” and “educational level of household head” positively influence adaptation decisions. The result of the multinomial logit analysis shows that farming experience, educational level, farm size and gender have a significant impact on climate change adaptation strategies. Based on in-depth analysis of each strategy, we

  19. Permeability of cork to gases.

    Science.gov (United States)

    Faria, David P; Fonseca, Ana L; Pereira, Helen; Teodoro, Orlando M N D

    2011-04-27

    The permeability of gases through uncompressed cork was investigated. More than 100 samples were assessed from different plank qualities to provide a picture of the permeability distribution. A novel technique based on a mass spectrometer leak detector was used to directly measure the helium flow through the central area of small disks 10 mm in diameter and 2 mm thick. The permeability for nitrogen, oxygen, and other gases was measured by the pressure rise technique. Boiled and nonboiled cork samples from different sections were evaluated. An asymmetric frequency distribution ranging 3 orders of magnitude (roughly from 1 to 1000 μmol/(cm·atm·day)) for selected samples without macroscopic defects was found, having a peak below 100 μmol/(cm·atm·day). Correlation was found between density and permeability: higher density samples tend to show lower permeability. However, boiled cork showed a mean lower permeability despite having a lower density. The transport mechanism of gases through cork was also examined. Calculations suggest that gases permeate uncompressed cork mainly through small channels between cells under a molecular flow regime. The diameter of such channels was estimated to be in the range of 100 nm, in agreement with the plasmodesmata size in the cork cell walls.

  20. Fracture permeability under effect of normal and shear stress: A preliminary experimental investigation

    International Nuclear Information System (INIS)

    Mohanty, S.; Manteufel, R.D.; Chowdhury, A.H.

    1995-01-01

    The change in fracture permeability under mechanical loads have been investigated. An apparatus has been developed to measure change in fracture permeability, when a single fracture is subjected to normal and shear stress. Both radial and linear flow experiments have been conducted by modifying a direct shear test apparatus. Preliminary results suggest a 35-percent change in fracture permeability under normal stress to 8 MPa and nearly 350 percent under shear displacement of 9.9254 m (1 in.) at 5 MPa normal stress. Effort is underway to separate the permeability change due to gouge material production from that of due to dilation

  1. Permeability of WIPP Salt During Damage Evolution and Healing

    International Nuclear Information System (INIS)

    BODNER, SOL R.; CHAN, KWAI S.; MUNSON, DARRELL E.

    1999-01-01

    The presence of damage in the form of microcracks can increase the permeability of salt. In this paper, an analytical formulation of the permeability of damaged rock salt is presented for both initially intact and porous conditions. The analysis shows that permeability is related to the connected (i.e., gas accessible) volumetric strain and porosity according to two different power-laws, which may be summed to give the overall behavior of a porous salt with damage. This relationship was incorporated into a constitutive model, known as the Multimechanism Deformation Coupled Fracture (MDCF) model, which has been formulated to describe the inelastic flow behavior of rock salt due to coupled creep, damage, and healing. The extended model was used to calculate the permeability of rock salt from the Waste Isolation Pilot Plant (WIPP) site under conditions where damage evolved with stress over a time period. Permeability changes resulting from both damage development under deviatoric stresses and damage healing under hydrostatic pressures were considered. The calculated results were compared against experimental data from the literature, which indicated that permeability in damaged intact WIPP salt depends on the magnitude of the gas accessible volumetric strain and not on the total volumetric strain. Consequently, the permeability of WIPP salt is significantly affected by the kinetics of crack closure, but shows little dependence on the kinetics of crack removal by sintering

  2. Cognition-emotion interactions: patterns of change and implications for math problem solving

    Science.gov (United States)

    Trezise, Kelly; Reeve, Robert A.

    2014-01-01

    Surprisingly little is known about whether relationships between cognitive and emotional states remain stable or change over time, or how different patterns of stability and/or change in the relationships affect problem solving abilities. Nevertheless, cross-sectional studies show that anxiety/worry may reduce working memory (WM) resources, and the ability to minimize the effects anxiety/worry is higher in individuals with greater WM capacity. To investigate the patterns of stability and/or change in cognition-emotion relations over time and their implications for problem solving, 126 14-year-olds’ algebraic WM and worry levels were assessed twice in a single day before completing an algebraic math problem solving test. We used latent transition analysis to identify stability/change in cognition-emotion relations, which yielded a six subgroup solution. Subgroups varied in WM capacity, worry, and stability/change relationships. Among the subgroups, we identified a high WM/low worry subgroup that remained stable over time and a high WM/high worry, and a moderate WM/low worry subgroup that changed to low WM subgroups over time. Patterns of stability/change in subgroup membership predicted algebraic test results. The stable high WM/low worry subgroup performed best and the low WM capacity-high worry “unstable across time” subgroup performed worst. The findings highlight the importance of assessing variations in cognition-emotion relationships over time (rather than assessing cognition or emotion states alone) to account for differences in problem solving abilities. PMID:25132830

  3. Cognition-emotion interactions: Patterns of change and implications for math problem solving

    Directory of Open Access Journals (Sweden)

    Kelly eTrezise

    2014-07-01

    Full Text Available Surprisingly little is known about whether relationships between cognitive and emotional states remain stable or change over time, or how different patterns of stability and/or change in the relationships affect problem solving abilities. Nevertheless, cross-sectional studies show that anxiety/worry may reduce working memory resources, and the ability to minimize the effects anxiety/worry is higher in individuals with greater WM capacity. To investigate the patterns of stability and/or change in cognition-emotion relations over time and their implications for problem solving, 126 14-year-olds’ algebraic WM and worry levels were assessed twice in a single day before completing an algebraic math problem solving test. We used latent transition analysis to identify stability/change in cognition-emotion relations, which yielded a six subgroup solution. Subgroups varied in WM capacity, worry, and stability/change relationships. Among the subgroups, we identified a high WM/low worry subgroup that remained stable over time and a high WM/high worry, and a moderate WM/low worry subgroup that changed to low WM subgroups over time. Patterns of stability/change in subgroup membership predicted algebraic test results. The stable high WM/low worry subgroup performed best and the low WM capacity-high worry unstable across time subgroup performed worst. The findings highlight the importance of assessing variations in cognition-emotion relationships over time (rather than assessing cognition or emotion states alone to account for differences in problem solving abilities.

  4. Implications of Climate Change for Northern Canada: Freshwater, Marine, and Terrestrial Ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    Prowse, Terry D.; Wrona, Fred J. (Water and Climate Impacts Research Centre, Environment Canada, Dept. of Geography, Univ. of Victoria, Victoria, BC (Canada)). e-mail: terry.prowse@ec.gc.caa; Furgal, Chris (Indigenous Environmental Studies Program, Trent Univ., Peterborough, ON (Canada)); Reist, James D. (Fisheries and Oceans Canada, 501 Univ. Crescent, Winnipeg, MB (Canada))

    2009-07-15

    Climate variability and change is projected to have significant effects on the physical, chemical, and biological components of northern Canadian marine, terrestrial, and freshwater systems. As the climate continues to change, there will be consequences for biodiversity shifts and for the ranges and distribution of many species with resulting effects on availability, accessibility, and quality of resources upon which human populations rely. This will have implications for the protection and management of wildlife, fish, and fisheries resources; protected areas; and forests. The northward migration of species and the disruption and competition from invading species are already occurring and will continue to affect marine, terrestrial, and freshwater communities. Shifting environmental conditions will likely introduce new animal-transmitted diseases and redistribute some existing diseases, affecting key economic resources and some human populations. Stress on populations of iconic wildlife species, such as the polar bear, ringed seals, and whales, will continue as a result of changes in critical sea-ice habitat interactions. Where these stresses affect economically and culturally important species, they will have significant effects on people and regional economies. Further integrated, field-based monitoring and research programs, and the development of predictive models are required to allow for more detailed and comprehensive projections of change to be made, and to inform the development and implementation of appropriate adaptation, wildlife, and habitat conservation and protection strategies

  5. Stratospheric ozone changes under solar geoengineering: implications for UV exposure and air quality

    Directory of Open Access Journals (Sweden)

    P. J. Nowack

    2016-03-01

    Full Text Available Various forms of geoengineering have been proposed to counter anthropogenic climate change. Methods which aim to modify the Earth's energy balance by reducing insolation are often subsumed under the term solar radiation management (SRM. Here, we present results of a standard SRM modelling experiment in which the incoming solar irradiance is reduced to offset the global mean warming induced by a quadrupling of atmospheric carbon dioxide. For the first time in an atmosphere–ocean coupled climate model, we include atmospheric composition feedbacks for this experiment. While the SRM scheme considered here could offset greenhouse gas induced global mean surface warming, it leads to important changes in atmospheric composition. We find large stratospheric ozone increases that induce significant reductions in surface UV-B irradiance, which would have implications for vitamin D production. In addition, the higher stratospheric ozone levels lead to decreased ozone photolysis in the troposphere. In combination with lower atmospheric specific humidity under SRM, this results in overall surface ozone concentration increases in the idealized G1 experiment. Both UV-B and surface ozone changes are important for human health. We therefore highlight that both stratospheric and tropospheric ozone changes must be considered in the assessment of any SRM scheme, due to their important roles in regulating UV exposure and air quality.

  6. Stratospheric ozone changes under solar geoengineering: implications for UV exposure and air quality

    Science.gov (United States)

    Nowack, Peer Johannes; Abraham, Nathan Luke; Braesicke, Peter; Pyle, John Adrian

    2016-03-01

    Various forms of geoengineering have been proposed to counter anthropogenic climate change. Methods which aim to modify the Earth's energy balance by reducing insolation are often subsumed under the term solar radiation management (SRM). Here, we present results of a standard SRM modelling experiment in which the incoming solar irradiance is reduced to offset the global mean warming induced by a quadrupling of atmospheric carbon dioxide. For the first time in an atmosphere-ocean coupled climate model, we include atmospheric composition feedbacks for this experiment. While the SRM scheme considered here could offset greenhouse gas induced global mean surface warming, it leads to important changes in atmospheric composition. We find large stratospheric ozone increases that induce significant reductions in surface UV-B irradiance, which would have implications for vitamin D production. In addition, the higher stratospheric ozone levels lead to decreased ozone photolysis in the troposphere. In combination with lower atmospheric specific humidity under SRM, this results in overall surface ozone concentration increases in the idealized G1 experiment. Both UV-B and surface ozone changes are important for human health. We therefore highlight that both stratospheric and tropospheric ozone changes must be considered in the assessment of any SRM scheme, due to their important roles in regulating UV exposure and air quality.

  7. Changes of wood anatomical characters of selected species of Araucaria- during artificial charring - implications for palaeontology

    Directory of Open Access Journals (Sweden)

    Isa Carla Osterkamp

    2017-11-01

    Full Text Available ABSTRACT Charcoal is widely accepted as evidence of the occurrence of palaeo-wildfire. Although fossil charcoal remains have been used in many studies, investigation into the anatomical changes occurring during charring are few. The present study analyses changes in selected anatomical characters during artificial charring of modern wood of three species of the genus Araucaria (i.e. Araucaria angustifolia, Araucaria bidwillii and Araucaria columnaris. Wood samples of the studied species was charred under controlled conditions at varying temperatures. Measurements of anatomical features of uncharred wood and artificial charcoal were statistically analysed. The anatomical changes were statistically correlated with charring temperatures and most of the parameters showed marked decreases with increasing charring temperature. Compared to the intrinsic variability in anatomical features, both within and between growth rings of an individual plant, the changes induced by temperature account only for a comparatively small percentage of the observed variability. Regarding Araucaria charcoal, it seems possible that at least general taxonomic and palaeoenvironmental implications can be drawn from such material. However, it is not clear so far whether these results and interpretations based on only three taxa, can be generalized for the entire family and anatomically similar fossil taxa or not.

  8. DECOVALEX-THMC Task D: Long-Term Permeability/Porosity Changes in the EDZ and Near Field due to THM and THC Processes in Volcanic and Crystalline-Bentonite Systems, Status Report October 2005

    International Nuclear Information System (INIS)

    Birkholzer, J.; Rutqvist, J.; Sonnenthal, E.; Barr, D.

    2005-01-01

    The DECOVALEX project is an international cooperative project initiated by SKI, the Swedish Nuclear Power Inspectorate, with participation of about 10 international organizations. The name DECOVALEX stands for DEvelopment of COupled models and their VALidation against Experiments. The general goal of this project is to encourage multidisciplinary interactive and cooperative research on modeling coupled processes in geologic formations in support of the performance assessment for underground storage of radioactive waste. Three multi-year project stages of DECOVALEX have been completed in the past decade, mainly focusing on coupled thermal-hydrological-mechanical processes. Currently, a fourth three-year project stage of DECOVALEX is under way, referred to as DECOVALEX-THMC. THMC stands for Thermal, Hydrological, Mechanical, and Chemical processes. The new project stage aims at expanding the traditional geomechanical scope of the previous DECOVALEX project stages by incorporating geochemical processes important for repository performance. The U.S. Department of Energy (DOE) leads Task D of the new DECOVALEX phase, entitled ''Long-term Permeability/Porosity Changes in the EDZ and Near Field due to THC and THM Processes for Volcanic and Crystalline-Bentonite Systems''. In its leadership role for Task D, DOE coordinates and sets the direction for the cooperative research activities of the international research teams engaged in Task D

  9. Resistance of essential fatty acid-deficient rats to endotoxin-induced increases in vascular permeability

    International Nuclear Information System (INIS)

    Li, E.J.; Cook, J.A.; Spicer, K.M.; Wise, W.C.; Rokach, J.; Halushka, P.V.

    1990-01-01

    Resistance to endotoxin in essential fatty acid-deficient (EFAD) rats is associated with reduced synthesis of certain arachidonic acid metabolites. It was hypothesized that EFAD rats would manifest decreased vascular permeability changes during endotoxemia as a consequence of reduced arachidonic acid metabolism. To test this hypothesis, changes in hematocrit (HCT) and mesenteric localization rate of technetium-labeled human serum albumin (99mTc-HSA) and red blood cells (99mTc-RBC) were assessed in EFAD and normal rats using gamma-camera imaging. Thirty minutes after Salmonella enteritidis endotoxin, EFAD rats exhibited less hemoconcentration as determined by % HCT than normal rats. Endotoxin caused a less severe change in permeability index in the splanchnic region in EFAD rats than in normal rats (1.2 +/- 0.6 x 10(-3)min-1 vs. 4.9 +/- 1.7 x 10(-3)min-1 respectively, P less than 0.05). In contrast to 99mTc-HSA, mesenteric localization of 99mTc-RBC was not changed by endotoxin in control or EFAD rats. Supplementation with ethyl-arachidonic acid did not enhance susceptibility of EFAD rats to endotoxin-induced splanchnic permeability to 99mTc-HSA. Leukotrienes have been implicated as mediators of increased vascular permeability in endotoxin shock. Since LTC3 formation has been reported to be increased in EFA deficiency, we hypothesized that LTC3 may be less potent than LTC4. Thus the effect of LTC3 on mean arterial pressure and permeability was compared to LTC4 in normal rats. LTC3-induced increases in peak mean arterial pressure were less than LTC4 at 10 micrograms/kg (39 +/- 5 mm Hg vs. 58 +/- 4 mm Hg respectively, P less than 0.05) and at 20 micrograms/kg (56 +/- 4 mm Hg vs. 75 +/- 2 mm Hg respectively, P less than 0.05). LY171883 (30 mg/kg), an LTD4/E4 receptor antagonist, attenuated the pressor effect of LTC4, LTD4, and LTC3

  10. Permeability of different size waste particles

    Directory of Open Access Journals (Sweden)

    Sabina Gavelytė

    2015-10-01

    Full Text Available The world and life style is changing, but the most popular disposal route for waste is landfill globally until now. We have to think about waste prevention and preparing for re-use or recycling firstly, according to the waste disposal hierarchy. Disposed waste to the landfill must be the last opportunity. In a landfill, during waste degradation processes leachate is formed that can potentially cause clogging of bottom drainage layers. To ensure stability of a landfill construction, the physical properties of its components have to be controlled. The hydrology of precipitation, evaporation, runoff and the hydraulic performance of the capping and liner materials are important controls of the moisture content. The water balance depends also on the waste characteristics and waste particle size distribution. The aim of this paper is to determine the hydraulic permeability in a landfill depending on the particle size distribution of municipal solid waste disposed. The lab experiment results were compared with the results calculated with DEGAS model. Samples were taken from a landfill operated for five years. The samples particle sizes are: >100 mm, 80 mm, 60 mm, 40 mm, 20 mm, 0.01 mm and <0.01 mm. The permeability test was conducted using the column test. The paper presents the results of experiment and DEGAS model water permeability with waste particle size.

  11. Implication of the changing concept of genes on plant breeder’s work

    Directory of Open Access Journals (Sweden)

    Marco Aurélio D. Dias

    2011-01-01

    Full Text Available The recent genome sequencing of some species has accumulated evidence that for a large number of traits, thecontrol and action of genes are far more complex than previously thought. This article discusses possible implications of newinsights into the gene concept on the work of plant breeders. Apparently, the successful application of biotechnological techniques is not as simple as once assumed. The evident changes in the available concept of genes confirmed what the past experience had shown,i.e, selection should focus on the phenotype, under the same conditions as the plant is to be cultivated in. Advanced vocationaltraining of plant breeders must be continuously maintained, focusing on phenotype-based selection in as accurate as possibleexperiments.

  12. The changing structure of the international oil industry: implications for OPEC

    International Nuclear Information System (INIS)

    Abdalla, K.L.; )

    1995-01-01

    This paper examines the changes in international oil market structure observed in the 1980s and early 1990s and assesses possible effects on oil market conditions in the future and implications for OPEC. It focuses on the trend toward a more vertical organization mainly resulting from substantial purchases of downstream assets by state owned oil companies in major oil producing countries. While the Gulf war prevented greater horizontal concentration of oil reserves, it merely interrupted the trend toward vertical concentration in the international oil industry. The vertical integration of only some of the OPEC members will cause a further divergence of goals within the organization resulting in a lower likelihood of OPEC regaining its former position as an effective cartel. If the trend toward greater vertical concentration increases, future oil prices will, in part, be affected by decisions made by vertically integrated firms. (author)

  13. Change of MIT bag constant in nuclear medium and implication for the EMC effect

    International Nuclear Information System (INIS)

    Jin, X.; Jennings, B.K.

    1997-01-01

    The modified quark-meson coupling model, which features a density-dependent bag constant and bag radius in nuclear matter, is checked against the EMC effect within the framework of dynamical rescaling. Our emphasis is on the change in the average bag radius in nuclei, as evaluated in a local density approximation, and its implication for the rescaling parameter. We find that when the bag constant in nuclear matter is significantly reduced from its free-space value, the resulting rescaling parameter is in good agreement with that required to explain the observed depletion of the structure functions in the medium Bjorken x region. Such a large reduction of the bag constant also implies large and canceling Lorentz scalar and vector potentials for the nucleon in nuclear matter which are comparable to those suggested by the relativistic nuclear phenomenology and finite-density QCD sum rules. copyright 1997 The American Physical Society

  14. Effect of temperature on the permeability of gas adsorbed coal under triaxial stress conditions

    Science.gov (United States)

    Li, Xiangchen; Yan, Xiaopeng; Kang, Yili

    2018-04-01

    The combined effects of gas sorption, stress and temperature play a significant role in the changing behavior of gas permeability in coal seams. The effect of temperature on nitrogen and methane permeability of naturally fractured coal is investigated. Coal permeability, P-wave velocity and axial strain were simultaneously measured under two effective stresses and six different temperatures. The results showed that the behavior of nitrogen and methane permeability presented nonmonotonic changes with increasing temperature. The variation in the P-wave velocity and axial strain showed a good correspondence with coal permeability. A higher effective stress limited the bigger deformation and caused the small change in permeability. Methane adsorption and desorption significantly influence the mechanical properties of coal and play an important role in the variations in coal permeability. The result of coal permeability during a complete stress-strain process showed that the variation in permeability is determined by the evolution of the internal structure. The increase in the temperature of the gas saturated coal causes the complex interaction between matrix swelling, matrix shrinkage and micro-fracture generation, which leads to the complex changes in coal structure and permeability. These results are helpful to understand the gas transport mechanism for exploiting coal methane by heat injection.

  15. Diagenetic effect on permeabilities of geothermal sandstone reservoirs

    DEFF Research Database (Denmark)

    Weibel, Rikke; Olivarius, Mette; Kristensen, Lars

    The Danish subsurface contains abundant sedimentary deposits, which can be utilized for geothermal heating. The Upper Triassic – Lower Jurassic continental-marine sandstones of the Gassum Formation has been utilised as a geothermal reservoir for the Thisted Geothermal Plant since 1984 extracting...... and permeability is caused by increased diagenetic changes of the sandstones due to increased burial depth and temperatures. Therefore, the highest water temperatures typically correspond with the lowest porosities and permeabilities. Especially the permeability is crucial for the performance of the geothermal......-line fractures. Continuous thin chlorite coatings results in less porosity- and permeability-reduction with burial than the general reduction with burial, unless carbonate cemented. Therefore, localities of sandstones characterized by these continuous chlorite coatings may represent fine geothermal reservoirs...

  16. Sea-level rise caused by climate change and its implications for society

    Science.gov (United States)

    MIMURA, Nobuo

    2013-01-01

    Sea-level rise is a major effect of climate change. It has drawn international attention, because higher sea levels in the future would cause serious impacts in various parts of the world. There are questions associated with sea-level rise which science needs to answer. To what extent did climate change contribute to sea-level rise in the past? How much will global mean sea level increase in the future? How serious are the impacts of the anticipated sea-level rise likely to be, and can human society respond to them? This paper aims to answer these questions through a comprehensive review of the relevant literature. First, the present status of observed sea-level rise, analyses of its causes, and future projections are summarized. Then the impacts are examined along with other consequences of climate change, from both global and Japanese perspectives. Finally, responses to adverse impacts will be discussed in order to clarify the implications of the sea-level rise issue for human society. PMID:23883609

  17. Influence of smallholder farmers’ perceptions on adaptation strategies to climate change and policy implications in Zimbabwe

    Directory of Open Access Journals (Sweden)

    Jiri Obert

    2017-01-01

    Full Text Available Smallholder agricultural production is largely affected by climate change and variability. Despite the negative effects brought by climate variability, smallholder farmers are still able to derive livelihoods. An understanding of factors that influence farmers’ responses and adaptation to climate variability can improve decision making for governments and development partners. This study investigated farmers’ perceptions and adaptation strategies to climate change and how these influence adaptation policies at local level. A survey was conducted with 100 households randomly selected from Chiredzi district. Data collected was used to derive farmer perceptions to climate change as well as the influence of their perceptions and subsequent adaptation methods to ensuing local agricultural adaptation measures and policies. The results indicated that smallholder farmers perceived general reduction in long-term annual rainfall and rising local average temperatures. Adverse trends in rainfall and average temperature perceived by farmers were consistent with empirical data. These perceptions and other socio-economic factors helped to shape smallholder farmer agricultural adaptation strategies. Policy implications are that the government and development partners should seek ways to assist autonomous adaptations by farmers through investments in planned adaptation initiatives.

  18. Sea-level rise caused by climate change and its implications for society.

    Science.gov (United States)

    Mimura, Nobuo

    2013-01-01

    Sea-level rise is a major effect of climate change. It has drawn international attention, because higher sea levels in the future would cause serious impacts in various parts of the world. There are questions associated with sea-level rise which science needs to answer. To what extent did climate change contribute to sea-level rise in the past? How much will global mean sea level increase in the future? How serious are the impacts of the anticipated sea-level rise likely to be, and can human society respond to them? This paper aims to answer these questions through a comprehensive review of the relevant literature. First, the present status of observed sea-level rise, analyses of its causes, and future projections are summarized. Then the impacts are examined along with other consequences of climate change, from both global and Japanese perspectives. Finally, responses to adverse impacts will be discussed in order to clarify the implications of the sea-level rise issue for human society.(Communicated by Kiyoshi HORIKAWA, M.J.A.).

  19. Effects of climate change on streamflow extremes and implications for reservoir inflow in the United States

    International Nuclear Information System (INIS)

    Naz, Bibi S.; Kao, Shih-Chieh; Ashfaq, Moetasim; Gao, Huilin

    2017-01-01

    The magnitude and frequency of hydrometeorological extremes are expected to increase in the conterminous United States (CONUS) over the rest of this century, and their increase will significantly impact water resource management. While previous efforts focused on the effects of reservoirs on downstream discharge, the effects of climate change on reservoir inflows in upstream areas are not well understood. We evaluated the large-scale climate change effects on extreme hydrological events and their implications for reservoir inflows in 178 headwater basins across CONUS using the Variable Infiltration Capacity (VIC) hydrologic model. The VIC model was forced with a 10-member ensemble of global circulation models under the Representative Concentration Pathway 8.5 that were dynamically downscaled using a regional climate model (RegCM4) and bias-corrected to 1/24° grid cell resolution. The results projected an increase in the likelihood of flood risk by 44% for a majority of subbasins upstream of flood control reservoirs in the central United States and increased drought risk by 11% for subbasins upstream of hydropower reservoirs across the western United States. Increased risk of both floods and droughts can potentially make reservoirs across CONUS more vulnerable to future climate conditions. In conclusion, this study estimates reservoir inflow changes over the next several decades, which can be used to optimize water supply management downstream.

  20. Technological Innovation and Competitiveness in The Global Economy: India's Changing Status and Its Implications

    Directory of Open Access Journals (Sweden)

    Bala Subrahmanya Mungila Hillemane

    2013-09-01

    Full Text Available   This paper probes the changing innovation status and resultant competitiveness in the context of global economy and questions the recent ranking improvements of India on the basis of hard economic facts. This paper has made use of secondary data comprising innovation indices and competitiveness rankings published by international organizations and reputed business schools from time to time since 1996 to analyze the changing status of India internationally. Later, using secondary data on key macro-economic variables published by the Government of India, the recent ranking of India is closely examined as well as recent steps taken by the government of India to improve competitiveness is elaborated. The study throws light on the changing but improving innovation dimensions and competitiveness ranking of India since 1996 till 2010. From nowhere India emerges and occupies the second slot, after China, in the global competitiveness ranking. But hard core macro-economic variables do not justify India’s elevation to the top in any way. Given this, the study throws light on the recent policy measures announced by the Government of India and its implications as well as policy imperatives.

  1. Changes in Wine Ethanol Content Due to Evaporation from Wine Glasses and Implications for Sensory Analysis.

    Science.gov (United States)

    Wollan, David; Pham, Duc-Truc; Wilkinson, Kerry Leigh

    2016-10-12

    The relative proportion of water and ethanol present in alcoholic beverages can significantly influence the perception of wine sensory attributes. This study therefore investigated changes in wine ethanol concentration due to evaporation from wine glasses. The ethanol content of commercial wines exposed to ambient conditions while in wine glasses was monitored over time. No change in wine ethanol content was observed where glasses were covered with plastic lids, but where glasses were not covered, evaporation had a significant impact on wine ethanol content, with losses from 0.9 to 1.9% alcohol by volume observed for wines that received direct exposure to airflow for 2 h. Evaporation also resulted in decreases in the concentration of some fermentation volatiles (determined by gas chromatography-mass spectrometry) and a perceptible change in wine aroma. The rate of ethanol loss was strongly influenced by exposure to airflow (i.e., from the laboratory air-conditioning unit), together with certain glass shape and wine parameters; glass headspace in particular. This is the first study to demonstrate the significant potential for ethanol evaporation from wine in wine glasses. Research findings have important implications for the technical evaluation of wine sensory properties; in particular, informal sensory trials and wine show judging, where the use of covers on wine glasses is not standard practice.

  2. Alaska's Changing Fire Regime - Implications for the Vulnerability of Its Boreal Forests

    Science.gov (United States)

    Kasischke, E. S.; Hoy, E. E.; Verbyla, D. L.; Rupp, T. S.; Duffy, P. A.; McGuire, A. D.; Murphy, K. A.; Jandt, R.; Barnes, J. L.; Calef, M.; hide

    2010-01-01

    A synthesis was carried out to examine Alaska s boreal forest fire regime. During the 2000s, an average of 767 000 ha/year burned, 50% higher than in any previous decade since the 1940s. Over the past 60 years, there was a decrease in the number of lightning-ignited fires, an increase in extreme lightning-ignited fire events, an increase in human-ignited fires, and a decrease in the number of extreme human-ignited fire events. The fraction of area burned from humanignited fires fell from 26% for the 1950s and 1960s to 5% for the 1990s and 2000s, a result from the change in fire policy that gave the highest suppression priorities to fire events that occurred near human settlements. The amount of area burned during late-season fires increased over the past two decades. Deeper burning of surface organic layers in black spruce (Picea mariana (Mill.) BSP) forests occurred during late-growing-season fires and on more well-drained sites. These trends all point to black spruce forests becoming increasingly vulnerable to the combined changes of key characteristics of Alaska s fire regime, except on poorly drained sites, which are resistant to deep burning. The implications of these fire regime changes to the vulnerability and resilience of Alaska s boreal forests and land and fire management are discussed.

  3. Evidence and implications of recent and projected climate change in Alaska's forest ecosystems

    Science.gov (United States)

    Wolken, Jane M.; Hollingsworth, Teresa N.; Rupp, T. Scott; Chapin, Stuart III; Trainor, Sarah F.; Barrett, Tara M.; Sullivan, Patrick F.; McGuire, A. David; Euskirchen, Eugénie S.; Hennon, Paul E.; Beever, Erik A.; Conn, Jeff S.; Crone, Lisa K.; D'Amore, David V.; Fresco, Nancy; Hanley, Thomas A.; Kielland, Knut; Kruse, James J.; Patterson, Trista; Schuur, Edward A.G.; Verbyla, David L.; Yarie, John

    2011-01-01

    The structure and function of Alaska's forests have changed significantly in response to a changing climate, including alterations in species composition and climate feedbacks (e.g., carbon, radiation budgets) that have important regional societal consequences and human feedbacks to forest ecosystems. In this paper we present the first comprehensive synthesis of climate-change impacts on all forested ecosystems of Alaska, highlighting changes in the most critical biophysical factors of each region. We developed a conceptual framework describing climate drivers, biophysical factors and types of change to illustrate how the biophysical and social subsystems of Alaskan forests interact and respond directly and indirectly to a changing climate. We then identify the regional and global implications to the climate system and associated socio-economic impacts, as presented in the current literature. Projections of temperature and precipitation suggest wildfire will continue to be the dominant biophysical factor in the Interior-boreal forest, leading to shifts from conifer- to deciduous-dominated forests. Based on existing research, projected increases in temperature in the Southcentral- and Kenai-boreal forests will likely increase the frequency and severity of insect outbreaks and associated wildfires, and increase the probability of establishment by invasive plant species. In the Coastal-temperate forest region snow and ice is regarded as the dominant biophysical factor. With continued warming, hydrologic changes related to more rapidly melting glaciers and rising elevation of the winter snowline will alter discharge in many rivers, which will have important consequences for terrestrial and marine ecosystem productivity. These climate-related changes will affect plant species distribution and wildlife habitat, which have regional societal consequences, and trace-gas emissions and radiation budgets, which are globally important. Our conceptual framework facilitates

  4. Implications of land use change in tropical West Africa under global warming

    Science.gov (United States)

    Brücher, Tim; Claussen, Martin

    2015-04-01

    productive. Given the limitations of an ESM, the findings of our study show that changes in the kind and intensity of land use have minor effects on the climate. Consequently, implications of extreme land use on e.g. human security, conflict or migration can be investigated in offline simulations.

  5. Spatial-temporal changes of maximum and minimum temperatures in the Wei River Basin, China: Changing patterns, causes and implications

    Science.gov (United States)

    Liu, Saiyan; Huang, Shengzhi; Xie, Yangyang; Huang, Qiang; Leng, Guoyong; Hou, Beibei; Zhang, Ying; Wei, Xiu

    2018-05-01

    Due to the important role of temperature in the global climate system and energy cycles, it is important to investigate the spatial-temporal change patterns, causes and implications of annual maximum (Tmax) and minimum (Tmin) temperatures. In this study, the Cloud model were adopted to fully and accurately analyze the changing patterns of annual Tmax and Tmin from 1958 to 2008 by quantifying their mean, uniformity, and stability in the Wei River Basin (WRB), a typical arid and semi-arid region in China. Additionally, the cross wavelet analysis was applied to explore the correlations among annual Tmax and Tmin and the yearly sunspots number, Arctic Oscillation, Pacific Decadal Oscillation, and soil moisture with an aim to determine possible causes of annual Tmax and Tmin variations. Furthermore, temperature-related impacts on vegetation cover and precipitation extremes were also examined. Results indicated that: (1) the WRB is characterized by increasing trends in annual Tmax and Tmin, with a more evident increasing trend in annual Tmin, which has a higher dispersion degree and is less uniform and stable than annual Tmax; (2) the asymmetric variations of Tmax and Tmin can be generally explained by the stronger effects of solar activity (primarily), large-scale atmospheric circulation patterns, and soil moisture on annual Tmin than on annual Tmax; and (3) increasing annual Tmax and Tmin have exerted strong influences on local precipitation extremes, in terms of their duration, intensity, and frequency in the WRB. This study presents new analyses of Tmax and Tmin in the WRB, and the findings may help guide regional agricultural production and water resources management.

  6. Multiple stressors, nonlinear effects and the implications of climate change impacts on marine coastal ecosystems.

    Science.gov (United States)

    Hewitt, Judi E; Ellis, Joanne I; Thrush, Simon F

    2016-08-01

    Global climate change will undoubtedly be a pressure on coastal marine ecosystems, affecting not only species distributions and physiology but also ecosystem functioning. In the coastal zone, the environmental variables that may drive ecological responses to climate change include temperature, wave energy, upwelling events and freshwater inputs, and all act and interact at a variety of spatial and temporal scales. To date, we have a poor understanding of how climate-related environmental changes may affect coastal marine ecosystems or which environmental variables are likely to produce priority effects. Here we use time series data (17 years) of coastal benthic macrofauna to investigate responses to a range of climate-influenced variables including sea-surface temperature, southern oscillation indices (SOI, Z4), wind-wave exposure, freshwater inputs and rainfall. We investigate responses from the abundances of individual species to abundances of functional traits and test whether species that are near the edge of their tolerance to another stressor (in this case sedimentation) may exhibit stronger responses. The responses we observed were all nonlinear and some exhibited thresholds. While temperature was most frequently an important predictor, wave exposure and ENSO-related variables were also frequently important and most ecological variables responded to interactions between environmental variables. There were also indications that species sensitive to another stressor responded more strongly to weaker climate-related environmental change at the stressed site than the unstressed site. The observed interactions between climate variables, effects on key species or functional traits, and synergistic effects of additional anthropogenic stressors have important implications for understanding and predicting the ecological consequences of climate change to coastal ecosystems. © 2015 John Wiley & Sons Ltd.

  7. Implications of various land use change scenarios on global water scarcity over the 21st century

    Science.gov (United States)

    Liu, Y.; Hejazi, M. I.; Vernon, C. R.; Li, X.; Le Page, Y.; Calvin, K. V.

    2017-12-01

    While the effects of land use and land cover change (LULCC) on hydrological processes (e.g., runoff, peak flow and discharge) and water availability have been extensively researched, the impacts of LULCC on water scarcity has been rarely investigated. Water scarcity, usually defined as the ratio of water demand to available renewable water supply. The involved water demand is an important human-dimension factor, which is affected by both socio-economic conditions (e.g., population, income) as well as LULCC (e.g., the amount of land we dedicate for food, feed, and fuel crops). Recent studies have assessed the combined effects of climate change and human interventions (e.g., dams, water withdrawals and LULCC) on water scarcity, but none to date has focused on the implications of different pathways of LULCC alone on water scarcity. We establish a set of LULCC scenarios under changing climate and socioeconomic pathways using an integrated assessment model - Global Change Assessment Model (GCAM), which integrates natural systems (e.g., water supply, ecosystems, climate) and human systems (e.g., water demand, land use, economy, food, energy, population). The LULCC scenarios encompass varying degrees of protected areas, different magnitudes of crop/bioenergy production and subsidies, and whether to penalize potential land use emissions from bioenergy production (e.g., loss of wood carbon stock from land conversion). Then we investigate how water scarcity responds to LULCC and how the distribution of global population under severe water stress varies in the 21st century. Preliminary results indicate that the LULCC-induced changes in water scarcity are overall small at the global scale (water stress and population being affected. Findings from this research could be used to inform strategies focused on alleviating water stress around the world.

  8. Modification of permeability of frog perineurium to [14C]-sucrose by stretch and hypertonicity

    International Nuclear Information System (INIS)

    Weerasuriya, A.; Rapoport, S.I.; Taylor, R.E.

    1979-01-01

    An in vitro method has been developed to determine quantitatively the permeability of the perineurium to radiotracers at room temperature. The permeability to [ 14 C]sucrose of the isolated perineurium of the sciatic nerve of the frog, Rana pipiens, was measured at rest length, when the perineurium was stretched and after the perineurium had been subjected to hypertonic treatment. Mean permeability at rest length was calculated to be 5.6 +- 0.27 (S.E.M., n=45)x10 -7 cm/sec, and both stretch and hypertonic treatment increased the permeability. A 10% stretch increased permeability reversibly, whereas a 20% stretch or immersion of the perineurium in a hypertonic bath increased permeability irreversibly. Altered permeability under these conditions might be related to changes in the ultrastructure of tight junctions in the perineurium. (Auth.)

  9. Climate Change: Implications for the Assumptions, Goals and Methods of Urban Environmental Planning

    Directory of Open Access Journals (Sweden)

    Kristina Hill

    2016-12-01

    Full Text Available As a result of increasing awareness of the implications of global climate change, shifts are becoming necessary and apparent in the assumptions, concepts, goals and methods of urban environmental planning. This review will present the argument that these changes represent a genuine paradigm shift in urban environmental planning. Reflection and action to develop this paradigm shift is critical now and in the next decades, because environmental planning for cities will only become more urgent as we enter a new climate period. The concepts, methods and assumptions that urban environmental planners have relied on in previous decades to protect people, ecosystems and physical structures are inadequate if they do not explicitly account for a rapidly changing regional climate context, specifically from a hydrological and ecological perspective. The over-arching concept of spatial suitability that guided planning in most of the 20th century has already given way to concepts that address sustainability, recognizing the importance of temporality. Quite rapidly, the concept of sustainability has been replaced in many planning contexts by the priority of establishing resilience in the face of extreme disturbance events. Now even this concept of resilience is being incorporated into a novel concept of urban planning as a process of adaptation to permanent, incremental environmental changes. This adaptation concept recognizes the necessity for continued resilience to extreme events, while acknowledging that permanent changes are also occurring as a result of trends that have a clear direction over time, such as rising sea levels. Similarly, the methods of urban environmental planning have relied on statistical data about hydrological and ecological systems that will not adequately describe these systems under a new climate regime. These methods are beginning to be replaced by methods that make use of early warning systems for regime shifts, and process

  10. Internal versus external controls on age variability: Definitions, origins and implications in a changing climate

    Science.gov (United States)

    Harman, C. J.

    2015-12-01

    The unsteadiness of stream water age is now well established, but the controls on the age dynamics, and the adequate representation and prediction of those dynamics, are not. A basic distinction can be made between internal variability that arises from changes in the proportions of flow moving through the diverse flow pathways of a hydrologic system, and external variability that arises from the stochasticity of inputs and outputs (such as precipitation and streamflow). In this talk I will show how these two types of age variability can be formally defined and distinguished within the framework of rank StorAge Selection (rSAS) functions. Internal variability implies variations in time in the rSAS function, while external variability does not. This leads naturally to the definition of several modes of internal variability, reflecting generic ways that system flowpaths may be rearranged. This rearrangement may be induced by fluctuations in the system state (such as catchment wetness), or by longer-term changes in catchment structure (such as land use change). One type of change, the 'inverse storage effect' is characterized by an increase in the release of young water from the system in response to an increase in overall system storage. This effect can be seen in many hydrologic settings, and has important implications for the effect of altered hydroclimatic conditions on solute transport through a landscape. External variability, such as increased precipitation, can induce a decrease in mean transit time (and vice versa), but this effect is greatly enhanced if accompanied by an internal shift in flow pathways that increases the relative importance of younger water. These effects will be illustrated using data from field and experimental studies.

  11. Implications of agricultural land use change to ecosystem services in the Ganges delta.

    Science.gov (United States)

    Islam, G M Tarekul; Islam, A K M Saiful; Shopan, Ahsan Azhar; Rahman, Md Munsur; Lázár, Attila N; Mukhopadhyay, Anirban

    2015-09-15

    Ecosystems provide the basis for human civilization and natural capital for green economy and sustainable development. Ecosystem services may range from crops, fish, freshwater to those that are harder to see such as erosion regulation, carbon sequestration, and pest control. Land use changes have been identified as the main sources of coastal and marine pollution in Bangladesh. This paper explores the temporal variation of agricultural land use change and its implications with ecosystem services in the Ganges delta. With time agricultural lands have been decreased and wetlands have been increased at a very high rate mainly due to the growing popularity of saltwater shrimp farming. In a span of 28 years, the agricultural lands have been reduced by approximately 50%, while the wetlands have been increased by over 500%. A large portion (nearly 40%) of the study area is covered by the Sundarbans which remained almost constant which can be attributed to the strict regulatory intervention to preserve the Sundarbans. The settlement & others land use type has also been increased to nearly 5%. There is a gradual uptrend of shrimp and fish production in the study area. The findings suggest that there are significant linkages between agricultural land use change and ecosystem services in the Ganges delta in Bangladesh. The continuous decline of agricultural land (due to salinization) and an increase of wetland have been attributed to the conversion of agricultural land into shrimp farming in the study area. Such land use change requires significant capital, therefore, only investors and wealthier land owners can get the higher profit from the land conversion while the poor people is left with the environmental consequences that affect their long-term lives and livelihood. An environmental management plan is proposed for sustainable land use in the Ganges delta in Bangladesh. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. Transitions in Arctic ecosystems: Ecological implications of a changing hydrological regime

    Science.gov (United States)

    Wrona, Frederick J.; Johansson, Margareta; Culp, Joseph M.; Jenkins, Alan; Mârd, Johanna; Myers-Smith, Isla H.; Prowse, Terry D.; Vincent, Warwick F.; Wookey, Philip A.

    2016-03-01

    Numerous international scientific assessments and related articles have, during the last decade, described the observed and potential impacts of climate change as well as other related environmental stressors on Arctic ecosystems. There is increasing recognition that observed and projected changes in freshwater sources, fluxes, and storage will have profound implications for the physical, biogeochemical, biological, and ecological processes and properties of Arctic terrestrial and freshwater ecosystems. However, a significant level of uncertainty remains in relation to forecasting the impacts of an intensified hydrological regime and related cryospheric change on ecosystem structure and function. As the terrestrial and freshwater ecology component of the Arctic Freshwater Synthesis, we review these uncertainties and recommend enhanced coordinated circumpolar research and monitoring efforts to improve quantification and prediction of how an altered hydrological regime influences local, regional, and circumpolar-level responses in terrestrial and freshwater systems. Specifically, we evaluate (i) changes in ecosystem productivity; (ii) alterations in ecosystem-level biogeochemical cycling and chemical transport; (iii) altered landscapes, successional trajectories, and creation of new habitats; (iv) altered seasonality and phenological mismatches; and (v) gains or losses of species and associated trophic interactions. We emphasize the need for developing a process-based understanding of interecosystem interactions, along with improved predictive models. We recommend enhanced use of the catchment scale as an integrated unit of study, thereby more explicitly considering the physical, chemical, and ecological processes and fluxes across a full freshwater continuum in a geographic region and spatial range of hydroecological units (e.g., stream-pond-lake-river-near shore marine environments).

  13. Do the recommended standards for in vitro biopharmaceutic classification of drug permeability meet the "passive transport" criterion for biowaivers?

    Science.gov (United States)

    Žakelj, Simon; Berginc, Katja; Roškar, Robert; Kraljič, Bor; Kristl, Albin

    2013-01-01

    BCS based biowaivers are recognized by major regulatory agencies. An application for a biowaiver can be supported by or even based on "in vitro" measurements of drug permeability. However, guidelines limit the application of biowaivers to drug substances that are transported only by passive mechanisms. Regarding published permeability data as well as measurements obtained in our institution, one can rarely observe drug substances that conform to this very strict criterion. Therefore, we measured the apparent permeability coefficients of 13 drugs recommended by FDA's Guidance to be used as standards for "in vitro" permeability classification. The asymmetry of permeability data determined for both directions (mucosal-to-serosal and serosalto- mucosal) through the rat small intestine revealed significant active transport for four out of the nine high-permeability standards and for all four low-permeability standard drugs. As could be expected, this asymmetry was abolished at 4°C on rat intestine. The permeability of all nine high-permeability, but none of the low permeability standards, was also much lower when measured with intestinal tissue, Caco-2 cell monolayers or artificial membranes at 4°C compared to standard conditions (37°C). Additionally, concurrent testing of several standard drugs revealed that membrane transport can be affected by the use of internal permeability standards. The implications of the results are discussed regarding the regulatory aspects of biopharmaceutical classification, good practice in drug permeability evaluation and regarding the general relevance of transport proteins with broad specificity in drug absorption.

  14. Dangerous anthropogenic interference, dangerous climatic change, and harmful climatic change. Non-trivial distinctions with significant policy implications

    International Nuclear Information System (INIS)

    Harvey, L.D.D.

    2007-01-01

    climate sensitivity and three alternative pdfs for the harm temperature threshold. The allowable radiative forcing ratio depends on the probability of significant harm that is tolerated, and can be translated into allowable CO2 concentrations given some assumption concerning the future change in total non-CO2 GHG radiative forcing. If future non-CO2 GHG forcing is reduced to half of the present non-CO2 GHG forcing, then the allowable CO2 concentration is 290-430 ppmv for a 10% risk tolerance (depending on the chosen pdfs) and 300-500 ppmv for a 25% risk tolerance (assuming a pre-industrial CO2 concentration of 280 ppmv). For future non-CO2 GHG forcing frozen at the present value, and for a 10% risk threshold, the allowable CO2 concentration is 257-384 ppmv. The implications of these results are that (1) emissions of GHGs need to be reduced as quickly as possible, not in order to comply with the UNFCCC, but in order to minimize the extent and duration of non-compliance; (2) we do not have the luxury of trading off reductions in emissions of non-CO2 GHGs against smaller reductions in CO2 emissions, and (3) preparations should begin soon for the creation of negative CO2 emissions through the sequestration of biomass carbon

  15. Health risks of climate change: An assessment of uncertainties and its implications for adaptation policies

    Science.gov (United States)

    2012-01-01

    Background Projections of health risks of climate change are surrounded with uncertainties in knowledge. Understanding of these uncertainties will help the selection of appropriate adaptation policies. Methods We made an inventory of conceivable health impacts of climate change, explored the type and level of uncertainty for each impact, and discussed its implications for adaptation policy. A questionnaire-based expert elicitation was performed using an ordinal scoring scale. Experts were asked to indicate the level of precision with which health risks can be estimated, given the present state of knowledge. We assessed the individual scores, the expertise-weighted descriptive statistics, and the argumentation given for each score. Suggestions were made for how dealing with uncertainties could be taken into account in climate change adaptation policy strategies. Results The results showed that the direction of change could be indicated for most anticipated health effects. For several potential effects, too little knowledge exists to indicate whether any impact will occur, or whether the impact will be positive or negative. For several effects, rough ‘order-of-magnitude’ estimates were considered possible. Factors limiting health impact quantification include: lack of data, multi-causality, unknown impacts considering a high-quality health system, complex cause-effect relations leading to multi-directional impacts, possible changes of present-day response-relations, and difficulties in predicting local climate impacts. Participants considered heat-related mortality and non-endemic vector-borne diseases particularly relevant for climate change adaptation. Conclusions For possible climate related health impacts characterised by ignorance, adaptation policies that focus on enhancing the health system’s and society’s capability of dealing with possible future changes, uncertainties and surprises (e.g. through resilience, flexibility, and adaptive capacity) are

  16. Predicting chemically-induced skin reactions. Part II: QSAR models of skin permeability and the relationships between skin permeability and skin sensitization

    Science.gov (United States)

    Alves, Vinicius M.; Muratov, Eugene; Fourches, Denis; Strickland, Judy; Kleinstreuer, Nicole; Andrade, Carolina H.; Tropsha, Alexander

    2015-01-01

    Skin permeability is widely considered to be mechanistically implicated in chemically-induced skin sensitization. Although many chemicals have been identified as skin sensitizers, there have been very few reports analyzing the relationships between molecular structure and skin permeability of sensitizers and non-sensitizers. The goals of this study were to: (i) compile, curate, and integrate the largest publicly available dataset of chemicals studied for their skin permeability; (ii) develop and rigorously validate QSAR models to predict skin permeability; and (iii) explore the complex relationships between skin sensitization and skin permeability. Based on the largest publicly available dataset compiled in this study, we found no overall correlation between skin permeability and skin sensitization. In addition, cross-species correlation coefficient between human and rodent permeability data was found to be as low as R2=0.44. Human skin permeability models based on the random forest method have been developed and validated using OECD-compliant QSAR modeling workflow. Their external accuracy was high (Q2ext = 0.73 for 63% of external compounds inside the applicability domain). The extended analysis using both experimentally-measured and QSAR-imputed data still confirmed the absence of any overall concordance between skin permeability and skin sensitization. This observation suggests that chemical modifications that affect skin permeability should not be presumed a priori to modulate the sensitization potential of chemicals. The models reported herein as well as those developed in the companion paper on skin sensitization suggest that it may be possible to rationally design compounds with the desired high skin permeability but low sensitization potential. PMID:25560673

  17. Climate change and hailstorm damage: Empirical evidence and implications for agriculture and insurance

    International Nuclear Information System (INIS)

    Botzen, W.J.W.; Bouwer, L.M.; van den Bergh, J.C.J.M.

    2010-01-01

    There is much uncertainty about the effects of anthropogenic climate change on the frequency and severity of extreme weather events like hailstorms, and subsequent economic losses, while this is also relevant information for the design of climate policy. Few studies conducted indicate that a strong positive relation exists between hailstorm activity and hailstorm damage, as predicted by minimum temperatures using simple correlations. This relation suggests that hailstorm damage may increase in the future if global warming leads to further temperature increase. This study estimates a range of Tobit models of relations between normalized insured hailstorm damage to agriculture and several temperature and precipitation indicators for the Netherlands. Temporal dynamics are explicitly modelled. A distinction is made between damage costs for greenhouse horticulture and outdoor farming, which appear to be differently affected by variability in weather. 'Out of sample' forecast tests show that a combination of maximum temperatures and precipitation predicts hailstorm damage best. Extrapolations of the historical relations between hailstorm damage and weather indicators under climate change scenarios project a considerable increase in future hailstorm damage. Our estimates show that by 2050 annual hailstorm damage to outdoor farming could increase by between 25% and 50%, with considerably larger impacts on greenhouse horticulture in summer of more than 200%. The economic implications of more hailstorm damage for, and adaptation by, the agricultural and insurance sectors are discussed. (author)

  18. Morphological changes of placental syncytium and their implications for the pathogenesis of preeclampsia.

    Science.gov (United States)

    Roland, Cynthia S; Hu, Jian; Ren, Chun-E; Chen, Haibin; Li, Jinping; Varvoutis, Megan S; Leaphart, Lynn W; Byck, David B; Zhu, Xueqiong; Jiang, Shi-Wen

    2016-01-01

    Preeclampsia is a hypertensive disease that complicates many pregnancies, typically presenting with new-onset or worsening hypertension and proteinuria. It is well recognized that the placental syncytium plays a key role in the pathogenesis of preeclampsia. This review summarizes the findings pertaining to the structural alterations in the syncytium of preeclamptic placentas and analyzes their pathological implications for the development of preeclampsia. Changes in the trophoblastic lineage, including those in the proliferation of cytotrophoblasts, the formation of syncytiotrophoblast through cell fusion, cell apoptosis and syncytial deportation, are discussed in the context of preeclampsia. Extensive correlations are made between functional deficiencies and the alterations on the levels of gross anatomy, tissue histology, cellular events, ultrastructure, molecular pathways, and gene expression. Attention is given to the significance of dynamic changes in the syncytial turnover in preeclamptic placentas. Specifically, experimental evidences for the complex and obligatory role of syncytin-1 in cell fusion, cell-cycle regulation at the G1/S transition, and apoptosis through AIF-mediated pathway, are discussed in detail in the context of syncytium homeostasis. Finally, the recent observations on the aberrant fibrin deposition in the trophoblastic layer and the trophoblast immature phenotype in preeclamptic placentas and their potential pathogenic impact are also reviewed.

  19. Carbon dioxide emissions and climate change: policy implications for the cement industry

    International Nuclear Information System (INIS)

    Rehan, R.; Nehdi, M.

    2005-01-01

    There is growing awareness that the cement industry is a significant contributor to global carbon dioxide (CO 2 ) emissions. It is expected that this industry will come under increasing regulatory pressures to reduce its emissions and contribute more aggressively to mitigating global warming. It is important that the industry's stakeholders become more familiar with greenhouse gas (GHG) emission and associated global warming issues, along with emerging policies that may affect the future of the industry. This paper discusses climate change, the current and proposed actions for mitigating its effects, and the implications of such actions for the cement industry. International negotiations on climate change are summarized and mechanisms available under the Kyoto Protocol for reducing greenhouse gas emissions are explained. The paper examines some of the traditional and emerging policy instruments for greenhouse gas emissions and analyses their merits and drawbacks. The applicability, effectiveness and potential impact of these policy instruments for the global cement industry in general and the Canadian cement industry in particular are discussed with recommendations for possible courses of action

  20. THE SOCIAL-ECONOMIC IMPLICATIONS OF THE CLIMATE CHANGES IN ROMANIA

    Directory of Open Access Journals (Sweden)

    Gheorghe ZAMAN

    2005-12-01

    Full Text Available The social-economic implication of climatic changes in Romania are analysed under the following viewpoints: causes and effects; prevention and abatement; adjustment; institutional aspects of environmental management. The main reason of climatic changes is generated by the greenhouse effect (GE that determines the heating of the terrestrial surface, melt-down of icebergs, tornados, draughts and flooding more frequently and of increasing intensity. These extreme meteorological phenomena determine, over time, increasing human and material losses, which imposes measures with effects on short-, medium- and long-term for diminishing the greenhouse effect in accordance with the commitments and provisions of the Kyoto Protocol and the requirements for the sustainable development of the country. Proposals are made with respect to integrating environmental issues into economic and social development strategies, emphasising the need for increasing environment financing and attaching more importance to the Ministry of Environment which must couple its policy with the acquis communautaire and the EU programme for combating and preventing GE impact.

  1. Implication of volume changes in uranium oxides: A density functional study

    International Nuclear Information System (INIS)

    Szpunar, B.; Szpunar, J.A.; Milman, V.; Goldberg, A.

    2013-01-01

    In severe nuclear accident scenarios (in air environments and high temperatures) UO 2 fuel pellets oxidise to produce uranium oxides with higher oxygen content, e.g., U 4 O 9 or U 3 O 8 . As a first step in investigating the microstructural changes following UO 2 oxidation to hexagonal high temperature phase of U 3 O 8 , density functional quantum mechanical calculations of the structure, elastic properties and electronic structure of U 3 O 8 have been performed. The calculated properties of hexagonal phase of U 3 O 8 are compared to those of the orthorhombic pseudo-hexagonal phase which is stable at room temperature. The total energy technique based on the local density approximation plus Hubbard U as implemented in the CASTEP code is used to investigate changes in the lattice constants. The first-principles calculations predict a 35-42% increase in volume per uranium atom as a result of the transformation from UO 2 to U 3 O 8 , in agreement with experimental data. The implications of this prediction on the linear expansion and fragmentation of fuel are discussed. (authors)

  2. Screening for PTSD among detained adolescents: Implications of the changes in the DSM-5.

    Science.gov (United States)

    Modrowski, Crosby A; Bennett, Diana C; Chaplo, Shannon D; Kerig, Patricia K

    2017-01-01

    Screening for posttraumatic stress disorder (PTSD) is highly relevant for youth involved in the juvenile justice system given their high rates of trauma exposure and posttraumatic stress symptoms. However, to date, no studies have investigated the implications of the recent revisions to the Diagnostic and Statistical Manual for Mental Disorders (5th ed., DSM-5; American Psychiatric Association [APA], 2013) diagnostic criteria for PTSD for screening in this population. To this end, the present study compared PTSD screening rates using the Diagnostic and Statistical Manual of Mental Disorders (4th ed., text rev., DSM-IV-TR; APA, 2013) versus DSM-5 criteria in a group of detained adolescents. Participants included 209 youth (60 girls) aged 13-19 (M = 15.97, SD = 1.24). Youth completed measures of lifetime trauma exposure and past-month posttraumatic stress symptoms. Over 95% of youth in the sample reported exposure to at least 1 type of traumatic event. Approximately 19.60% of the sample screened positive for PTSD according to the DSM-5 compared to 17.70% according to the DSM-IV-TR. Girls were more likely than boys to screen positive for PTSD according to the DSM-IV-TR compared to the DSM-5. The main factors accounting for the differences in screening rates across the versions of PTSD criteria involved the removal of Criterion A2 from the DSM-5, the separation of avoidance symptoms (Criterion C) into their own cluster, the addition of a cluster involving negative alterations in cognitions and mood (Criterion D), and revisions to the cluster of arousal symptoms (Criterion E). Future research should continue to investigate gender differences in PTSD symptoms in youth and consider the implications of these diagnostic changes for the accurate diagnosis and referral to treatment of adolescents who demonstrate posttraumatic stress reactions. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  3. The changing health priorities of earthquake response and implications for preparedness: a scoping review.

    Science.gov (United States)

    Cartwright, C; Hall, M; Lee, A C K

    2017-09-01

    Earthquakes have substantial impacts on mortality in low- and middle-income countries (LMIC). The academic evidence base to support Disaster Risk Reduction activities in LMIC settings is, however, limited. We sought to address this gap by identifying the health and healthcare impacts of earthquakes in LMICs and to identify the implications of these findings for future earthquake preparedness. Scoping review. A scoping review was undertaken with systematic searches of indexed databases to identify relevant literature. Key study details, findings, recommendations or lessons learnt were extracted and analysed across individual earthquake events. Findings were categorised by time frame relative to earthquakes and linked to the disaster preparedness cycle, enabling a profile of health and healthcare impacts and implications for future preparedness to be established. Health services need to prepare for changing health priorities with a shift from initial treatment of earthquake-related injuries to more general health needs occurring within the first few weeks. Preparedness is required to address mental health and rehabilitation needs in the medium to longer term. Inequalities of the impact of earthquakes on health were noted in particular for women, children, the elderly, disabled and rural communities. The need to maintain access to essential services such as reproductive health and preventative health services were identified. Key preparedness actions include identification of appropriate leaders, planning and training of staff. Testing of plans was advocated within the literature with evidence that this is possible in LMIC settings. Whilst there are a range of health and healthcare impacts of earthquakes, common themes emerged in different settings and from different earthquake events. Preparedness of healthcare systems is essential and possible, in order to mitigate the adverse health impacts of earthquakes in LMIC settings. Preparedness is needed at the community

  4. Identification of two distinct fire regimes in Southern California: implications for economic impact and future change

    Science.gov (United States)

    Jin, Yufang; Goulden, Michael L.; Faivre, Nicolas; Veraverbeke, Sander; Sun, Fengpeng; Hall, Alex; Hand, Michael S.; Hook, Simon; Randerson, James T.

    2015-09-01

    The area burned by Southern California wildfires has increased in recent decades, with implications for human health, infrastructure, and ecosystem management. Meteorology and fuel structure are universally recognized controllers of wildfire, but their relative importance, and hence the efficacy of abatement and suppression efforts, remains controversial. Southern California’s wildfires can be partitioned by meteorology: fires typically occur either during Santa Ana winds (SA fires) in October through April, or warm and dry periods in June through September (non-SA fires). Previous work has not quantitatively distinguished between these fire regimes when assessing economic impacts or climate change influence. Here we separate five decades of fire perimeters into those coinciding with and without SA winds. The two fire types contributed almost equally to burned area, yet SA fires were responsible for 80% of cumulative 1990-2009 economic losses (3.1 Billion). The damage disparity was driven by fire characteristics: SA fires spread three times faster, occurred closer to urban areas, and burned into areas with greater housing values. Non-SA fires were comparatively more sensitive to age-dependent fuels, often occurred in higher elevation forests, lasted for extended periods, and accounted for 70% of total suppression costs. An improved distinction of fire type has implications for future projections and management. The area burned in non-SA fires is projected to increase 77% (±43%) by the mid-21st century with warmer and drier summers, and the SA area burned is projected to increase 64% (±76%), underscoring the need to evaluate the allocation and effectiveness of suppression investments.

  5. Memory, Plasticity and Sleep - A role for calcium permeable AMPA receptors?

    Directory of Open Access Journals (Sweden)

    Jason D Shepherd

    2012-04-01

    Full Text Available Experience shapes and molds the brain throughout life. These changes in neuronal circuits are produced by a myriad of molecular and cellular processes. Simplistically, circuits are modified through changes in neurotransmitter release or through neurotransmitter detection at synapses. The predominant neurotransmitter receptor in excitatory transmission, the AMPA-type glutamate receptor, is exquisitely sensitive to changes in experience and synaptic activity. These ion channels are usually impermeable to calcium, a property conferred by the GluA2 subunit. However, GluA2-lacking AMPARs are permeable to calcium and have recently been shown to play a unique role in synaptic function. In this review, I will describe new findings on the role of calcium permeable AMPARs (CP-AMPARs in experience-dependent and synaptic plasticity. These studies suggest that CP-AMPARs play a prominent role in maintaining circuits in a labile state where further plasticity can occur, thus promoting metaplasticity. Moreover, the abnormal expression of CP-AMPARs has been implicated in drug addiction and memory disorders and thus may be a novel therapeutic target.

  6. Can biofuels be a solution to climate change? The implications of land use change-related emissions for policy

    Science.gov (United States)

    Khanna, Madhu; Crago, Christine L.; Black, Mairi

    2011-01-01

    Biofuels have gained increasing attention as an alternative to fossil fuels for several reasons, one of which is their potential to reduce the greenhouse gas (GHG) emissions from the transportation sector. Recent studies have questioned the validity of claims about the potential of biofuels to reduce GHG emissions relative to the liquid fossil fuels they are replacing when emissions owing to direct (DLUC) and indirect land use changes (ILUC) that accompany biofuels are included in the life cycle GHG intensity of biofuels. Studies estimate that the GHG emissions released from ILUC could more than offset the direct GHG savings by producing biofuels and replacing liquid fossil fuels and create a ‘carbon debt’ with a long payback period. The estimates of this payback period, however, vary widely across biofuels from different feedstocks and even for a single biofuel across different modelling assumptions. In the case of corn ethanol, this payback period is found to range from 15 to 200 years. We discuss the challenges in estimating the ILUC effect of a biofuel and differences across biofuels, and its sensitivity to the assumptions and policy scenarios considered by different economic models. We also discuss the implications of ILUC for designing policies that promote biofuels and seek to reduce GHG emissions. In a first-best setting, a global carbon tax is needed to set both DLUC and ILUC emissions to their optimal levels. However, it is unclear whether unilateral GHG mitigation policies, even if they penalize the ILUC-related emissions, would increase social welfare and lead to optimal emission levels. In the absence of a global carbon tax, incentivizing sustainable land use practices through certification standards, government regulations and market-based pressures may be a viable option for reducing ILUC. PMID:22482030

  7. A non-erasable magnetic memory based on the magnetic permeability

    International Nuclear Information System (INIS)

    Petrie, J.R.; Wieland, K.A.; Burke, R.A.; Newburgh, G.A.; Burnette, J.E.; Fischer, G.A.; Edelstein, A.S.

    2014-01-01

    A non-erasable memory based on using differences in the magnetic permeability is demonstrated. The method can potentially store information indefinitely. Initially the high permeability bits were 10–50 μm wide lines of sputtered permalloy (Ni 81 Fe 19 ) on a glass substrate. In a second writing technique a continuous film of amorphous, high permeability ferromagnetic Metglas (Fe 78 Si 13 B 9 ) was sputtered onto a similar glass substrate. Low permeability, crystalline 50 μm wide lines were then written in the film by laser heating. Both types of written media were read by applying an external probe field that is locally modified by the permeability of each bit. The modifications in the probe field were read by a nearby set of 10 micron wide magnetic tunnel junctions with a signal-to-noise ratio of up to 45 dB. This large response to changes in bit permeability is not altered after the media has been exposed to a 6400 Oe field. While being immediately applicable for data archiving and secure information storage, higher densities are possible with smaller read and write heads. - Highlights: • We demonstrate a non-erasable memory based on changes in the magnetic permeability. • Large change in permeability occur when Metglas changes from amorphous to crystalline. • Micron size regions of Metglas can be crystallized using a laser. • Permeability changes read by observing deviations of a probe field with an MTJ

  8. Long-term bioventing performance in low-permeability soils

    International Nuclear Information System (INIS)

    Phelps, M.B.; Stanin, F.T.; Downey, D.C.

    1995-01-01

    Short-term and long-term bioventing treatability testing has shown that in situ air injection and extraction is a practical method for sustaining increased oxygen levels and enhancing aerobic biodegradation of petroleum hydrocarbons in low-permeability soils. At several test sites, initial physical parameter analysis of soils and air permeability tests indicated that impacted soils (fine sandy silts and clays) had low air permeabilities. Measurements of depleted soil-gas oxygen levels and increased soil-gas carbon dioxide levels indicated that the natural process of aerobic biodegradation of petroleum hydrocarbons was oxygen-limited. Initial treatability testing consisted of air permeability tests to measure the permeability of the soils to air and in situ respiration tests to measure the rates at which native microorganisms could biodegrade the contaminants when provided with sufficient oxygen. During the long-term treatment period, active air injection or extraction systems were operated for 1 year or longer. Soil gas was periodically monitored within the treatment zone to evaluate the success of the bioventing systems in increasing soil-gas oxygen levels in the low-permeability soils. Follow-up respiration tests and soil and soil-gas sampling were conducted to evaluate changes in respiration rates and contaminant concentrations with time

  9. The permeability and consolidation of deep-sea sediments

    International Nuclear Information System (INIS)

    Schultheiss, P.J.; Gunn, D.E.

    1985-01-01

    This report presents permeability and consolidation data for a wide range of sediment types. Permeability is one of the two parameters which are needed to directly quantify pore water advection in deep sea sediments and which are being investigated in high-level radioactive waste study areas. While it is desirable that these parameters should be measured in situ it is argued that values of permeability can be measured sufficiently accurately in the laboratory from core samples. Consequently, an apparatus has been developed which enables sediment permeability to be measured at decreasing void ratios during a back-pressured consolidation test. Data presented in this report from over 60 samples have established the major differences in permeability between various sediment types and how permeability changes as a function of burial depth and void ratio. Samples from two study areas in the North Atlantic Ocean, King's Trough Flank (KTF) and Great Meteor East (GME), have been compared with samples of Red Clay (RC) obtained from the NW Pacific Ocean. Results are presented and discussed. (author)

  10. Highly permeable, cement-bounded backfilling mortars for SMA repositories

    International Nuclear Information System (INIS)

    Jacobs, F.; Mayer, G.; Wittmann, F.H.

    1994-03-01

    In low- and intermediate-level waste repositories, gas is produced due e.g. to corrosion. This gas must be able to escape from the repository in order to prevent damage to the repository structure. A cement-based backfill should take over this function. For this purpose, the composition of cement-based materials was varied to study their influence on porosity and permeability. In parallel to this study the behaviour of fresh concrete, the liberation of the heat of hydration and the hardened concrete properties were investigated. To characterize the permeability of cement-based materials the following parameters are important: 1) composition of the material (pore fabric), 2) storage conditions (degree of saturation), 3) degree of hydration (age), 4) measuring fluid. A change in the composition of cement-based materials can vary the permeability by ten orders of magnitude. It is shown that, by using dense aggregates, the transport of the fluid takes place through the matrix and along the aggregate/matrix interface. By using porous aggregates the permeability can be increased by two orders of magnitude. In the case of a dense matrix, porous aggregates do not alter the permeability. Increasing the matrix content or interface content increases permeability. Hence light weight mortars are an obvious choice. Like-grained mixes showed higher permeabilities in combination with better mechanical properties but, in comparison to normal mixes, they showed worse flow properties. With the composition cement-: water-: aggregate content 1:0.4:5.33 the likegrained mix with aggregates ranging from 2 to 3 mm proved to be a suitable material. With a low compaction after 28 days this mix reaches a permeability of 4.10 -12 m 2 and an uniaxial cylinder compressive strength of 16 N/mm 2 . (author) 58 figs., 23 tabs., refs

  11. Climate change implications in the northern coastal temperate rainforest of North America

    Science.gov (United States)

    Shanley, Colin S.; Pyare, Sanjay; Goldstein, Michael I.; Alaback, Paul B.; Albert, David M.; Beier, Colin M.; Brinkman, Todd J.; Edwards, Rick T.; Hood, Eran; MacKinnon, Andy; McPhee, Megan V.; Patterson, Trista; Suring, Lowell H.; Tallmon, David; Wipfli, Mark S.

    2015-01-01

    We synthesized an expert review of climate change implications for hydroecological and terrestrial ecological systems in the northern coastal temperate rainforest of North America. Our synthesis is based on an analysis of projected temperature, precipitation, and snowfall stratified by eight biogeoclimatic provinces and three vegetation zones. Five IPCC CMIP5 global climate models (GCMs) and two representative concentration pathways (RCPs) are the basis for projections of mean annual temperature increasing from a current average (1961–1990) of 3.2 °C to 4.9–6.9 °C (5 GCM range; RCP4.5 scenario) or 6.4–8.7 °C (RCP8.5), mean annual precipitation increasing from 3130 mm to 3210–3400 mm (3–9 % increase) or 3320–3690 mm (6–18 % increase), and total precipitation as snow decreasing from 1200 mm to 940–720 mm (22–40 % decrease) or 720–500 mm (40–58 % decrease) by the 2080s (2071–2100; 30-year normal period). These projected changes are anticipated to result in a cascade of ecosystem-level effects including: increased frequency of flooding and rain-on-snow events; an elevated snowline and reduced snowpack; changes in the timing and magnitude of stream flow, freshwater thermal regimes, and riverine nutrient exports; shrinking alpine habitats; altitudinal and latitudinal expansion of lowland and subalpine forest types; shifts in suitable habitat boundaries for vegetation and wildlife communities; adverse effects on species with rare ecological niches or limited dispersibility; and shifts in anadromous salmon distribution and productivity. Our collaborative synthesis of potential impacts highlights the coupling of social and ecological systems that characterize the region as well as a number of major information gaps to help guide assessments of future conditions and adaptive capacity.

  12. Weather effects on avian breeding performance and implications of climate change

    Science.gov (United States)

    Skagen, Susan K.; Yackel Adams, Amy A.

    2012-01-01

    The influence of recent climate change on the world’s biota has manifested broadly, resulting in latitudinal range shifts, advancing dates of arrival of migrants and onset of breeding, and altered community relationships. Climate change elevates conservation concerns worldwide because it will likely exacerbate a broad range of identified threats to animal populations. In the past few decades, grassland birds have declined faster than other North American avifauna, largely due to habitat threats such as the intensification of agriculture. We examine the effects of local climatic variations on the breeding performance of a bird endemic to the shortgrass prairie, the Lark Bunting (Calamospiza melanocorys) and discuss the implications of our findings relative to future climate predictions. Clutch size, nest survival, and productivity all positively covaried with seasonal precipitation, yet relatively intense daily precipitation events temporarily depressed daily survival of nests. Nest survival was positively related to average temperatures during the breeding season. Declining summer precipitation may reduce the likelihood that Lark Buntings can maintain stable breeding populations in eastern Colorado although average temperature increases of up to 38C (within the range of this study) may ameliorate declines in survival expected with drier conditions. Historic climate variability in the Great Plains selects for a degree of vagility and opportunism rather than strong site fidelity and specific adaptation to local environments. These traits may lead to northerly shifts in distribution if climatic and habitat conditions become less favorable in the drying southern regions of the Great Plains. Distributional shifts in Lark Buntings could be constrained by future changes in land use, agricultural practices, or vegetative communities that result in further loss of shortgrass prairie habitats.

  13. EXPOSURE TO INTERMITTENT AIR POLLUTION AND CHANGES IN SEMEN QUALITY: EVIDENCE FOR AN ASSOCIATION AND IMPLICATIONS FOR REPRODUCTIVE RISK ASSESSMENT

    Science.gov (United States)

    Exposure to Intermittent Air Pollution and Changes in Semen Quality:Evidence for an Association and Implications for Reproductive Risk Assessment. S. D. Perreault1, S.G. Selevan2, J. Rubes3, D. Zudova3, and D.P. Evenson4 1US EPA, ORD/NHEERL, Research Triangle Pa...

  14. Transverse Chemotactic Migration of Bacteria from High to Low Permeability Regions in a Dual Permeability Porous Microfluidic Device

    Science.gov (United States)

    Singh, R.; Olson, M. S.

    2011-12-01

    Low permeability regions sandwiched between high permeability regions such as clay lenses are difficult to treat using conventional treatment methods. Trace concentrations of contaminants such as non-aqueous phase liquids (NAPLs) remain trapped in these regions and over the time diffuse out into surrounding water thereby acting as a long term source of groundwater contamination. Bacterial chemotaxis (directed migration toward a contaminant source), may be helpful in enhancing bioremediation of such contaminated sites. This study is focused on simulating a two-dimensional dual-permeability groundwater contamination scenario using microfluidic devices and evaluating transverse chemotactic migration of bacteria from high to low permeability regions. A novel bi-layer polydimethylsiloxane (PDMS) microfluidic device was fabricated using photolithography and soft lithography techniques to simulate contamination of a dual- permeability region due to leakage from an underground storage tank into a low permeability region. This device consists of a porous channel through which a bacterial suspension (Escherchia Coli HCB33) is flown and another channel for injecting contaminant/chemo-attractant (DL-aspertic acid) into the porous channel. The pore arrangement in the porous channel contains a 2-D low permeability region surrounded by high permeability regions on both sides. Experiments were performed under chemotactic and non-chemotactic (replacing attractant with buffer solution in the non porous channel) conditions. Images were captured in transverse pore throats at cross-sections 4.9, 9.8, and 19.6 mm downstream from the attractant injection point and bacteria were enumerated in the middle of each pore throat. Bacterial chemotaxis was quantified in terms of the change in relative bacterial counts in each pore throat at cross-sections 9.8 and 19.6 mm with respect to counts at the cross-section at 4.9 mm. Under non-chemotactic conditions, relative bacterial count was observed

  15. Implication of changing loading conditions on structural health monitoring utilising guided waves

    Science.gov (United States)

    Mohabuth, Munawwar; Kotousov, Andrei; Ng, Ching-Tai; Rose, L. R. Francis

    2018-02-01

    Structural health monitoring systems based on guided waves typically utilise a network of embedded or permanently attached sensors, allowing for the continuous detection of damage remote from a sensor location. The presence of damage is often diagnosed by analysing the residual signals from the structure after subtracting damage-free reference data. However, variations in environmental and operational conditions such as temperature, humidity, applied or thermally-induced stresses affect the measured residuals. A previously developed acoustoelastic formulation is here extended and employed as the basis for a simplified analytical model to estimate the effect of applied or thermally-induced stresses on the propagation characteristics of the fundamental Lamb wave modes. It is noted that there are special combinations of frequency, biaxial stress ratio and direction of wave propagation for which there is no change in the phase velocity of the fundamental anti-symmetric mode. The implication of these results in devising effective strategies to mitigate the effect of stress induced variations in guided-wave damage diagnostics is briefly discussed.

  16. Air pollution management and control in Latin America and the Caribbean: implications for climate change.

    Science.gov (United States)

    Riojas-Rodríguez, Horacio; da Silva, Agnes Soares; Texcalac-Sangrador, José Luis; Moreno-Banda, Grea Litai

    2016-09-01

    To assess the status of the legal framework for air quality control in all countries of Latin America and Caribbean (LAC); to determine the current distribution of air monitoring stations and mean levels of air pollutants in all capital and large cities (more than 100 000 inhabitants); and to discuss the implications for climate change and public policymaking. From January 2015-February 2016, searches were conducted of online databases for legislation, regulations, policies, and air pollution programs, as well as for the distribution of monitoring stations and the mean annual levels of air pollution in all LAC countries. Only 117 cities distributed among 17 of 33 LAC countries had official information on ground level air pollutants, covering approximately 146 million inhabitants. The annual mean of inhalable particles concentration in most of the cities were over the World Health Organization Air Quality Guidelines; notably, only Bolivia, Peru, and Guatemala have actually adopted the guidelines. Most of the cities did not have information on particulate matter of 2.5 microns or less, and only a few measured black carbon. The air quality regulatory framework should be updated to reflect current knowledge on health effects. Monitoring and control of ground level pollutants should be extended and strengthened to increase awareness and protect public health. Using the co-benefits of air pollution control for health and climate as a framework for policy and decision-making in LAC is recommended.

  17. The Southern Oscillation in a coupled GCM: Implications for climate sensitivity and climate change

    International Nuclear Information System (INIS)

    Meehl, G.A.

    1990-01-01

    Results are presented from a global coupled ocean-atmosphere general circulation climate model developed at the National Center for Atmospheric Research. The atmospheric part of the coupled model is a global spectral (R15, 4.5 degree latitude by 7.5 degree longitude, 9 layers in the vertical) general circulation model. The ocean is coarse-grid (5 degree latitude by 5 degree longitude, 4 layers in the vertical) global general circulation model. The coupled model includes a simple thermodynamic sea-ice model. Due mainly to inherent limitations in the ocean model, the coupled model simulates sea surface temperatures that are too low in the tropics and too high in the extratropics in the mean. In spite of these limitations, the coupled model simulates active interannual variability of the global climate system involving signals in the tropical Pacific that resemble, in some respects, the observed Southern Oscillation. These signals in the tropics are associated with teleconnections to the extratropics of both hemispheres. The implications of this model-simulated interannual variability of the coupled system relating to climate sensitivity and climate change due to an increase of atmospheric carbon dioxide are discussed

  18. The Southern Oscillation in a coupled GCM: Implications for climate sensitivity and climate change

    International Nuclear Information System (INIS)

    Meehl, G.A.

    1991-01-01

    Results are presented from a global coupled ocean-atmosphere general circulation climate model developed at the National Center for Atmospheric Research. The atmospheric part of the coupled model is a global spectral (R15, 4.5 degree latitude by 7.5 degree longitude, 9 layers in the vertical) general circulation model. The ocean is coarse-grid (5 degree latitude by 5 degree longitude, 4 layers in the vertical) global general circulation model. The coupled model includes a simple thermodynamic sea-ice model. Due mainly to inherent limitations in the ocean model, the coupled model simulates sea surface temperatures that are too low in the tropics and too high in the extratropics in the mean. In spite of these limitations, the coupled model simulates active interannual variability of the global climate system involving signals in the tropical Pacific that resemble, in some respects, the observed Southern Oscillation. These signals in the tropics are associated with teleconnections to the extratropics of both hemispheres. The implications of this model-simulated interannual variability of the coupled system relating to climate sensitivity and climate change due to an increase of atmospheric carbon dioxide are discussed. 25 refs.; 9 figs

  19. Practicing Multicultural Education through Religiously Affiliated Schools and Its Implications for Social Change

    Directory of Open Access Journals (Sweden)

    Miftahur Rohman

    2017-06-01

    Full Text Available Having varied ethnics, cultures, religions, or faiths, Indonesia is considered a multicultural nation in today’s world. This equity can be dangerous; but also can be advantageous if myriad interests of citizens are able to be nurtured through education, including religious schools. The research was conducted to explore multicultural practices in the State-owned Islamic High School (MAN 3 and the Catholic High School (SMA Stella Duce 2 in Yogyakarta Indonesia. Data was gathered via qualitative method by means of comparative study, aiming at seeking similarities and differences on promoting multicultural education values. Findings show similarities of teachers’ attitudes and characteristics as facilitator, accommodator, or assimilator whereas the differences include their leadership role in intrareligious dialog at MAN 3 and dialog leaders at SMA Stella Duce 2. Other issues include diverse understandings of religion and its perceived violence. The research formulates two categories of teacher as being multicultural-intrareligious pluralist and multicultural-intrareligious humanist. It also discusses implications on social change as a result of cultural interchange at those schools.

  20. Review of economic and energy sector implications of adopting global climate change policies

    Energy Technology Data Exchange (ETDEWEB)

    Novak, M.H.

    1997-12-31

    This paper summarizes a number of studies examining potential economic impacts of global climate change policies. Implications for the United States as a whole, the U.S. energy sector, the U.S. economy, businesses and consumers, and world economies are considered. Impact assessments are performed of U.S. carbon emissions, carbon taxes, and carbon restrictions by comparing estimates from various organizations. The following conclusions were made from the economic studies: (1) the economic cost of carbon abatement is expensive; (2) the cost of unilateral action is very expensive with little quantifiable evidence that global emissions are reduced; (3) multilateral actions of developed countries are also very expensive, but there is quantifiable evidence of global emissions reductions; and (4) global actions have only been theoretically addressed. Paralleling these findings, the energy analyses show that the U.S. is technologically unprepared to give up fossil fuels. As a result: (1) carbon is not stabilized without a high tax, (2) stabilization of carbon is elusive, (3) technology is the only long-term answer, and (4) targeted programs may be appropriate to force technology development. 8 tabs.

  1. Air pollution management and control in Latin America and the Caribbean: implications for climate change

    Directory of Open Access Journals (Sweden)

    Horacio Riojas-Rodríguez

    Full Text Available ABSTRACT Objective To assess the status of the legal framework for air quality control in all countries of Latin America and Caribbean (LAC; to determine the current distribution of air monitoring stations and mean levels of air pollutants in all capital and large cities (more than 100 000 inhabitants; and to discuss the implications for climate change and public policymaking. Methods From January 2015–February 2016, searches were conducted of online databases for legislation, regulations, policies, and air pollution programs, as well as for the distribution of monitoring stations and the mean annual levels of air pollution in all LAC countries. Results Only 117 cities distributed among 17 of 33 LAC countries had official information on ground level air pollutants, covering approximately 146 million inhabitants. The annual mean of inhalable particles concentration in most of the cities were over the World Health Organization Air Quality Guidelines; notably, only Bolivia, Peru, and Guatemala have actually adopted the guidelines. Most of the cities did not have information on particulate matter of 2.5 microns or less, and only a few measured black carbon. Conclusions The air quality regulatory framework should be updated to reflect current knowledge on health effects. Monitoring and control of ground level pollutants should be extended and strengthened to increase awareness and protect public health. Using the co-benefits of air pollution control for health and climate as a framework for policy and decision-making in LAC is recommended.

  2. Health Implications of Climate Change: a Review of the Literature About the Perception of the Public and Health Professionals.

    Science.gov (United States)

    Hathaway, Julia; Maibach, Edward W

    2018-03-01

    Through a systematic search of English language peer-reviewed studies, we assess how health professionals and the public, worldwide, perceive the health implications of climate change. Among health professionals, perception that climate change is harming health appears to be high, although self-assessed knowledge is low, and perceived need to learn more is high. Among the public, few North Americans can list any health impacts of climate change, or who is at risk, but appear to view climate change as harmful to health. Among vulnerable publics in Asia and Africa, awareness of increasing health harms due to specific changing climatic conditions is high. Americans across the political and climate change opinion spectra appear receptive to information about the health aspects of climate change, although findings are mixed. Health professionals feel the need to learn more, and the public appears open to learning more, about the health consequences of climate change.

  3. Endothelial glycocalyx dysfunction in disease: albuminuria and increased microvascular permeability.

    Science.gov (United States)

    Salmon, Andrew H J; Satchell, Simon C

    2012-03-01

    Appreciation of the glomerular microcirculation as a specialized microcirculatory bed, rather than as an entirely separate entity, affords important insights into both glomerular and systemic microvascular pathophysiology. In this review we compare regulation of permeability in systemic and glomerular microcirculations, focusing particularly on the role of the endothelial glycocalyx, and consider the implications for disease processes. The luminal surface of vascular endothelium throughout the body is covered with endothelial glycocalyx, comprising surface-anchored proteoglycans, supplemented with adsorbed soluble proteoglycans, glycosaminoglycans and plasma constituents. In both continuous and fenestrated microvessels, this endothelial glycocalyx provides resistance to the transcapillary escape of water and macromolecules, acting as an integral component of the multilayered barrier provided by the walls of these microvessels (ie acting in concert with clefts or fenestrae across endothelial cell layers, basement membranes and pericytes). Dysfunction of any of these capillary wall components, including the endothelial glycocalyx, can disrupt normal microvascular permeability. Because of its ubiquitous nature, damage to the endothelial glycocalyx alters the permeability of multiple capillary beds: in the glomerulus this is clinically apparent as albuminuria. Generalized damage to the endothelial glycocalyx can therefore manifest as both albuminuria and increased systemic microvascular permeability. This triad of altered endothelial glycocalyx, albuminuria and increased systemic microvascular permeability occurs in a number of important diseases, such as diabetes, with accumulating evidence for a similar phenomenon in ischaemia-reperfusion injury and infectious disease. The detection of albuminuria therefore has implications for the function of the microcirculation as a whole. The importance of the endothelial glycocalyx for other aspects of vascular function

  4. Implications of global climate change for the assessment and management of human health risks of chemicals in the natural environment.

    Science.gov (United States)

    Balbus, John M; Boxall, Alistair B A; Fenske, Richard A; McKone, Thomas E; Zeise, Lauren

    2013-01-01

    Global climate change (GCC) is likely to alter the degree of human exposure to pollutants and the response of human populations to these exposures, meaning that risks of pollutants could change in the future. The present study, therefore, explores how GCC might affect the different steps in the pathway from a chemical source in the environment through to impacts on human health and evaluates the implications for existing risk-assessment and management practices. In certain parts of the world, GCC is predicted to increase the level of exposure of many environmental pollutants due to direct and indirect effects on the use patterns and transport and fate of chemicals. Changes in human behavior will also affect how humans come into contact with contaminated air, water, and food. Dietary changes, psychosocial stress, and coexposure to stressors such as high temperatures are likely to increase the vulnerability of humans to chemicals. These changes are likely to have significant implications for current practices for chemical assessment. Assumptions used in current exposure-assessment models may no longer apply, and existing monitoring methods may not be robust enough to detect adverse episodic changes in exposures. Organizations responsible for the assessment and management of health risks of chemicals therefore need to be more proactive and consider the implications of GCC for their procedures and processes. Copyright © 2012 SETAC.

  5. Quantifying Evaporation in a Permeable Pavement System

    Science.gov (United States)

    Studies quantifying evaporation from permeable pavement systems are limited to a few laboratory studies and one field application. This research quantifies evaporation for a larger-scale field application by measuring the water balance from lined permeable pavement sections. Th...

  6. Permeable Pavement Research - Edison, New Jersey

    Science.gov (United States)

    This presentation provides the background and summary of results collected at the permeable pavement parking lot monitored at the EPA facility in Edison, NJ. This parking lot is surfaced with permeable interlocking concrete pavers (PICP), pervious concrete, and porous asphalt. ...

  7. Use of Interface Treatment to Reduce Emissions from Residuals in Lower Permeability Zones to Groundwater flowing Through More Permeable Zones (Invited)

    Science.gov (United States)

    Johnson, P.; Cavanagh, B.; Clifton, L.; Daniels, E.; Dahlen, P.

    2013-12-01

    Many soil and groundwater remediation technologies rely on fluid flow for contaminant extraction or reactant delivery (e.g., soil vapor extraction, pump and treat, in situ chemical oxidation, air sparging, enhanced bioremediation). Given that most unconsolidated and consolidated settings have permeability contrasts, the outcome is often preferential treatment of more permeable zones and ineffective treatment of the lower permeability zones. When this happens, post-treatment contaminant emissions from low permeability zone residuals can cause unacceptable long-term impacts to groundwater in the transmissive zones. As complete remediation of the impacted lower permeability zones may not be practicable with conventional technologies, one might explore options that lead to reduction of the contaminant emissions to acceptable levels, rather than full remediation of the lower permeability layers. This could be accomplished either by creating a sustained emission reaction/attenuation zone at the high-low permeability interface, or by creating a clean soil zone extending sufficiently far into the lower permeability layer to cause the necessary reduction in contaminant concentration gradient and diffusive emission. These options are explored in proof-of-concept laboratory-scale physical model experiments. The physical models are prepared with two layers of contrasting permeability and either dissolved matrix storage or nonaqueous phase liquid (NAPL) in the lower permeability layer. A dissolved oxidant is then delivered to the interface via flow across the higher permeability layer and changes in contaminant emissions from the low permeability zone are monitored before, during, and after oxidant delivery. The use of three oxidants (dissolved oxygen, hydrogen peroxide and sodium persulfate) for treatment of emissions from petroleum hydrocarbon residuals is examined.

  8. Socio-economic implications of structural changes in plantations in Asian countries.

    OpenAIRE

    Sircar KN; Navamukundan, A; Sajhau JP; Sukarja R

    1985-01-01

    ILO pub. Working paper on the economic implications and social implications of restructuring in plantations in India, Indonesia, Malaysia and Sri Lanka - covers agricultural production, employment, working conditions of plantation workers, wages, management, and public ownership or private ownership of tea, coffee, rubber, etc. Plantations; comments on labour legislation. Bibliography, statistical tables.

  9. Quantifying porosity, compressibility and permeability in Shale

    DEFF Research Database (Denmark)

    Mbia, Ernest Ncha; Fabricius, Ida Lykke; Frykman, Peter

    strain data. We found that Kozeny's modelled permeability fall in the same order of magnitude with measured permeability for shale rich in kaolinite but overestimates permeability by two to three orders of magnitudes for shale with high content of smectite. The empirical Yang and Aplin model gives good...... permeability estimate comparable to the measured one for shale rich in smectite. This is probably because Yang and Aplin model was calibrated in London clay which is rich in smectite....

  10. Viscous fingering with permeability heterogeneity

    International Nuclear Information System (INIS)

    Tan, C.; Homsy, G.M.

    1992-01-01

    Viscous fingering in miscible displacements in the presence of permeability heterogeneities is studied using two-dimensional simulations. The heterogeneities are modeled as stationary random functions of space with finite correlation scale. Both the variance and scale of the heterogeneities are varied over modest ranges. It is found that the fingered zone grows linearly in time in a fashion analogous to that found in homogeneous media by Tan and Homsy [Phys. Fluids 31, 1330 (1988)], indicating a close coupling between viscous fingering on the one hand and flow through preferentially more permeable paths on the other. The growth rate of the mixing zone increases monotonically with the variance of the heterogeneity, as expected, but shows a maximum as the correlation scale is varied. The latter is explained as a ''resonance'' between the natural scale of fingers in homogeneous media and the correlation scale

  11. Soil gas measurements at high permeabilities and below foundation depth

    International Nuclear Information System (INIS)

    Johner, H.U; Surbeck, H.

    2000-01-01

    We started a project of soil gas measurements beneath houses. Since the foundations of houses often lie deeper than 0.5 to 1 m - the depth where soil gas measurements are often made - the first approach was to apply the method developed previously to deeper soil layers. The radon availability index (RAI), which was defined empirically, proved to be a reliable indicator for radon problems in nearby houses. The extreme values of permeability, non-Darcy flow and scale dependence of permeability stimulated the development of a multi-probe method. A hydrological model was applied to model the soil gas transport. The soil gas measurements below foundation depth provided a wealth of new information. A good classification of soil properties could be achieved. If soil gas measurements are to be made, the low permeability layer has to be traversed. A minimum depth of 1 .5 m is suggested, profiles to below the foundation depth are preferable. There are also implications for mitigation works. A sub-slab suction system should reach the permeable layer to function well. This also holds for radon wells. If a house is located on a slope, it is most convenient to install the sub-slab suction system on the hillside, as the foundation reaches the deepest levels there

  12. Climate change in the sea: the implications of increasing the carbon dioxide inputs to the surface ocean

    Energy Technology Data Exchange (ETDEWEB)

    Pfister, Cathy [University of Chicago

    2012-12-23

    The oceans are estimated to be absorbing one-third of the fossil fuel carbon released into the atmosphere, a process that is expected to change ocean carbon chemistry. I will present data from the Washington coast showing ocean pH declines and changes to the shell chemistry of bivalves. I will discuss implications of carbon cycle changes for marine species, including insights from a coastal area where I have worked for more than 24 years. I will summarize what we know to date about this process of “ocean acidification”.

  13. Putting the brakes on reproduction: Implications for conservation, global climate change and biomedicine.

    Science.gov (United States)

    Wingfield, John C; Perfito, Nicole; Calisi, Rebecca; Bentley, George; Ubuka, T; Mukai, M; O'Brien, Sara; Tsutsui, K

    2016-02-01

    Seasonal breeding is widespread in vertebrates and involves sequential development of the gonads, onset of breeding activities (e.g. cycling in females) and then termination resulting in regression of the reproductive system. Whereas males generally show complete spermatogenesis prior to and after onset of breeding, females of many vertebrate species show only partial ovarian development and may delay onset of cycling (e.g. estrous), yolk deposition or germinal vesicle breakdown until conditions conducive for ovulation and onset of breeding are favorable. Regulation of this "brake" on the onset of breeding remains relatively unknown, but could have profound implications for conservation efforts and for "mismatches" of breeding in relation to global climate change. Using avian models it is proposed that a brain peptide, gonadotropin-inhibitory hormone (GnIH), may be the brake to prevent onset of breeding in females. Evidence to date suggests that although GnIH may be involved in the regulation of gonadal development and regression, it plays more regulatory roles in the process of final ovarian development leading to ovulation, transitions from sexual to parental behavior and suppression of reproductive function by environmental stress. Accumulating experimental evidence strongly suggests that GnIH inhibits actions of gonadotropin-releasing hormones on behavior (central effects), gonadotropin secretion (central and hypophysiotropic effects), and has direct actions in the gonad to inhibit steroidogenesis. Thus, actual onset of breeding activities leading to ovulation may involve environmental cues releasing an inhibition (brake) on the hypothalamo-pituitary-gonad axis. Copyright © 2015 Elsevier Inc. All rights reserved.

  14. The effects of heavy metal ions on the chlorophyll content and cell membrane permeability of charophytes

    International Nuclear Information System (INIS)

    Fu Hualong; Chen Hao; Dong Bin; Qing Renwei

    2001-01-01

    The authors studied the effects of several heavy metal ions in different concentrations (Cd 2+ , Hg 2+ , Pb 2+ , Cr 6+ ) on the chlorophyll content and cell membrane permeability of Chara vulgaris L. It was discovered that the effects of heavy metal ions on the chlorophyll content and cell membrane permeability of Chara vulgaris L. changed with their different concentration. The trend was that the chlorophyll content and cell membrane permeability were decreased with the increase of the heavy metal ions. The degree of chlorophyll content affected was Cr 6+ , Cd 2+ , Hg 2+ , Pb 2+ , and that of cell membrane permeability affected was Cd 2+ , Cr 6+ , Hg 2+ , Pb 2+

  15. Changes in East Asian Food Consumption: Some Implications for Australian Irrigated Agriculture

    OpenAIRE

    Philip Taylor; Christopher Findlay

    1996-01-01

    This paper reviews the implications of economic growth for food consumption in Asia, the East Asian supply responses and the determinants of Australian competitiveness in meeting Asian demand from production in Australia. Our special interests are to draw out some implications for Australia’s irrigated agriculture and for the organisation of the export business of that sector of the economy. A key question is the scope for increased exports of fresh rather than processed products. Sources of ...

  16. Haemophilia, AIDS and lung epithelial permeability

    Energy Technology Data Exchange (ETDEWEB)

    O' Doherty, M.J.; Page, C.J.; Harrington, C.; Nunan, T.; Savidge, G. (Haemophilia Centre and Coagulation Research Unit, Department of Nuclear Medicine, Rayne Institute, St. Thomas' Hospital, London (United Kingdom))

    1990-01-01

    Lung {sup 99m}Tc DTPA transfer was measured in HIV antibodypositive haemophiliacs (11 smokers, 26 nonsmokers, 5 patients with Pneumocystis carinii pneumonia (PCP)). Lung {sup 99m}Tc DTPA transfer as a marker of lung epithelial permeability was measured as the half time of transfer (from airspace into blood). This half time was faster in smokers compred to nonsmokers and the transfer curve was monoexponential. In nonsmokers no difference was observed between asymptomatic HIV-positive haemophiliacs and normal subjects, with the exception of the lung bases. At the lung basis in HIV-positive haemophiliac nonsmokers the transfer was faster than in normal individuals, implying increased alveolar permeability. Pneumocystis carinii pneumonia resulted in a rapid transfer of {sup 99m}Tc DTPA (mean T50 of 2 minutes) and the transfer curve was biphasic, confirming previous observations in homosexual HIV antibody-positive patients with PCP. These changes returned to a monoexponential profile by 6 weeks following successful treatment. The DTPA lung transfer study may enable clinicians to instigate therapy for PCP without the need for initial bronchoscopy and provide a noninvasive method for the reassessment of patients should further respiratory signs or symptoms develop. This method is considered to be highly cost-effective in that it obviates the use of factor VIII concentrates required to cover bronchoscopic procedures and, with its early application and ease of use as a follow-up investigation, permits the evaluation of patients on an outpatient basis, thus reducing hospital costs. (au).

  17. Haemophilia, AIDS and lung epithelial permeability

    International Nuclear Information System (INIS)

    O'Doherty, M.J.; Page, C.J.; Harrington, C.; Nunan, T.; Savidge, G.

    1990-01-01

    Lung 99m Tc DTPA transfer was measured in HIV antibodypositive haemophiliacs (11 smokers, 26 nonsmokers, 5 patients with Pneumocystis carinii pneumonia (PCP)). Lung 99m Tc DTPA transfer as a marker of lung epithelial permeability was measured as the half time of transfer (from airspace into blood). This half time was faster in smokers compred to nonsmokers and the transfer curve was monoexponential. In nonsmokers no difference was observed between asymptomatic HIV-positive haemophiliacs and normal subjects, with the exception of the lung bases. At the lung basis in HIV-positive haemophiliac nonsmokers the transfer was faster than in normal individuals, implying increased alveolar permeability. Pneumocystis carinii pneumonia resulted in a rapid transfer of 99m Tc DTPA (mean T50 of 2 minutes) and the transfer curve was biphasic, confirming previous observations in homosexual HIV antibody-positive patients with PCP. These changes returned to a monoexponential profile by 6 weeks following successful treatment. The DTPA lung transfer study may enable clinicians to instigate therapy for PCP without the need for initial bronchoscopy and provide a noninvasive method for the reassessment of patients should further respiratory signs or symptoms develop. This method is considered to be highly cost-effective in that it obviates the use of factor VIII concentrates required to cover bronchoscopic procedures and, with its early application and ease of use as a follow-up investigation, permits the evaluation of patients on an outpatient basis, thus reducing hospital costs. (au)

  18. Effect of aggregate grain size distribution on properties of permeable ...

    African Journals Online (AJOL)

    ) ratio on the mechanical properties of permeable concrete is investigated. The aim of this study is to prepare permeable concrete mixture with optimum properties in terms of strength and permeability. For this purpose, five different permeable ...

  19. Climate Change and Thawing Permafrost in Two Iñupiaq Communities of Alaska's Arctic: Observations, Implications, and Resilience

    Science.gov (United States)

    Woodward, A.; Kofinas, G.

    2013-12-01

    For thousands of years the Iñupiat of northern Alaska have relied on ecosystems underlain by permafrost for material and cultural resources. As permafrost thaws across the Arctic, these social-ecological systems are changing rapidly. Community-based research and extensive local knowledge of Iñupiaq villagers offer unique and valuable contributions to understanding permafrost change and its implications for humans. We partnered with two Iñupiaq communities in Alaska's Arctic to investigate current and potential effects of thawing permafrost on social-ecological systems. Anaktuvuk Pass is situated on thaw-stable consolidated gravel in the Brooks Range, while Selawik rests on ice-rich permafrost in Beringia lowland tundra. Using the transdisciplinary approach of resilience theory and mixed geophysical and ethnographic methods, we measured active layer thaw depths and documented local knowledge about climate and permafrost change. Thaw depths were greater overall in Selawik. Residents of both communities reported a variety of changes in surface features, hydrology, weather, flora, and fauna that they attribute to thawing permafrost and / or climate change. Overall, Selawik residents described more numerous and extreme examples of such changes, expressed higher degrees of certainty that change is occurring, and anticipated more significant and negative implications for their way of life than did residents of Anaktuvuk Pass. Of the two villages, Selawik faces greater and more immediate challenges to the resilience of its social-ecological system as permafrost thaws.

  20. Perceptions of Socio-Ecological Changes and Their Implications on Changes in Farming Practises and Agricultural Land Uses in the Savannahs of Northeast Ghana

    Directory of Open Access Journals (Sweden)

    Peter Kojo Boateng

    2016-12-01

    Full Text Available This study assesses the perceptions of local farming households in the savannahs of northeast Ghana about the patterns of ecological and social changes happening around them over the years. It then unpacks how those perceptions are influencing farming practices and agricultural land use changes. Theoretical and empirical understandings of the value of local resource users’ perceptual judgements about changes in their socio-ecological environment and how they respond to those changes have far-reaching implications for design of agricultural development and sustainable land management policies. Consideration of local perceptions offers more informed basis to design and implement agricultural development policies in ways that encourage active local participation, sustainable livelihoods development, and responsiveness to changing conditions. This departs from current conventional implementation systems, which are usually top-down and based on technical and political aspects of agricultural land management, but do not necessarily comprehend processes influencing the agency of local communities in shaping various agricultural land use outcomes.

  1. An integrated approach to permeability modeling using micro-models

    Energy Technology Data Exchange (ETDEWEB)

    Hosseini, A.H.; Leuangthong, O.; Deutsch, C.V. [Society of Petroleum Engineers, Canadian Section, Calgary, AB (Canada)]|[Alberta Univ., Edmonton, AB (Canada)

    2008-10-15

    An important factor in predicting the performance of steam assisted gravity drainage (SAGD) well pairs is the spatial distribution of permeability. Complications that make the inference of a reliable porosity-permeability relationship impossible include the presence of short-scale variability in sand/shale sequences; preferential sampling of core data; and uncertainty in upscaling parameters. Micro-modelling is a simple and effective method for overcoming these complications. This paper proposed a micro-modeling approach to account for sampling bias, small laminated features with high permeability contrast, and uncertainty in upscaling parameters. The paper described the steps and challenges of micro-modeling and discussed the construction of binary mixture geo-blocks; flow simulation and upscaling; extended power law formalism (EPLF); and the application of micro-modeling and EPLF. An extended power-law formalism to account for changes in clean sand permeability as a function of macroscopic shale content was also proposed and tested against flow simulation results. There was close agreement between the model and simulation results. The proposed methodology was also applied to build the porosity-permeability relationship for laminated and brecciated facies of McMurray oil sands. Experimental data was in good agreement with the experimental data. 8 refs., 17 figs.

  2. Climate change and energy: The implications for the Spanish case; Cambio Climatico y Energia: Impliacaciones reciprocas en el caso Espanol

    Energy Technology Data Exchange (ETDEWEB)

    Perez Arriaga, J. I.

    2007-07-01

    This paper examines the mutual implications between the climate change problem and the actual energy-at-a-crossroads situation of the unsustainable world energy model. The implications for the Spanish case are studied as a case example. The paper provides a brief review of the scientific evidence on climate change, analyzes the causes of the present energy dilemma and characterizes the problem to be addressed. The principal challenge for the future climate regime is to identify the nature and level of commitment that will provide sufficient incentives for all countries, with such a diversity of interests. The paper also exposes the most plausible framework for the future climate regime, the basic components of such a regime, the role to be played by the major stake holders and some guidelines for future negotiations. (Author)

  3. Permeability and seismic velocity anisotropy across a ductile-brittle fault zone in crystalline rock

    Science.gov (United States)

    Wenning, Quinn C.; Madonna, Claudio; de Haller, Antoine; Burg, Jean-Pierre

    2018-05-01

    This study characterizes the elastic and fluid flow properties systematically across a ductile-brittle fault zone in crystalline rock at the Grimsel Test Site underground research laboratory. Anisotropic seismic velocities and permeability measured every 0.1 m in the 0.7 m across the transition zone from the host Grimsel granodiorite to the mylonitic core show that foliation-parallel P- and S-wave velocities systematically increase from the host rock towards the mylonitic core, while permeability is reduced nearest to the mylonitic core. The results suggest that although brittle deformation has persisted in the recent evolution, antecedent ductile fabric continues to control the matrix elastic and fluid flow properties outside the mylonitic core. The juxtaposition of the ductile strain zone next to the brittle zone, which is bounded inside the two mylonitic cores, causes a significant elastic, mechanical, and fluid flow heterogeneity, which has important implications for crustal deformation and fluid flow and for the exploitation and use of geothermal energy and geologic waste storage. The results illustrate how physical characteristics of faults in crystalline rocks change in fault zones during the ductile to brittle transitions.

  4. Climate change in the four corners and adjacent regions: Implications for environmental restoration and land-use planning

    Energy Technology Data Exchange (ETDEWEB)

    Waugh, W.J. [ed.

    1995-09-01

    This document contains the workshop proceedings on Climate Change in the Four Corners and Adjacent Regions: Implications for Environmental Restoration and Land-Use Planning which took place September 12-14, 1994 in Grand Junction, Colorado. The workshop addressed three ways we can use paleoenvironmental data to gain a better understanding of climate change and its effects. (1) To serve as a retrospective baseline for interpreting past and projecting future climate-induced environmental change, (2) To differentiate the influences of climate and humans on past environmental change, and (3) To improve ecosystem management and restoration practices in the future. The papers presented at this workshop contained information on the following subjects: Paleoclimatic data from the Pleistocene and Holocene epochs, climate change and past cultures, and ecological resources and environmental restoration. Selected papers are indexed separately for inclusion in the Energy Science and Technology Database.

  5. Permeability of highly compacted bentonite

    International Nuclear Information System (INIS)

    Pusch, R.

    1980-12-01

    The object of the study was the water flow through the bentonite which is caused by hydraulic gradients. The study comprised laboratory tests and theoretical considerations. It was found that high bulk densities reduced the permeability to very low values. It was concluded that practically impervious conditions prevail when the gradients are low. Thus with a regional gradient of 10 -2 and a premeability of 10 -13 m/s the flow rate will not be higher than approximately 1 mm in 30 000 years. (G.B.)

  6. Temperature and Violent Crime in Dallas, Texas: Relationships and Implications of Climate Change

    Directory of Open Access Journals (Sweden)

    Janet L. Gamble

    2012-08-01

    Full Text Available Introduction: To investigate relationships between ambient temperatures and violent crimes to determine whether those relationships are consistent across different crime categories and whether they are best described as increasing linear functions, or as curvilinear functions that decrease beyond some temperature threshold. A secondary objective was to consider the implications of the observed relationships for injuries and deaths from violent crimes in the context of a warming climate. To address these questions, we examined the relationship between daily ambient temperatures and daily incidents of violent crime in Dallas, Texas from 1993–1999.Methods: We analyzed the relationships between daily fluctuations in ambient temperature, other meteorological and temporal variables, and rates of daily violent crime using time series piece-wise regression and plots of daily data. Violent crimes, including aggravated assault, homicide, and sexualassault, were analyzed.Results: We found that daily mean ambient temperature is related in a curvilinear fashion to daily rates of violent crime with a positive and increasing relationship between temperature and aggravated crime that moderates beyond temperatures of 80 F and then turns negative beyond 90 F.Conclusion: While some have characterized the relationship between temperature and violent crime as a continually increasing linear function, leaving open the possibility that aggravated crime will increase in a warmer climate, we conclude that the relationship in Dallas is not linear, but moderatesand turns negative at high ambient temperatures. We posit that higher temperatures may encourage people to seek shelter in cooler indoor spaces, and that street crime and other crimes of opportunity are subsequently decreased. This finding suggests that the higher ambient temperatures expected with climate change may result in marginal shifts in violent crime in the short term, but are not likely to be

  7. A permeability model for coal and other fractured, sorptive-elastic media

    Energy Technology Data Exchange (ETDEWEB)

    Robertson, E.P.; Christiansen, R.L. [Marathon Oil Co., Houston, TX (United States). Research & Development Facility

    2008-09-15

    This paper describes the derivation of a new equation that can be used to model the permeability behavior of a fractured, sorptive-elastic medium, such as coal, under variable stress conditions. The equation is applicable to confinement pressure schemes commonly used during the collection of permeability data in the laboratory. The model is derived for cubic geometry under biaxial or hydrostatic confining pressures. The model is designed to handle changes in permeability caused by adsorption and desorption of gases onto and from the matrix blocks in fractured media. The model equations can be used to calculate permeability changes caused by the production of methane (CH{sub 4}) from coal as well as the injection of gases, such as carbon dioxide, for sequestration in coal. Sensitivity analysis of the model found that each of the input variables can have a significant impact on the outcome of the permeability forecast as a function of changing pore pressure, thus, accurate input data are essential. The permeability model also can be used as a tool to determine input parameters for field simulations by curve fitting laboratory-generated permeability data. The new model is compared to two other widely used coal-permeability models using a hypothetical coal with average properties.

  8. The effect of offset on fracture permeability of rocks from the Southern Andes Volcanic Zone, Chile

    Science.gov (United States)

    Pérez-Flores, P.; Wang, G.; Mitchell, T. M.; Meredith, P. G.; Nara, Y.; Sarkar, V.; Cembrano, J.

    2017-11-01

    The Southern Andes Volcanic Zone (SVZ) represents one of the largest undeveloped geothermal provinces in the world. Development of the geothermal potential requires a detailed understanding of fluid transport properties of its main lithologies. The permeability of SVZ rocks is altered by the presence of fracture damage zones produced by the Liquiñe-Ofqui Fault System (LOFS) and the Andean Transverse Faults (ATF). We have therefore measured the permeability of four representative lithologies from the volcanic basement in this area: crystalline tuff, andesitic dike, altered andesite and granodiorite. For comparative purposes, we have also measured the permeability of samples of Seljadalur basalt, an Icelandic rock with widely studied and reported hydraulic properties. Specifically, we present the results of a systematic study of the effect of fractures and fracture offsets on permeability as a function of increasing effective pressure. Baseline measurements on intact samples of SVZ rocks show that the granodiorite has a permeability (10-18 m2), two orders of magnitude higher than that of the volcanic rocks (10-20 m2). The presence of throughgoing mated macro-fractures increases permeability by between four and six orders of magnitude, with the highest permeability recorded for the crystalline tuff. Increasing fracture offset to produce unmated fractures results in large increases in permeability up to some characteristic value of offset, beyond which permeability changes only marginally. The increase in permeability with offset appears to depend on fracture roughness and aperture, and these are different for each lithology. Overall, fractured SVZ rocks with finite offsets record permeability values consistent with those commonly found in geothermal reservoirs (>10-16 m2), which potentially allow convective/advective flow to develop. Hence, our results demonstrate that the fracture damage zones developed within the SVZ produce permeable regions, especially within the

  9. Effective permeability in micropores from molecular simulations

    International Nuclear Information System (INIS)

    Botan, A.; Vermorel, R.; Brochard, L.; Hantal, G.; Pellenq, R.

    2012-01-01

    Document available in extended abstract form only. Despite many years' efforts and a large numbers of proposed models, the description of transport properties in clays is still an open question. The reason for this is that structurally clay is an extremely heterogeneous material. The pore size varies from a few to 20 angstroms for interlayer (micro) porosity, from 20 A to 500 A for interparticle (meso) porosity, and 500 A to μm and more for natural (macro) fractures. One further problem with the description of the transport properties is the presence of adsorption/desorption processes onto clay particles, which are coupled with swelling/shrinkage of the particles. Any volumetric changes in the particles affect the meso-pore aperture, and thus, the total permeability of the system. The various processes affecting the permeability occur on different spatial and temporal scales, that requires a multi-scale modeling approach. The most complete model to date is a dual porosity mode. Here the total flow is often written as a sum of the macropore flow and micropore flow. The flow through macro-pores is generally considered to be laminar and obeys Darcy's law, whereas flow through the matrix (micropore flow) may be modeled using Fick's law. The micropore flow involves both Knudsen and surface diffusion mechanisms. An accurate accounting of adsorption-desorption processes or the consideration of binary mixture greatly complicate analytical description. The goal of this study is to improve macro-scale model, the dual porosity model, for the transport properties of fluids in micropores from molecular simulations. The main idea is that we reproduce an experimental set-up used for permeability measurements, as illustrated in Figure 1. High density and low density regions are settled at each end of the membrane that allows to attain a steady flow. The densities in these regions are controlled by Grand Canonical Monte Carlo simulation; the molecular motions are described by

  10. Steam-water relative permeability

    Energy Technology Data Exchange (ETDEWEB)

    Ambusso, W.; Satik, C.; Home, R.N. [Stanford Univ., CA (United States)

    1997-12-31

    A set of relative permeability relations for simultaneous flow of steam and water in porous media have been measured in steady state experiments conducted under the conditions that eliminate most errors associated with saturation and pressure measurements. These relations show that the relative permeabilities for steam-water flow in porous media vary approximately linearly with saturation. This departure from the nitrogen/water behavior indicates that there are fundamental differences between steam/water and nitrogen/water flows. The saturations in these experiments were measured by using a high resolution X-ray computer tomography (CT) scanner. In addition the pressure gradients were obtained from the measurements of liquid phase pressure over the portions with flat saturation profiles. These two aspects constitute a major improvement in the experimental method compared to those used in the past. Comparison of the saturation profiles measured by the X-ray CT scanner during the experiments shows a good agreement with those predicted by numerical simulations. To obtain results that are applicable to general flow of steam and water in porous media similar experiments will be conducted at higher temperature and with porous rocks of different wetting characteristics and porosity distribution.

  11. DECOVALEX-THMC Project. Task D. Long-Term Permeability/Porosity Changes in the EDZ and Near Field due to THM and THC Processes in Volcanic and Crystalline-Bentonite Systems. Phase 1 Report

    International Nuclear Information System (INIS)

    Birkholzer, J.; Rutqvist, J.; Sonnenthal, E.; Barr, D.

    2007-02-01

    The general goal of this project is to encourage multidisciplinary interactive and cooperative research on modeling coupled processes in geologic formations in support of the performance assessment for underground storage of radioactive waste. Three multi-year project stages of DECOVALEX have been completed in the past decade, mainly focusing on coupled thermal-hydrological-mechanical processes. Currently, a fourth three-year project stage of DECOVALEX is under way, referred to as DECOVALEX-THMC. THMC stands for Thermal, Hydrological, Mechanical, and Chemical processes. The new project stage aims at expanding the traditional geomechanical scope of the previous DECOVALEX project stages by incorporating geochemical processes important for repository performance. The U.S. Department of Energy (DOE) leads Task D of the new DECOVALEX phase, entitled 'Long-term Permeability/Porosity Changes in the EDZ and Near Field due to THC and THM Processes for Volcanic and Crystalline-Bentonite Systems.' In its leadership role for Task D, DOE coordinates and sets the direction for the cooperative research activities of the international research teams engaged in Task D. The research program developed for Task D of DECOVALEX-THMC involves geomechanical and geochemical research areas. THM and THC processes may lead to changes in hydrological properties that are important for performance because the flow processes in the vicinity of emplacement tunnels will be altered from their initial state. Some of these changes can be permanent (irreversible), in which case they persist after the thermal conditions have returned to ambient; i.e., they will affect the entire regulatory compliance period. Geochemical processes also affect the water and gas chemistry close to the waste packages, which are relevant for waste package corrosion, buffer stability, and radionuclide transport. Research teams participating in Task D evaluate long-term THM and THC processes in two generic geologic

  12. DECOVALEX-THMC Project. Task D. Long-Term Permeability/Porosity Changes in the EDZ and Near Field due to THM and THC Processes in Volcanic and Crystalline-Bentonite Systems. Phase 1 Report

    Energy Technology Data Exchange (ETDEWEB)

    Birkholzer, J.; Rutqvist, J.; Sonnenthal, E. [Lawrence Berkeley National Laboratory, CA (United States); Barr, D. [Office of Repository Development, DOE (United States)

    2007-02-15

    The general goal of this project is to encourage multidisciplinary interactive and cooperative research on modeling coupled processes in geologic formations in support of the performance assessment for underground storage of radioactive waste. Three multi-year project stages of DECOVALEX have been completed in the past decade, mainly focusing on coupled thermal-hydrological-mechanical processes. Currently, a fourth three-year project stage of DECOVALEX is under way, referred to as DECOVALEX-THMC. THMC stands for Thermal, Hydrological, Mechanical, and Chemical processes. The new project stage aims at expanding the traditional geomechanical scope of the previous DECOVALEX project stages by incorporating geochemical processes important for repository performance. The U.S. Department of Energy (DOE) leads Task D of the new DECOVALEX phase, entitled 'Long-term Permeability/Porosity Changes in the EDZ and Near Field due to THC and THM Processes for Volcanic and Crystalline-Bentonite Systems.' In its leadership role for Task D, DOE coordinates and sets the direction for the cooperative research activities of the international research teams engaged in Task D. The research program developed for Task D of DECOVALEX-THMC involves geomechanical and geochemical research areas. THM and THC processes may lead to changes in hydrological properties that are important for performance because the flow processes in the vicinity of emplacement tunnels will be altered from their initial state. Some of these changes can be permanent (irreversible), in which case they persist after the thermal conditions have returned to ambient; i.e., they will affect the entire regulatory compliance period. Geochemical processes also affect the water and gas chemistry close to the waste packages, which are relevant for waste package corrosion, buffer stability, and radionuclide transport. Research teams participating in Task D evaluate long-term THM and THC processes in two generic geologic

  13. Thermomechanical effects on permeability for a 3-D model of YM rock

    International Nuclear Information System (INIS)

    Berge, P A; Blair, S C; Wang, H F

    1999-01-01

    The authors estimate how thermomechanical processes affect the spatial variability of fracture permeability for a 3-D model representing Topopah Spring tuff at the nuclear-waste repository horizon in Yucca Mountain, Nevada. Using a finite-difference code, they compute thermal stress changes. They evaluate possible permeability enhancement resulting from shear slip along various mapped fracture sets after 50 years of heating, for rock in the near-field environment of the proposed repository. The results indicate permeability enhancement of a factor of 2 for regions about 10 to 30 m above drifts, for north-south striking vertical fractures. Shear slip and permeability increases of a factor of 4 can occur in regions just above drifts, for east-west striking vertical fractures. Information on how permeability may change over the lifetime of a geologic repository is important to the prediction and evaluation of repository performance

  14. Acute changes in clinical breast measurements following bra removal: Implications for surgical practice

    Directory of Open Access Journals (Sweden)

    Joanna Scurr

    2015-03-01

    Conclusions: Internipple distance and breast projection can be measured first following bra removal, followed by sternal notch to nipple distance, any measures associated with the vertical nipple position should be made more than 6 min after bra removal. These guidelines have implications for breast surgery, particularly for unilateral reconstruction based on the residual breast position.

  15. Identification of two distinct fire regimes in Southern California: implications for economic impact and future change

    Science.gov (United States)

    Yufang Jin; Michael L. Goulden; Nicolas Faivre; Sander Veraverbeke; Fengpeng Sun; Alex Hall; Michael S. Hand; Simon Hook; James T. Randerson

    2015-01-01

    The area burned by Southern California wildfires has increased in recent decades, with implications for human health, infrastructure, and ecosystem management. Meteorology and fuel structure are universally recognized controllers of wildfire, but their relative importance, and hence the efficacy of abatement and suppression efforts, remains controversial....

  16. Clogging in permeable concrete: A review.

    Science.gov (United States)

    Kia, Alalea; Wong, Hong S; Cheeseman, Christopher R

    2017-05-15

    Permeable concrete (or "pervious concrete" in North America) is used to reduce local flooding in urban areas and is an important sustainable urban drainage system. However, permeable concrete exhibits reduction in permeability due to clogging by particulates, which severely limits service life. This paper reviews the clogging mechanism and current mitigating strategies in order to inform future research needs. The pore structure of permeable concrete and characteristics of flowing particulates influence clogging, which occurs when particles build-up and block connected porosity. Permeable concrete requires regular maintenance by vacuum sweeping and pressure washing, but the effectiveness and viability of these methods is questionable. The potential for clogging is related to the tortuosity of the connected porosity, with greater tortuosity resulting in increased potential for clogging. Research is required to develop permeable concrete that can be poured on-site, which produces a pore structure with significantly reduced tortuosity. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Different Methods of Predicting Permeability in Shale

    DEFF Research Database (Denmark)

    Mbia, Ernest Ncha; Fabricius, Ida Lykke; Krogsbøll, Anette

    by two to five orders of magnitudes at lower vertical effective stress below 40 MPa as the content of clay minerals increases causing heterogeneity in shale material. Indirect permeability from consolidation can give maximum and minimum values of shale permeability needed in simulating fluid flow......Permeability is often very difficult to measure or predict in shale lithology. In this work we are determining shale permeability from consolidation tests data using Wissa et al., (1971) approach and comparing the results with predicted permeability from Kozeny’s model. Core and cuttings materials...... effective stress to 9 μD at high vertical effective stress of 100 MPa. The indirect permeability calculated from consolidation tests falls in the same magnitude at higher vertical effective stress, above 40 MPa, as that of the Kozeny model for shale samples with high non-clay content ≥ 70% but are higher...

  18. Potential Implications of Approaches to Climate Change on the Clean Water Rule Definition of "Waters of the United States".

    Science.gov (United States)

    Faust, Derek R; Moore, Matthew T; Emison, Gerald Andrews; Rush, Scott A

    2016-05-01

    The 1972 Clean Water Act was passed to protect chemical, physical, and biological integrity of United States' waters. The U.S. Environmental Protection Agency and U.S. Army Corps of Engineers codified a new "waters of the United States" rule on June 29, 2015, because several Supreme Court case decisions caused confusion with the existing rule. Climate change could affect this rule through connectivity between groundwater and surface waters; floodplain waters and the 100-year floodplain; changes in jurisdictional status; and sea level rise on coastal ecosystems. Four approaches are discussed for handling these implications: (1) "Wait and see"; (2) changes to the rule; (3) use guidance documents; (4) Congress statutorily defining "waters of the United States." The approach chosen should be legally defensible and achieved in a timely fashion to provide protection to "waters of the United States" in proactive consideration of scientifically documented effects of climate change on aquatic ecosystems.

  19. The Land Use and Cover Change in Miombo Woodlands under Community Based Forest Management and Its Implication to Climate Change Mitigation: A Case of Southern Highlands of Tanzania

    Directory of Open Access Journals (Sweden)

    Z. J. Lupala

    2015-01-01

    Full Text Available In Tanzania, miombo woodland is the most significant forest vegetation with both ecological and socioeconomic importance. The vegetation has been threatened from land use and cover change due to unsustainable utilization. Over the past two decades, community based forest management (CBFM has been practiced to address the problem. Given the current need to mitigate global climate change, little is known on the influence of CBFM to the land use and cover change in miombo woodlands and therefore compromising climate change mitigation strategies. This study explored the dynamic of land use and covers change and biomass due to CBFM and established the implication to climate change mitigation. The study revealed increasing miombo woodland cover density with decreasing unsustainable utilization. The observed improvement in cover density and biomass provides potential for climate change mitigation strategies. CBFM also developed solidarity, cohesion, and social control of miombo woodlands illegal extraction. This further enhances permanence, reduces leakage, and increases accountability requirement for carbon credits. Collectively with these promising results, good land use plan at village level and introduction of alternative income generating activities can be among the best options to further reduce land use change and biomass loss in miombo woodlands.

  20. Low Permeability Polyimide Insulation, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Resodyn Technologies proposes a new technology that enables the application of polyimide based cryogenic insulation with low hydrogen permeability. This effort...

  1. Modelling of water permeability in cementitious materials

    DEFF Research Database (Denmark)

    Guang, Ye; Lura, Pietro; van Breugel, K.

    2006-01-01

    This paper presents a network model to predict the permeability of cement paste from a numerical simulation of its microstructure. Based on a linked list pore network structure, the effective hydraulic conductivity is estimated and the fluid flow is calculated according to the Hagen-Poiseuille law....... The pressure gradient at all nodes is calculated with the Gauss elimination method and the absolute permeability of the pore network is calculated directly from Darcy's law. Finally, the permeability model is validated by comparison with direct water permeability measurements. According to this model...

  2. Wildlife management in Gonarezhou National Park, southeast Zimbabwe: Climate change and implications for management

    NARCIS (Netherlands)

    Gandiwa, E.; Zisadza, P.

    2010-01-01

    Climate change is not a new phenomenon; the only constant about climate throughout Earth’s history is that it has changed (Marchant, 2010). An earlier study in Africa indicated that some Southern African ecosystems are highly sensitive to climate change (e.g., Magadza, 1994). Climate change in

  3. Economy-Wide estimates of the implications of climate change: Human health

    NARCIS (Netherlands)

    Bosello, F.; Roson, R.; Tol, R.S.J.

    2006-01-01

    We study the economic impacts of climate-change-induced change in human health, viz. cardiovascular and respiratory disorders, diarrhoea, malaria, dengue fever and schistosomiasis. Changes in morbidity and mortality are interpreted as changes in labour productivity and demand for health care, and

  4. Conceptualizing Climate Change in the Context of a Climate System: Implications for Climate and Environmental Education

    Science.gov (United States)

    Shepardson, Daniel P.; Niyogi, Dev; Roychoudhury, Anita; Hirsch, Andrew

    2012-01-01

    Today there is much interest in teaching secondary students about climate change. Much of this effort has focused directly on students' understanding of climate change. We hypothesize, however, that in order for students to understand climate change they must first understand climate as a system and how changes to this system due to both natural…

  5. Individual Readiness for Organizational Change and Its Implications for Human Resource and Organization Development

    Science.gov (United States)

    Choi, Myungweon; Ruona, Wendy E. A.

    2011-01-01

    Individual readiness for organizational change reflects the concept of "unfreezing" proposed by Lewin (1947/1997b) and is critical to successful change implementation. Understanding the conditions conducive to individual readiness for organizational change, instead of the more traditional focus on resistance to change, can be useful for designing…

  6. Communication, sensemaking and change as a chord of three strands: Practical implications and a research agenda for communicating organizational change

    NARCIS (Netherlands)

    van Vuuren, M.; Elving, W.J.L.

    2008-01-01

    Purpose - The paper aims to propose practical and theoretical consequences of emerging lines of thinking about communication during organizational change. Design/methodology/approach - This conceptual paper suggests several benefits that a sensemaking approach may have in enhancing organizational

  7. Changes in vegetation in northern Alaska under scenarios of climate change, 2003-2100: implications for climate feedbacks

    Science.gov (United States)

    Euskirchen, Eugénie S.; McGuire, Anthony David; Chapin, F. Stuart; Yi, S.; Thompson, Catharine Copass

    2009-01-01

    Assessing potential future changes in arctic and boreal plant species productivity, ecosystem composition, and canopy complexity is essential for understanding environmental responses under expected altered climate forcing. We examined potential changes in the dominant plant functional types (PFTs) of the sedge tundra, shrub tundra, and boreal forest ecosystems in ecotonal northern Alaska, USA, for the years 2003–2100. We compared energy feedbacks associated with increases in biomass to energy feedbacks associated with changes in the duration of the snow-free season. We based our simulations on nine input climate scenarios from the Intergovernmental Panel on Climate Change (IPCC) and a new version of the Terrestrial Ecosystem Model (TEM) that incorporates biogeochemistry, vegetation dynamics for multiple PFTs (e.g., trees, shrubs, grasses, sedges, mosses), multiple vegetation pools, and soil thermal regimes. We found mean increases in net primary productivity (NPP) in all PFTs. Most notably, birch (Betula spp.) in the shrub tundra showed increases that were at least three times larger than any other PFT. Increases in NPP were positively related to increases in growing-season length in the sedge tundra, but PFTs in boreal forest and shrub tundra showed a significant response to changes in light availability as well as growing-season length. Significant NPP responses to changes in vegetation uptake of nitrogen by PFT indicated that some PFTs were better competitors for nitrogen than other PFTs. While NPP increased, heterotrophic respiration (RH) also increased, resulting in decreases or no change in net ecosystem carbon uptake. Greater aboveground biomass from increased NPP produced a decrease in summer albedo, greater regional heat absorption (0.34 ± 0.23 W·m−2·10 yr−1 [mean ± SD]), and a positive feedback to climate warming. However, the decrease in albedo due to a shorter snow season (−5.1 ± 1.6 d/10 yr) resulted in much greater regional heat

  8. Consolidation and permeability of salt in brine

    International Nuclear Information System (INIS)

    Shor, A.J.; Baes, C.F. Jr.; Canonico, C.M.

    1981-07-01

    The consolidation and loss of permeability of salt crystal aggregates, important in assessing the effects of water in salt repositories, has been studied as a function of several variables. The kinetic behavior was similar to that often observed in sintering and suggested the following expression for the time dependence of the void fraction: phi(t) = phi(0) - (A/B)ln(1 + Bt/z(0) 3 ), where A and B are rate constants and z(0) is initial average particle size. With brine present, A and phi(0) varied linearly with stress. The initial void fraction was also dependent to some extent on the particle size distribution. The rate of consolidation was most rapid in brine and least rapid in the presence of only air as the fluid. A brine containing 5 m MgCl 2 showed an intermediate rate, presumably because of the greatly reduced solubility of NaCl. A substantial wall effect was indicated by an observed increase in the void fraction of consolidated columns with distance from the top where the stress was applied and by a dependence of consolidation rate on the column height and radius. The distance through which the stress fell by a factor of phi was estimated to change inversely as the fourth power of the column diameter. With increasing temperature (to 85 0 C), consolidation proceeded somewhat more rapidly and the wall effect was reduced. The permeability of the columns dropped rapidly with consolidation, decreasing with about the sixth power of the void fraction. In general, extrapolation of the results to repository conditions confirms the self-sealing properties of bedded salt as a storage medium for radioactive waste

  9. Changes in the land use in the valley of Escaba (Province of Tucuman, Argentina) and their environmental implications

    International Nuclear Information System (INIS)

    Guido, E.; Sesma, P.

    2010-01-01

    The objective of this work was to evaluate changes in the land use due to the construction of a dam and reservoir in the valley of Escaba, located southwest of the province of Tucuman ( north of Argentina ) and its implications for the atmosphere. Aerial photographs and satellite images were used for the study. The results show changes in the drainage network of rivers flowing into the center of the valley, changes in base levels and the formation of wetlands of high ecological, social and economic values. The existence of archaeological sites, some of which remain under water and crop areas that have expanded into both riverbanks stands . The enclosure of the valley caused large areas of land disappear under water, altering not only the landscape but also land use and lifestyle of the population, much of which had to be relocated to higher areas

  10. Resource limits and conversion efficiency with implications for climate change and California's energy supply

    Science.gov (United States)

    Croft, Gregory Donald

    There are two commonly-used approaches to modeling the future supply of mineral resources. One is to estimate reserves and compare the result to extraction rates, and the other is to project from historical time series of extraction rates. Perceptions of abundant oil supplies in the Middle East and abundant coal supplies in the United States are based on the former approach. In both of these cases, an approach based on historical production series results in a much smaller resource estimate than aggregate reserve numbers. This difference is not systematic; natural gas production in the United States shows a strong increasing trend even though modest reserve estimates have resulted in three decades of worry about the gas supply. The implication of a future decline in Middle East oil production is that the market for transportation fuels is facing major changes, and that alternative fuels should be analyzed in this light. Because the U.S. holds very large coal reserves, synthesizing liquid hydrocarbons from coal has been suggested as an alternative fuel supply. To assess the potential of this process, one has to look at both the resource base and the net efficiency. The three states with the largest coal production declines in the 1996 to 2006 period are among the top 5 coal reserve holders, suggesting that gross coal reserves are a poor indicator of future production. Of the three categories of coal reserves reported by the U.S. Energy Information Administration, reserves at existing mines is the narrowest category and is approximately the equivalent of proved developed oil reserves. By this measure, Wyoming has the largest coal reserves in the U.S., and it accounted for all of U.S. coal production growth over the 1996 to 2006 time period. In Chapter 2, multi-cycle Hubbert curve analysis of historical data of coal production from 1850 to 2007 demonstrates that U.S. anthracite and bituminous coal are past their production peak. This result contradicts estimates based

  11. Effect of climate change on crop production patterns with implications to transport flows and inland waterways.

    Science.gov (United States)

    2011-12-01

    This project analyzed the demand for transportation capacity and changes in transportation flows on : inland waterways due to shifts in crop production patterns induced by climate change. Shifts in the crop : production mix have been observed in rece...

  12. Changes in Canada pension plan disability rules hold implications for physicians.

    Science.gov (United States)

    Romaniuk, A

    1995-12-15

    Recent legislative changes to the Canada Pension Plan (CPP) have significantly altered eligibility requirements for disability pensions. A CPP medical adviser explains how the changes affect physicians and examines the federal government's definition of "disability."

  13. Global change-driven effects on dissolved organic matter composition: Implications for food webs of northern lakes.

    Science.gov (United States)

    Creed, Irena F; Bergström, Ann-Kristin; Trick, Charles G; Grimm, Nancy B; Hessen, Dag O; Karlsson, Jan; Kidd, Karen A; Kritzberg, Emma; McKnight, Diane M; Freeman, Erika C; Senar, Oscar E; Andersson, Agneta; Ask, Jenny; Berggren, Martin; Cherif, Mehdi; Giesler, Reiner; Hotchkiss, Erin R; Kortelainen, Pirkko; Palta, Monica M; Vrede, Tobias; Weyhenmeyer, Gesa A

    2018-03-15

    Northern ecosystems are experiencing some of the most dramatic impacts of global change on Earth. Rising temperatures, hydrological intensification, changes in atmospheric acid deposition and associated acidification recovery, and changes in vegetative cover are resulting in fundamental changes in terrestrial-aquatic biogeochemical linkages. The effects of global change are readily observed in alterations in the supply of dissolved organic matter (DOM)-the messenger between terrestrial and lake ecosystems-with potentially profound effects on the structure and function of lakes. Northern terrestrial ecosystems contain substantial stores of organic matter and filter or funnel DOM, affecting the timing and magnitude of DOM delivery to surface waters. This terrestrial DOM is processed in streams, rivers, and lakes, ultimately shifting its composition, stoichiometry, and bioavailability. Here, we explore the potential consequences of these global change-driven effects for lake food webs at northern latitudes. Notably, we provide evidence that increased allochthonous DOM supply to lakes is overwhelming increased autochthonous DOM supply that potentially results from earlier ice-out and a longer growing season. Furthermore, we assess the potential implications of this shift for the nutritional quality of autotrophs in terms of their stoichiometry, fatty acid composition, toxin production, and methylmercury concentration, and therefore, contaminant transfer through the food web. We conclude that global change in northern regions leads not only to reduced primary productivity but also to nutritionally poorer lake food webs, with discernible consequences for the trophic web to fish and humans. © 2018 John Wiley & Sons Ltd.

  14. Contextual Change After Fear Acquisition Affects Conditioned Responding and the Time Course of Extinction Learning-Implications for Renewal Research.

    Science.gov (United States)

    Sjouwerman, Rachel; Niehaus, Johanna; Lonsdorf, Tina B

    2015-01-01

    Context plays a central role in retrieving (fear) memories. Accordingly, context manipulations are inherent to most return of fear (ROF) paradigms (in particular renewal), involving contextual changes after fear extinction. Context changes are, however, also often embedded during earlier stages of ROF experiments such as context changes between fear acquisition and extinction (e.g., in ABC and ABA renewal). Previous studies using these paradigms have however focused exclusively on the context switch after extinction (i.e., renewal). Thus, the possibility of a general effect of context switch on conditioned responding that may not be conditional to preceding extinction learning remains unstudied. Hence, the current study investigated the impact of a context switch between fear acquisition and extinction on immediate conditioned responding and on the time-course of extinction learning by using a multimodal approach. A group that underwent contextual change after fear conditioning (AB; n = 36) was compared with a group without a contextual change from acquisition to extinction (AA; n = 149), while measuring physiological (skin conductance and fear potentiated startle) measures and subjective fear ratings. Contextual change between fear acquisition and extinction had a pronounced effect on both immediate conditioned responding and on the time course of extinction learning in skin conductance responses and subjective fear ratings. This may have important implications for the mechanisms underlying and the interpretation of the renewal effect (i.e., contextual switch after extinction). Consequently, future studies should incorporate designs and statistical tests that disentangle general effects of contextual change from genuine ROF effects.

  15. PLVAP in diabetic retinopathy: A gatekeeper of angiogenesis and vascular permeability

    NARCIS (Netherlands)

    Wiśniewska-Kruk, J.

    2014-01-01

    Nowadays, approximately 4 million people worldwide experience blindness or severe vision loss caused by diabetic retinopathy. Diabetic retinopathy is a multifactorial disease that can progress from minor changes in vascular permeability, into a proliferative retinal disorder. The increasing

  16. Permeability of volcanic rocks to gas and water

    Science.gov (United States)

    Heap, M. J.; Reuschlé, T.; Farquharson, J. I.; Baud, P.

    2018-04-01

    The phase (gas or liquid) of the fluids within a porous volcanic system varies in both time and space. Laboratory experiments have shown that gas and water permeabilities can differ for the same rock sample, but experiments are biased towards rocks that contain minerals that are expected react with the pore fluid (such as the reaction between liquid water and clay). We present here the first study that systematically compares the gas and water permeability of volcanic rocks. Our data show that permeabilities to argon gas and deionised water can differ by a factor between two and five in two volcanic rocks (basalt and andesite) over a confining pressure range from 2 to 50 MPa. We suggest here that the microstructural elements that offer the shortest route through the sample-estimated to have an average radius 0.1-0.5 μm using the Klinkenberg slip factor-are accessible to gas, but restricted or inaccessible to water. We speculate that water adsorption on the surface of these thin microstructural elements, assumed here to be tortuous/rough microcracks, reduces their effective radius and/or prevents access. These data have important implications for fluid flow and therefore the distribution and build-up of pore pressure within volcanic systems.

  17. Changes in the Nature and Structure of Work: Implications for Skill Requirements and Skill Formation.

    Science.gov (United States)

    Bailey, Thomas

    Changes in the economy and the workplace are changing job skill requirements and the process of skill acquisition. A study analyzed occupational trends and projections, performed case studies of four industry sectors (apparel and textile, accounting, management consulting, and software development), and reviewed research on changing skill demands…

  18. Total Teacher Effectiveness: Implication for Curriculum Change (TOC) in Hong Kong.

    Science.gov (United States)

    Tsui, Kwok Tung; Cheng, Yin Cheong

    This paper introduces the concept of total teacher effectiveness for facilitating educational reform and improvement, using target oriented curriculum (TOC) change in Hong Kong as an example. TOC change is a complex process that involves preparing, changing, and reinforcing teachers in multiple domains at multiple levels. Teacher effectiveness…

  19. Rural Households’ Adaptation to Climate Change and its Implications for Policy Designs in Lijiang, China

    DEFF Research Database (Denmark)

    Zheng, Yuan

    changes in social-ecological systems. The PhD research demonstrates 1) the interwoven impacts of co-evolving socio-economic, political and environmental changes in shaping livelihood changes and households’ vulnerability; 2) the usefulness to accommodate key cognitive processes, such as risk perception...... to assist climate risk management are essential....

  20. Economy-wide estimates of the implications of climate change. Human health

    Energy Technology Data Exchange (ETDEWEB)

    Bosello, Francesco [Fondazione Eni Enrico Mattei, Venice (Italy); Roson, Roberto [International Centre for Theoretical Physics, Trieste (Italy); Tol, Richard S.J. [Centre for Marine and Climate Research, Hamburg University, Hamburg (Germany)

    2006-06-25

    We study the economic impacts of climate-change-induced change in human health, viz. cardiovascular and respiratory disorders, diarrhoea, malaria, dengue fever and schistosomiasis. Changes in morbidity and mortality are interpreted as changes in labour productivity and demand for health care, and used to shock the GTAP-E computable general equilibrium model, calibrated for the year 2050. GDP, welfare and investment fall (rise) in regions with net negative (positive) health impacts. Prices, production, and terms of trade show a mixed pattern. Direct cost estimates, common in climate change impact studies, underestimate the true welfare losses. (author)

  1. Hotspots of climate change impacts in sub-Saharan Africa and implications for adaptation and development.

    Science.gov (United States)

    Müller, Christoph; Waha, Katharina; Bondeau, Alberte; Heinke, Jens

    2014-08-01

    Development efforts for poverty reduction and food security in sub-Saharan Africa will have to consider future climate change impacts. Large uncertainties in climate change impact assessments do not necessarily complicate, but can inform development strategies. The design of development strategies will need to consider the likelihood, strength, and interaction of climate change impacts across biosphere properties. We here explore the spread of climate change impact projections and develop a composite impact measure to identify hotspots of climate change impacts, addressing likelihood and strength of impacts. Overlapping impacts in different biosphere properties (e.g. flooding, yields) will not only claim additional capacity to respond, but will also narrow the options to respond and develop. Regions with severest projected climate change impacts often coincide with regions of high population density and poverty rates. Science and policy need to propose ways of preparing these areas for development under climate change impacts. © 2014 John Wiley & Sons Ltd.

  2. Permeability of Aluminium Foams Produced by Replication Casting

    Directory of Open Access Journals (Sweden)

    Maxim L. Cherny

    2012-12-01

    Full Text Available The replication casting process is used for manufacturing open-pore aluminum foams with advanced performances, such as stability and repeatability of foam structure with porosity over 60%. A simple foam structure model based on the interaction between sodium chloride solid particles poorly wetted by melted aluminum, which leads to the formation of air pockets (or “air collars”, is proposed for the permeability of porous material. The equation for the minimum pore radius of replicated aluminum foam is derived. According to the proposed model, the main assumption of the permeability model consists in a concentration of flow resistance in a circular aperture of radius rmin. The permeability of aluminum open-pore foams is measured using transformer oil as the fluid, changing the fractions of initial sodium chloride. Measured values of minimum pore size are close to theoretically predicted ones regardless of the particle shape. The expression for the permeability of replicated aluminum foam derived on the basis of the “bottleneck” model of porous media agrees well with the experimental data. The obtained data can be applied for commercial filter cells and pneumatic silencers.

  3. Optimizing solubility and permeability of a biopharmaceutics classification system (BCS) class 4 antibiotic drug using lipophilic fragments disturbing the crystal lattice.

    Science.gov (United States)

    Tehler, Ulrika; Fagerberg, Jonas H; Svensson, Richard; Larhed, Mats; Artursson, Per; Bergström, Christel A S

    2013-03-28

    Esterification was used to simultaneously increase solubility and permeability of ciprofloxacin, a biopharmaceutics classification system (BCS) class 4 drug (low solubility/low permeability) with solid-state limited solubility. Molecular flexibility was increased to disturb the crystal lattice, lower the melting point, and thereby improve the solubility, whereas lipophilicity was increased to enhance the intestinal permeability. These structural changes resulted in BCS class 1 analogues (high solubility/high permeability) emphasizing that simple medicinal chemistry may improve both these properties.

  4. Microorganism Removal in Permeable Pavement Parking Lots ...

    Science.gov (United States)

    Three types of permeable pavements (pervious concrete, permeable interlocking concrete pavers, and porous asphalt) were monitored at the Edison Environmental Center in Edison, New Jersey for indicator organisms such as fecal coliform, enterococci, and E. coli. Results showed that porous asphalt had much lower concentration in monitored infiltrate compared to pervious concrete and permeable interlocking concrete pavers. Concentrations of monitored organisms in infiltrate from porous asphalt were consistently below the bathing water quality standard. Fecal coliform and enterococci exceeded bathing water quality standards more than 72% and 34% of the time for permeable interlocking concrete pavers and pervious concrete, respectively. Purpose is to evaluate the performance of permeable pavement in removing indicator organisms from infiltrating stormwater runoff.

  5. [Clinical Implications of Changes in Child Psychiatry in the DSM-5. Strengths and Weaknesses of the Changes].

    Science.gov (United States)

    Botero-Franco, Diana; Palacio-Ortíz, Juan David; Arroyave-Sierra, Pilar; Piñeros-Ortíz, Sandra

    2016-01-01

    The Diagnostic and Statistical Manual of Mental Disorders (DSM) and the International Statistical Classification of Diseases and related health problems (ICD) integrate the diagnostic criteria commonly used in psychiatric practice, but the DSM-IV-TR was insufficient for current clinical work. The DSM-5 was first made public in May at the Congress of the American Psychiatric Association, and it includes changes to some aspects of Child Psychiatry, as many of the conditions that were at the beginning in chapter of infancy, childhood and adolescence disorders have been transferred to other chapters and there are new diagnostic criteria or new terms are added. It is therefore important to provide it to Psychiatrists who attend children in order to assess the changes they will be facing in the nomenclature and classification in pursuit of a better classification of the childhood psychopathology. Copyright © 2016. Publicado por Elsevier España.

  6. Global analysis of approaches for deriving total water storage changes from GRACE satellites and implications for groundwater storage change estimation

    Science.gov (United States)

    Long, D.; Scanlon, B. R.; Longuevergne, L.; Chen, X.

    2015-12-01

    Increasing interest in use of GRACE satellites and a variety of new products to monitor changes in total water storage (TWS) underscores the need to assess the reliability of output from different products. The objective of this study was to assess skills and uncertainties of different approaches for processing GRACE data to restore signal losses caused by spatial filtering based on analysis of 1°×1° grid scale data and basin scale data in 60 river basins globally. Results indicate that scaling factors from six land surface models (LSMs), including four models from GLDAS-1 (Noah 2.7, Mosaic, VIC, and CLM 2.0), CLM 4.0, and WGHM, are similar over most humid, sub-humid, and high-latitude regions but can differ by up to 100% over arid and semi-arid basins and areas with intensive irrigation. Large differences in TWS anomalies from three processing approaches (scaling factor, additive, and multiplicative corrections) were found in arid and semi-arid regions, areas with intensive irrigation, and relatively small basins (e.g., ≤ 200,000 km2). Furthermore, TWS anomaly products from gridded data with CLM4.0 scaling factors and the additive correction approach more closely agree with WGHM output than the multiplicative correction approach. Estimation of groundwater storage changes using GRACE satellites requires caution in selecting an appropriate approach for restoring TWS changes. A priori ground-based data used in forward modeling can provide a powerful tool for explaining the distribution of signal gains or losses caused by low-pass filtering in specific regions of interest and should be very useful for more reliable estimation of groundwater storage changes using GRACE satellites.

  7. Compact rock material gas permeability properties

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Huanling, E-mail: whl_hm@163.com [Key Laboratory of Coastal Disaster and Defence, Ministry of Education, Hohai University, Nanjing 210098 (China); LML, University of Lille, Cite Scientifique, 59655 Villeneuve d’Ascq (France); Xu, Weiya; Zuo, Jing [Institutes of Geotechnical Engineering, Hohai University, Nanjing 210098 (China)

    2014-09-15

    Natural compact rocks, such as sandstone, granite, and rock salt, are the main materials and geological environment for storing underground oil, gas, CO{sub 2,} shale gas, and radioactive waste because they have extremely low permeabilities and high mechanical strengths. Using the inert gas argon as the fluid medium, the stress-dependent permeability and porosity of monzonitic granite and granite gneiss from an underground oil storage depot were measured using a permeability and porosity measurement system. Based on the test results, models for describing the relationships among the permeability, porosity, and confining pressure of rock specimens were analyzed and are discussed. A power law is suggested to describe the relationship between the stress-dependent porosity and permeability; for the monzonitic granite and granite gneiss (for monzonitic granite (A-2), the initial porosity is approximately 4.05%, and the permeability is approximately 10{sup −19} m{sup 2}; for the granite gneiss (B-2), the initial porosity is approximately 7.09%, the permeability is approximately 10{sup −17} m{sup 2}; and the porosity-sensitivity exponents that link porosity and permeability are 0.98 and 3.11, respectively). Compared with moderate-porosity and high-porosity rocks, for which φ > 15%, low-porosity rock permeability has a relatively lower sensitivity to stress, but the porosity is more sensitive to stress, and different types of rocks show similar trends. From the test results, it can be inferred that the test rock specimens’ permeability evolution is related to the relative particle movements and microcrack closure.

  8. Gas and Water Permeability of Concrete

    Energy Technology Data Exchange (ETDEWEB)

    Villar, M. V.; Martin, P. L.; Romero, F. J.; Gutierrez-Rodirgo, V.; Barcala, J. M.

    2012-11-01

    The gas pressure of concrete samples was measured in an unsteady-state equipment working under low injection pressures and in a newly fine tuned steady-state setup working under different pressures. These measurements allowed the estimation of the intrinsic and relative gas permeability of the concrete and of the effect of boundary conditions on them. Permeability decreased with water content, but it was also greatly affected by the hydraulic history of concrete, i.e. if it had been previously dried or wetted. In particular, and for a given degree of saturation, the gas permeability of concrete previously saturated was lower than if the concrete had been just air dried or saturated after air drying. In any case, the gas permeability was about two orders of magnitude higher than the liquid water permeability (10-16 vs. 10-18 m2), probably due to the chemical reactions taking place during saturation (carbonation). The relative gas permeability of concrete increased sharply for water degrees of saturation smaller than 50%. The boundary conditions also affected the gas permeability, which seemed to be mostly conditioned by the back pressure and the confining pressure, increasing as the former increased and decreasing as the latter increased, i.e. decreasing as the effective pressure increased. Overall the increase of pressure head or injection pressure implied a decrease in gas permeability. External,microcracking during air-drying could not be ruled out as responsible for the decrease of permeability with confining pressure. The apparent permeability obtained applying the Klinkenberg method for a given effective pressure was only slightly smaller than the average of all the values measured for the same confining pressure range. For this reason it is considered that the Klinkenberg effect was not relevant in the range of pressures applied. (Author) 37 refs.

  9. Climate and hydrological changes in the northeastern United States: recent trends and implications for forested and aquatic ecosystems

    Science.gov (United States)

    Huntington, Thomas G.; Richardson, Andrew D.; McGuire, Kevin J.; Hayhoe, Katharine

    2009-01-01

    We review twentieth century and projected twenty-first century changes in climatic and hydrologic conditions in the northeastern United States and the implications of these changes for forest ecosystems. Climate warming and increases in precipitation and associated changes in snow and hydrologic regimes have been observed over the last century, with the most pronounced changes occurring since 1970. Trends in specific climatic and hydrologic variables differ in their responses spatially (e.g., coastal vs. inland) and temporally (e.g., spring vs. summer). Trends can differ depending on the period of record analyzed, hinting at the role of decadal-scale climatic variation that is superimposed over the longer-term trend. Model predictions indicate that continued increases in temperature and precipitation across the northeastern United States can be expected over the next century. Ongoing increases in growing season length (earlier spring and later autumn) will most likely increase evapotranspiration and frequency of drought. In turn, an increase in the frequency of drought will likely increase the risk of fire and negatively impact forest productivity, maple syrup production, and the intensity of autumn foliage coloration. Climate and hydrologic changes could have profound effects on forest structure, composition, and ecological functioning in response to the changes discussed here and as described in related articles in this issue of the Journal.

  10. Chinese and Russian Policies on Climate Change: Implications for U.S. National Security Policy

    Science.gov (United States)

    2016-06-01

    crop productivity in China by 2030 as a result of climate change, and a decline of up to 37 percent in rice, maize , and wheat yields after 2050...against global warming. Comparing and contrasting China’s and Russia’s climate change policies and programs may also help to identify gaps in...adequate measures to adapt agriculture to climate change, the annual economic loss from a decrease in climate-determined crop yield in Russia is

  11. The characteristics and interpretability of land surface change and implications for project design

    Science.gov (United States)

    Sohl, Terry L.; Gallant, Alisa L.; Loveland, Thomas R.

    2004-01-01

    The need for comprehensive, accurate information on land-cover change has never been greater. While remotely sensed imagery affords the opportunity to provide information on land-cover change over large geographic expanses at a relatively low cost, the characteristics of land-surface change bring into question the suitability of many commonly used methodologies. Algorithm-based methodologies to detect change generally cannot provide the same level of accuracy as the analyses done by human interpreters. Results from the Land Cover Trends project, a cooperative venture that includes the U.S. Geological Survey, Environmental Protection Agency, and National Aeronautics and Space Administration, have shown that land-cover conversion is a relatively rare event, occurs locally in small patches, varies geographically and temporally, and is spectrally ambiguous. Based on these characteristics of change and the type of information required, manual interpretation was selected as the primary means of detecting change in the Land Cover Trends project. Mixtures of algorithm-based detection and manual interpretation may often prove to be the most feasible and appropriate design for change-detection applications. Serious examination of the expected characteristics and measurability of change must be considered during the design and implementation phase of any change analysis project.

  12. Biodiversity conservation in a changing climate: a review of threats and implications for conservation planning in Myanmar.

    Science.gov (United States)

    Rao, Madhu; Saw Htun; Platt, Steven G; Tizard, Robert; Poole, Colin; Than Myint; Watson, James E M

    2013-11-01

    High levels of species richness and endemism make Myanmar a regional priority for conservation. However, decades of economic and political sanctions have resulted in low conservation investment to effectively tackle threats to biodiversity. Recent sweeping political reforms have placed Myanmar on the fast track to economic development-the expectation is increased economic investments focused on the exploitation of the country's rich, and relatively intact, natural resources. Within a context of weak regulatory capacity and inadequate environmental safeguards, rapid economic development is likely to have far-reaching negative implications for already threatened biodiversity and natural-resource-dependent human communities. Climate change will further exacerbate prevailing threats given Myanmar's high exposure and vulnerability. The aim of this review is to examine the implications of increased economic growth and a changing climate within the larger context of biodiversity conservation in Myanmar. We summarize conservation challenges, assess direct climatological impacts on biodiversity and conclude with recommendations for long-term adaptation approaches for biodiversity conservation.

  13. Greenhouse Gas Implications of Peri-Urban Land Use Change in a Developed City under Four Future Climate Scenarios

    Directory of Open Access Journals (Sweden)

    Alison Rothwell

    2016-12-01

    Full Text Available Present decisions about urbanization of peri-urban (PU areas may contribute to the capacity of cities to mitigate future climate change. Comprehensive mitigative responses to PU development should require integration of urban form and food production to realise potential trade-offs. Despite this, few studies examine greenhouse gas (GHG implications of future urban development combined with impacts on PU food production. In this paper, four future scenarios, at 2050 and 2100 time horizons, were developed to evaluate the potential GHG emissions implications of feeding and housing a growing urban population in Sydney, Australia. The scenarios were thematically downscaled from the four relative concentration pathways. Central to the scenarios were differences in population, technology, energy, housing form, transportation, temperature, food production and land use change (LUC. A life cycle assessment approach was used within the scenarios to evaluate differences in GHG impacts. Differences in GHG emissions between scenarios at the 2100 time horizon, per area of PU land transformed, approximated 0.7 Mt CO2-e per year. Per additional resident this equated to 0.7 to 6.1 t CO2-e per year. Indirect LUC has the potential to be significant. Interventions such as carbon capture and storage technology, renewables and urban form markedly reduced emissions. However, incorporating cross-sectoral energy saving measures within urban planning at the regional scale requires a paradigmatic shift.

  14. The variance of the model representation of nuclear power generation and its implication to the climate change mitigation assessment

    International Nuclear Information System (INIS)

    Wada, Kenichi; Sano, Fuminori; Oshima, Kanji; Akimoto, Keigo

    2013-01-01

    Nuclear power secures affordable carbon-free energy supply, but entails various risks and constraints, such as safety concerns, waste disposal protest campaign, and proliferation. Given the nature of these characteristics of nuclear power generation, there is wide range of variations in representation of nuclear power technologies across models. In this paper, we explore the variance of the model representation of nuclear power generation and its implication to the climate change mitigation assessment, based on the EMF27 study. The most common result is that under efforts to mitigate climate change more nuclear energy use is needed. We find, however, that perspectives on the contribution of nuclear energy to global energy needs vary tremendously among the modeling teams. This diversity mainly comes from the difference in the level of detail that characterize nuclear energy technologies and the broad range of nuclear contributions in the long-term scenarios of global energy use. (author)

  15. Project Summary (2012-2015) – Carbon Dynamics of the Greater Everglades Watershed and Implications of Climate Change

    Energy Technology Data Exchange (ETDEWEB)

    Hinkle, Ross [University of Central Florida; Benscoter, Brian [Florida Atlantic University; Comas, Xavier [Florida Atlantic University; Sumner, David [USGS; DeAngelis, Donald [USGS

    2015-04-07

    Carbon Dynamics of the Greater Everglades Watershed and Implications of Climate Change The objectives of this project are to: 1) quantify above- and below-ground carbon stocks of terrestrial ecosystems along a seasonal hydrologic gradient in the headwaters region of the Greater Everglades watershed; 2) develop budgets of ecosystem gaseous carbon exchange (carbon dioxide and methane) across the seasonal hydrologic gradient; 3) assess the impact of climate drivers on ecosystem carbon exchange in the Greater Everglades headwater region; and 4) integrate research findings with climate-driven terrestrial ecosystem carbon models to examine the potential influence of projected future climate change on regional carbon cycling. Note: this project receives a one-year extension past the original performance period - David Sumner (USGS) is not included in this extension.

  16. Late Quaternary climate-change velocity: Implications for modern distributions and communities

    DEFF Research Database (Denmark)

    Sandel, Brody Steven; Dalsgaard, Bo; Arge, Lars Allan

    a global map of climate-change velocity since the Last Glacial Maximum and used this measure of climate instability to address a number of classic hypotheses. Results/Conclusions We show that historical climate-change velocity is related to a wide range of characteristics of modern distributions...

  17. Establishing a Relationship between Behavior Change Theory and Social Marketing: Implications for Health Education.

    Science.gov (United States)

    Thackeray, Rosemary; Neiger, Brad L.

    2000-01-01

    Describes relationships between behavior change theory and social marketing practice, noting challenges in making behavior change theory an important component of social marketing and proposing that social marketing is the framework to which theory can be applied, creating theory-driven, consumer-focused, more effective health education programs.…

  18. The Changing Health Care Landscape and Implications of Organizational Ethics on Modern Medical Practice

    NARCIS (Netherlands)

    Castlen, Joseph P; Cote, David J; Moojen, Wouter A.; Robe, Pierre A.; Balak, Naci; Brennum, Jannick; Ammirati, Mario; Mathiesen, Tiit; Broekman, Marike L.D.

    2017-01-01

    Introduction Medicine is rapidly changing, both in the level of collective medical knowledge and in how it is being delivered. The increased presence of administrators in hospitals helps to facilitate these changes and ease administrative workloads on physicians; however, tensions sometimes form

  19. Review of the Literature on the Changing Psychological Contract: Implications on Career Management and Organizations

    Science.gov (United States)

    Lessner, Ryan; Akdere, Mesut

    2008-01-01

    The changing psychological contract has become a focus for organizational development, especially as job roles within organizations continue to change. This literature review examines the evolving employee-employer relationship and how this relationship has impacted career management and organizations for over the past century. The paper…

  20. Adapting Choral Singing Experiences for Older Adults: The Implications of Sensory, Perceptual, and Cognitive Changes

    Science.gov (United States)

    Yinger, Olivia Swedberg

    2014-01-01

    As people age, they naturally experience sensory, perceptual, and cognitive changes. Many of these changes necessitate adaptations in designing programs for older adults. Choral singing is an activity that has many potential benefits for older adults, yet the rehearsal environment, presentation style, and content of material presented may need to…

  1. Name Changes in Medically Important Fungi and Their Implications for Clinical Practice

    DEFF Research Database (Denmark)

    de Hoog, G. Sybren; Chaturvedi, Vishnu; Denning, David W.

    2015-01-01

    Recent changes in the Fungal Code of Nomenclature and developments in molecular phylogeny are about to lead to dramatic changes in the naming of medically important molds and yeasts. In this article, we present a widely supported and simple proposal to prevent unnecessary nomenclatural instability....

  2. Regional hydrological impacts of climate change: implications for water management in India

    Directory of Open Access Journals (Sweden)

    A. Mondal

    2015-04-01

    Full Text Available Climate change is most likely to introduce an additional stress to already stressed water systems in developing countries. Climate change is inherently linked with the hydrological cycle and is expected to cause significant alterations in regional water resources systems necessitating measures for adaptation and mitigation. Increasing temperatures, for example, are likely to change precipitation patterns resulting in alterations of regional water availability, evapotranspirative water demand of crops and vegetation, extremes of floods and droughts, and water quality. A comprehensive assessment of regional hydrological impacts of climate change is thus necessary. Global climate model simulations provide future projections of the climate system taking into consideration changes in external forcings, such as atmospheric carbon-dioxide and aerosols, especially those resulting from anthropogenic emissions. However, such simulations are typically run at a coarse scale, and are not equipped to reproduce regional hydrological processes. This paper summarizes recent research on the assessment of climate change impacts on regional hydrology, addressing the scale and physical processes mismatch issues. Particular attention is given to changes in water availability, irrigation demands and water quality. This paper also includes description of the methodologies developed to address uncertainties in the projections resulting from incomplete knowledge about future evolution of the human-induced emissions and from using multiple climate models. Approaches for investigating possible causes of historically observed changes in regional hydrological variables are also discussed. Illustrations of all the above-mentioned methods are provided for Indian regions with a view to specifically aiding water management in India.

  3. The changing structure of the hardwood lumber industry with implications on technology adaptation

    Science.gov (United States)

    William Luppold; John Baumgras; John Baumgras

    2000-01-01

    The hardwood sawmilling industry has been changing over the last 50 years as a result of changes in hardwood sawtimber inventory and in the demand for hardwood lumber. In 1950 the industry was composed of numerous individual mills, few of which produced more than 3 million board feet of lumber annually. During this time the furniture industry was the major user of...

  4. Health risks of climate change: An assessment of uncertainties and its implications for adaption policies

    NARCIS (Netherlands)

    Wardekker, J.A.; de Jong, A.; van Bree, L.; Turkenburg, W.C.; van der Sluijs, J.P.

    2012-01-01

    Background: Projections of health risks of climate change are surrounded with uncertainties in knowledge. Understanding of these uncertainties will help the selection of appropriate adaptation policies. Methods: We made an inventory of conceivable health impacts of climate change, explored the type

  5. Modeling forest mortality caused by drought stress: implications for climate change

    Science.gov (United States)

    Eric J Gustafson; Brian R. Sturtevant

    2013-01-01

    Climate change is expected to affect forest landscape dynamics in many ways, but it is possible that the most important direct impact of climate change will be drought stress. We combined data from weather stations and forest inventory plots (FIA) across the upper Great Lakes region (USA) to study the relationship between measures of drought stress and mortality for...

  6. The Economics of Climate Change in Mexico: Implications for National/Regional Policy

    NARCIS (Netherlands)

    Estrada, E.; Papyrakis, E.; Tol, R.S.J.; Gay-García, C.

    2013-01-01

    The recent Mexican government study, The Economics of Climate Change in Mexico (ECCM), which has largely influenced Mexico's stance on climate change issues and international negotiations, is critically reviewed. Whilst the importance of such government-supported national studies as a first attempt

  7. Name changes in medically important fungi and their implications for clinical practice

    NARCIS (Netherlands)

    de Hoog, G Sybren; Chaturvedi, Vishnu; Denning, David W; Dyer, Paul S; Frisvad, Jens Christian; Geiser, David; Gräser, Yvonne; Guarro, Josep; Haase, Gerhard; Kwon-Chung, Kyung-Joo; Meis, Jacques F; Meyer, Wieland; Pitt, John I; Samson, Robert A; Taylor, John W; Tintelnot, Kathrin; Vitale, Roxana G; Walsh, Thomas J; Lackner, Michaela

    2014-01-01

    Recent changes in the Fungal Code of Nomenclature and developments in molecular phylogeny are about to lead to dramatic changes in the naming of medically important moulds and yeasts. In this article, we present a widely supported and simple proposal to prevent unnecessary nomenclatural instability.

  8. Southern Foresters' Perceptions of Climate Change: Implications for Educational Program Development

    Science.gov (United States)

    Boby, Leslie; Hubbard, William; Megalos, Mark; Morris, Hilary L. C.

    2016-01-01

    An understanding of foresters' perceptions of climate change is important for developing effective educational programs on adaptive forest management. We surveyed 1,398 foresters in the southern United States regarding their perceptions of climate change, observations and concerns about climatic and forest conditions, and knowledge of and interest…

  9. Climate change as an ecosystem architect: implications to rare plant ecology, conservation, and restoration

    Science.gov (United States)

    Constance I. Millar

    2003-01-01

    Recent advances in earth system sciences have revealed significant new information relevant to rare plant ecology and conservation. Analysis of climate change at high resolution with new and precise proxies of paleotemperatures reveals a picture over the past two million years of oscillatory climate change operating simultaneously at multiple timescales. Low-frequency...

  10. The Changing Health Care Landscape and Implications of Organizational Ethics on Modern Medical Practice

    DEFF Research Database (Denmark)

    Castlen, Joseph P; Cote, David J; Moojen, Wouter A

    2017-01-01

    to prevent excessive spending as health care systems become larger and more difficult to manage. Recognizing the cause of changes in health care, which do not always originate with physicians and administrators, along with implementing changes in hospitals such as increased physician leadership, could help...

  11. Climate change and California: potential implications for vegetation, carbon, and fire.

    Science.gov (United States)

    Jonathan. Thompson

    2005-01-01

    Nineteen scientists from leading research institutes in the United States collaborated to estimate how California’s environment and economy would respond to global climate change. A scientist from the PNW Research Station led efforts to estimate effects on vegetation, carbon, and fire.To quantify the range of the possible effects of climate change over the...

  12. Globalization and Organizational Change: Engineers' Experiences and Their Implications for Engineering Education

    Science.gov (United States)

    Lucena, Juan C.

    2006-01-01

    The demand for flexible engineers presents significant challenges to engineering education. Among these is the need for engineers to be prepared to understand and deal with organizational change. Yet engineering education and research on engineers have overlooked the impact of organizational change on engineering work. After outlining the impact…

  13. Epidemiological changes with potential implication for antifungal prescription recommendations for fungaemia

    DEFF Research Database (Denmark)

    Arendrup, M C; Dzajic, Esad; Jensen, R H

    2013-01-01

    Significant changes in the management of fungaemia have occurred over the last decade with increased use of fluconazole prophylaxis, of empirical treatment and of echinocandins as first-line agents for documented disease. These changes may impact the epidemiology of fungaemia. We present nationwide...

  14. The Role of Teacher Emotions in Change: Experiences, Patterns and Implications for Professional Development

    Science.gov (United States)

    Saunders, Rebecca

    2013-01-01

    Research literature in the field of teacher emotions and change broadly accepts that behaviour and cognition are inseparable from perception and emotion. Despite this, educational reform efforts tend to focus predominantly on changing individual behaviours and beliefs and largely neglect or at best pay token attention to the emotional dimensions…

  15. Trends in landscape and vegetation change and implications for the Santa Cruz Watershed

    Science.gov (United States)

    Villarreal, Miguel; Norman, Laura M.; Webb, Robert H.; Turner, Raymond M.

    2013-01-01

    Monitoring and characterizing the interactive effects of land use and climate on land surface processes is a primary focus of land change science, and of particular concern in arid Wells Distribution in Shallow Groundwater Areas Pumping Trends Increase Streamflow Extent Declines 27 environments where both landscapes and livelihoods can be impacted by short-term climate variability. Using a multi-observational approach to land-change analysis that included landownership data as a proxy for land-use practices, multitemporal land-cover maps, and repeat photography dating to the late 19th century, we examine changing spatial and temporal distributions of two vegetation types with high conservation value in the southwestern United States: grasslands and riparian vegetation. Our study area is the bi-national Santa Cruz Watershed, a topographically complex watershed that straddles the Sonoran Desert and the Madrean Archipelago Ecoregions. In this presentation we focus on historical changes in vegetation and land use in grasslands and riparian areas of the Madrean Ecoregion (San Raphael Valley, Cienega Creek, Sonoita), and compare changes in these areas to changes in the warmer and drier Sonoran Ecoregion. Analysis of historical photography confirms major 20th century vegetation shifts documented in other research: woody plant encroachment, desertification of grasslands, and changing riparian and xeroriparian vegetation occurred in both ecoregions following human settlement. However, vegetation changes over the past decade appear to be more subtle and some of the past trajectories appear to be reversing; most notable are recent mesquite declines in xeroriparian and upland areas, and changes from shrubland to grassland area in the Madrean ecoregion. Land cover changes were temporally variable, reflecting broad climate changes. The most dynamic cover changes occurred during the period from 1989 to 1999, a period with two intense droughts. The degree of vegetation change

  16. Nonlinear dynamics in ecosystem response to climatic change: Case studies and policy implications

    Science.gov (United States)

    Burkett, Virginia R.; Wilcox, Douglas A.; Stottlemyer, Robert; Barrow, Wylie; Fagre, Dan; Baron, Jill S.; Price, Jeff; Nielsen, Jennifer L.; Allen, Craig D.; Peterson, David L.; Ruggerone, Greg; Doyle, Thomas

    2005-01-01

    Many biological, hydrological, and geological processes are interactively linked in ecosystems. These ecological phenomena normally vary within bounded ranges, but rapid, nonlinear changes to markedly different conditions can be triggered by even small differences if threshold values are exceeded. Intrinsic and extrinsic ecological thresholds can lead to effects that cascade among systems, precluding accurate modeling and prediction of system response to climate change. Ten case studies from North America illustrate how changes in climate can lead to rapid, threshold-type responses within ecological communities; the case studies also highlight the role of human activities that alter the rate or direction of system response to climate change. Understanding and anticipating nonlinear dynamics are important aspects of adaptation planning since responses of biological resources to changes in the physical climate system are not necessarily proportional and sometimes, as in the case of complex ecological systems, inherently nonlinear.

  17. Quantifying climate change impacts on hydropower generation and implications on electric grid greenhouse gas emissions and operation

    International Nuclear Information System (INIS)

    Tarroja, Brian; AghaKouchak, Amir; Samuelsen, Scott

    2016-01-01

    Here we translate the impacts of climate change on hydropower generation, and discuss implications on greenhouse gas (GHG) emissions and operation in California. We integrate a model of major surface-water reservoirs with an electric grid dispatch model, and perturb it by projected runoff based on representative concentration pathways (RCP4.5 and RCP8.5). Results show that climate change and variability is expected to decrease the average annual hydropower generation by 3.1% under RCP4.5, but have negligible impact under the RCP8.5. Model simulations indicate more inflow, caused by more future extremes, in the future that does not necessarily translate to more energy production because of reservoir spillage of water. While overall volume of future available water for energy production may be similar or higher, the delivery of this volume is expected to be significantly more variable in the future climate than the historical average, which has many implications for hydropower generation. Our results show that the expected changes in future climate leads to increases in grid GHG emissions, load-following capacity, fuel usage, and costs for the RCP4.5 due to generation shortfall, and very slight increases in the same metrics for the RCP8.5 case due to variability causing decreased efficiencies in load-following power plants. - Highlights: • Climate change caused increased overall volume inflow levels to hydropower reservoirs. • Extreme precipitation events caused reservoir spillage and inability to fully use increased inflow. • Hydropower generation decreased for RCP 4.5 and remained similar to historical for RCP 8.5. • Increased climate variability caused decreased efficiencies in load-following power plants.

  18. Long-term environmental and health implications of morphological change and sediment transport with respect to contaminants

    Science.gov (United States)

    Sneddon, Christopher; Copplestone, David; Tyler, Andrew; Hunter, Peter; Smith, Nick

    2014-05-01

    The EPSRC-funded Adaptation and Resilience of Coastal Energy Supply (ARCoES) project encompasses four research strands, involving 14 institutions and six PhD studentships. ARCoES aims to determine the threats posed to future energy generation and the distribution network by flooding and erosion, changing patterns of coastal sedimentation, water temperature and the distribution of plants and animals in the coastal zone. Whilst this research has direct benefits for the operation of coastal power stations, ARCoES aims to have a wider stakeholder engagement through assessing how the resilience of coastal communities may be altered by five hundred years of coastal evolution. Coastal evolution will have substantial implications for the energy sector of the North West of England as former waste storage sites are eroded and remobilised within the intertidal environment. The current intertidal environmental stores of radioactivity will also experience reworking as ocean chemistry changes and saltmarsh chronologies are reworked in response to rising sea levels. There is a duel requirement to understand mass sediment movement along the North West coast of England as understanding the sediment transport dynamics is key to modelling long term coastal change and understanding how the environmental store of radioactivity will be reworked. The University of Stirling is researching the long-term environmental and health implications of remobilisation and transport of contaminated sediments around the UK coastline. Using a synergy of hyperspectral and topographic information the mobilisation of sediment bound contaminants within the coastal environment will be investigated. Potential hazards posed by contaminants are determined by a set of environmental impact test criteria which evaluate the bio-accessibility and ionising dose of contaminants. These test criteria will be used to comment on the likely environmental impact of modelled sediment transport and anticipated changes in

  19. Video Game Addiction and Life Style Changes: Implications for Caregivers Burden.

    Science.gov (United States)

    Sharma, Manoj Kumar

    2016-01-01

    Limitation of available information on caregiver perspective on managing the users excessive use of technology. The present case series explore the caregiver burden related to users addictive use of video game. The users and caregivers approached the service of healthy use of technology (SHUT clinic) for management. They were assessed using Griffith criteria for video game; General Health questionnaire and family burden interview schedule. It demonstrate the addictive use of video game and its impact on users life style and the presence of psychiatric distress/family burden in the caregivers. Caregivers also reported presence of disturbance in psychosocial domains and helplessness to manage the excessive use. It has implications for building support group and service to handle parents' distress and enabling them to handle the dysfunction in users.

  20. Salinity shapes food webs in shallow lakes: implications for increasing aridity with climate change

    DEFF Research Database (Denmark)

    Vidal, Nicolas; Yu, Jinlei; Gutierrez, Maria Florencia

    2015-01-01

    on community and food web structure in 24 lakes along a wide salinity gradient, from freshwater (0.5 g L-1) to hypersaline lakes (115 g L-1), in a semiarid region in North West China. Fish, zooplankton and macroinvertebrate communities were sampled during July 2014 for determination of taxonomy and size......A reduction in runoff and higher evaporation rates are expected to occur towards 2050 in arid and semiarid regions of the world, resulting in a reduction of water level and salinization of inland waters. Besides the natural process of catchment erosion, human activities such as irrigation of crops...... may also increase salinization. Reduced biodiversity in freshwater systems is the most commonly reported effect of salinization, which may have implications for food web structure and likely for ecosystem functioning as well. The objective of the study was to analyze the effects of salinity...

  1. Lung epithelial permeability and inhaled furosemide. Added dimensions in asthmatics

    International Nuclear Information System (INIS)

    Bhure, U.N.; Bhure, S.U.; Bhatt, B.M.; Mistry, S.; Pednekar, S.J.; Chari, V.V.; Desai, S.A.; Joshi, J.M.; Paidhungat, A.J.

    2009-01-01

    Lung clearance rates of inhaled 99m Tc-diethylene-triamine-pentaacetic acid (DTPA) aerosols constitute a sensitive index to evaluate the permeability changes characteristic of airway epithelial damage. It was thought that edema of the airway wall which is reported in asthma could be relieved with a diuretic like furosemide, helping to relieve the symptoms. We intended to study the effect of inhaled furosemide on lung epithelial permeability in asthmatics and smokers with the help of 99m Tc-DTPA lung clearance test (LCT). The study included three groups (n=15), viz. normal healthy controls, asymptomatic chronic smokers, and chronic persistent asthmatics. Each subject underwent the LCT twice, baseline and post-furosemide (Lasix) study, within a week's interval. The post-furosemide study was carried out 15 min after inhalation of 10 mg of lasix. Lung epithelial permeability was determined in terms of clearance half-life (T 1/2 ). The baseline mean T 1/2 values for controls, smokers, and asthmatics were 50.95±16.58, 20.81±5.47, 24.06±6.19 min, respectively. Post-lasix T 1/2 values were 50.83±15.84, 20.70±5.65, 41.27±15.07 min, respectively. There was a significant difference (P<0.001) in baseline and post-lasix clearance values in asthmatics only. Baseline lung epithelial permeability was altered in smokers and asthmatics compared to the controls. Furosemide was effective only in asthmatics in reverting the permeability almost back to the normal range. Inhaled furosemide was effective even in moderate and severe asthmatics. Furosemide has multiple mechanisms of action. It possibly acts at bronchial level in view of the pathology in asthmatics lying in the airways. (author)

  2. The impact of increased food availability on reproduction in a long-distance migratory songbird: implications for environmental change?

    Directory of Open Access Journals (Sweden)

    Adam M Seward

    Full Text Available Many populations of migratory songbirds are declining or shifting in distribution. This is likely due to environmental changes that alter factors such as food availability that may have an impact on survival and/or breeding success. We tested the impact of experimentally supplemented food on the breeding success over three years of northern wheatears (Oenanthe oenanthe, a species in decline over much of Europe. The number of offspring fledged over the season was higher for food-supplemented birds than for control birds. The mechanisms for this effect were that food supplementation advanced breeding date, which, together with increased resources, allowed further breeding attempts. While food supplementation did not increase the clutch size, hatching success or number of chicks fledged per breeding attempt, it did increase chick size in one year of the study. The increased breeding success was greater for males than females; males could attempt to rear simultaneous broods with multiple females as well as attempting second broods, whereas females could only increase their breeding effort via second broods. Multiple brooding is rare in the study population, but this study demonstrates the potential for changes in food availability to affect wheatear breeding productivity, primarily via phenotypic flexibility in the number of breeding attempts. Our results have implications for our understanding of how wheatears may respond to natural changes in food availability due to climate changes or changes in habitat management.

  3. The impact of increased food availability on reproduction in a long-distance migratory songbird: implications for environmental change?

    Science.gov (United States)

    Seward, Adam M; Beale, Colin M; Gilbert, Lucy; Jones, T Hefin; Thomas, Robert J

    2014-01-01

    Many populations of migratory songbirds are declining or shifting in distribution. This is likely due to environmental changes that alter factors such as food availability that may have an impact on survival and/or breeding success. We tested the impact of experimentally supplemented food on the breeding success over three years of northern wheatears (Oenanthe oenanthe), a species in decline over much of Europe. The number of offspring fledged over the season was higher for food-supplemented birds than for control birds. The mechanisms for this effect were that food supplementation advanced breeding date, which, together with increased resources, allowed further breeding attempts. While food supplementation did not increase the clutch size, hatching success or number of chicks fledged per breeding attempt, it did increase chick size in one year of the study. The increased breeding success was greater for males than females; males could attempt to rear simultaneous broods with multiple females as well as attempting second broods, whereas females could only increase their breeding effort via second broods. Multiple brooding is rare in the study population, but this study demonstrates the potential for changes in food availability to affect wheatear breeding productivity, primarily via phenotypic flexibility in the number of breeding attempts. Our results have implications for our understanding of how wheatears may respond to natural changes in food availability due to climate changes or changes in habitat management.

  4. Regulative change targeting energy performance of buildings in Sweden. Key drivers and main implications

    Energy Technology Data Exchange (ETDEWEB)

    Fuglseth, Bente Beckstroem

    2009-02-15

    This report has explored changes in two regulations targeting energy performance of buildings in Sweden, energy requirements and certification of buildings. The objective has been to investigate the effect of the implementation of the EU directive on energy performance of buildings (EPBD) on these two regulations and to what degree the directive can explain the regulative changes. The analytical framework has also included domestic factors; the influence of the national government and the organizational field. The analysis revealed that whereas the EPBD has acted only as facilitator in connection with the changes in energy requirements, it has been the sole driver of some of the changes in Sweden's new certification system. Several of the changes during the period studied can however be traced to the national government and the organizational field. But the EPBD has also worked as a facilitator of the changes promoted by domestic actors. The directive has been used to legitimize radical changes that would have been difficult to implement in other ways. (Author). 40 refs., 2 tabs

  5. Vegetation response to climate change : implications for Canada's conservation lands

    Energy Technology Data Exchange (ETDEWEB)

    Scott, D. [Environment Canada, Ottawa, ON (Canada). Adaptation and Impact Research Group; Lemieux, C. [Waterloo Univ., ON (Canada). Dept. of Geography

    2003-05-01

    Studies have shown that Canada's national parks are vulnerable to the impacts of climate change. A wide range of biophysical climate change impacts could affect the integrity of conservation lands in each region of Canada. This report examines the potential impact of climate change on landscape alterations and vegetation distribution in Canada's wide network of conservation lands. It also presents several ways to integrate climate change into existing conservation policy and adaptation strategies. Canada's conservation lands include provincial parks, migratory bird sanctuaries, national wildlife areas and wildlife protected areas. This is the first study to examine biome changes by applying an equilibrium Global Vegetation Model (GVM) to Canada's network of national park systems. Some of the policy and planning challenges posed by changes in landscape level vegetation were also addressed. The report indicates that in terms of potential changes to the biome classification of Canada's national forests, more northern biomes are projected to decrease. These northern biomes include the tundra, taiga and boreal conifer forests. 56 refs., 8 tabs., 6 figs.

  6. Global climate change implications for coastal and offshore oil and gas development

    International Nuclear Information System (INIS)

    Burkett, Virginia

    2011-01-01

    The discussion and debate about climate change and oil and gas resource development has generally focused on how fossil fuel use affects the Earth's climate. This paper explores how the changing climate is likely to affect oil and gas operations in low-lying coastal areas and the outer continental shelf. Oil and gas production in these regions comprises a large sector of the economies of many energy producing nations. Six key climate change drivers in coastal and marine regions are characterized with respect to oil and gas development: changes in carbon dioxide levels and ocean acidity, air and water temperature, precipitation patterns, the rate of sea level rise, storm intensity, and wave regime. These key drivers have the potential to independently and cumulatively affect coastal and offshore oil and gas exploration, production, and transportation, and several impacts of climate change have already been observed in North America. - Highlights: ► Climate change effects on coastal and offshore energy development have been observed in some regions. ► Key drivers include changes in temperature, precipitation, sea level rise, storm intensity and wave regime. ► These can independently and cumulatively affect coastal and offshore exploration, production, and transportation. ► A methodical vulnerability and impact assessment is needed to support adaptation in this sector of the global economy.

  7. Implications of climate change scenarios for soil erosion potential in the USA

    Energy Technology Data Exchange (ETDEWEB)

    Phillips, D L; White, D; Johnson, B [US EPA, Corvallis, OR (United States). Environmental Research Laboratory

    1993-07-01

    Atmospheric general circulation models (GCMs) project that increasing atmospheric concentrations of greenhouse gases may result in global changes in temperature and precipitation over the next 40-100 years. Equilibrium climate scenarios from four GCMs run under doubled CO[sub 2] conditions were examined for their effect on the climatic potential for sheet and rill erosion in the conterminous USA. Changes in the mean annual rainfall factor (R) in the Universal Soil Loss Equation (USLE) were calculated for each cropland, pastureland and rangeland sample point in the 1987 National Resources Inventory. Projected annual precipitation changes were assumed to be from differences in either storm frequency or storm intensity. With all other USLE factors held constant these changes in R translated to changes in the sheet and rill erosion national average of +2 to +16 per cent in croplands, -2 to +10 per cent in pasturelands and 5 to +22 per cent in rangelands under the eight scenarios. Land with erosion rates above the soil loss tolerance (T) level and land classified as highly erodible also increased slightly. These results show the range of sensitivity of soil erosion potential by water under projected climate change scenarios. However, actual changes in soil erosion could be mitigated by management practices, or possibly by increased crop growth and residue production under higher atmospheric CO[sub 2] concentrations.

  8. Climate change drives a shift in peatland ecosystem plant community: implications for ecosystem function and stability.

    Science.gov (United States)

    Dieleman, Catherine M; Branfireun, Brian A; McLaughlin, James W; Lindo, Zoë

    2015-01-01

    The composition of a peatland plant community has considerable effect on a range of ecosystem functions. Peatland plant community structure is predicted to change under future climate change, making the quantification of the direction and magnitude of this change a research priority. We subjected intact, replicated vegetated poor fen peat monoliths to elevated temperatures, increased atmospheric carbon dioxide (CO2 ), and two water table levels in a factorial design to determine the individual and synergistic effects of climate change factors on the poor fen plant community composition. We identify three indicators of a regime shift occurring in our experimental poor fen system under climate change: nonlinear decline of Sphagnum at temperatures 8 °C above ambient conditions, concomitant increases in Carex spp. at temperatures 4 °C above ambient conditions suggesting a weakening of Sphagnum feedbacks on peat accumulation, and increased variance of the plant community composition and pore water pH through time. A temperature increase of +4 °C appeared to be a threshold for increased vascular plant abundance; however the magnitude of change was species dependent. Elevated temperature combined with elevated CO2 had a synergistic effect on large graminoid species abundance, with a 15 times increase as compared to control conditions. Community analyses suggested that the balance between dominant plant species was tipped from Sphagnum to a graminoid-dominated system by the combination of climate change factors. Our findings indicate that changes in peatland plant community composition are likely under future climate change conditions, with a demonstrated shift toward a dominance of graminoid species in poor fens. © 2014 John Wiley & Sons Ltd.

  9. Impacts and managerial implications for sewer systems due to recent changes to inputs in domestic wastewater - A review.

    Science.gov (United States)

    Mattsson, Jonathan; Hedström, Annelie; Ashley, Richard M; Viklander, Maria

    2015-09-15

    Ever since the advent of major sewer construction in the 1850s, the issue of increased solids deposition in sewers due to changes in domestic wastewater inputs has been frequently debated. Three recent changes considered here are the introduction of kitchen sink food waste disposers (FWDs); rising levels of inputs of fat, oil and grease (FOG); and the installation of low-flush toilets (LFTs). In this review these changes have been examined with regard to potential solids depositional impacts on sewer systems and the managerial implications. The review indicates that each of the changes has the potential to cause an increase in solids deposition in sewers and this is likely to be more pronounced for the upstream reaches of networks that serve fewer households than the downstream parts and for specific sewer features such as sags. The review has highlighted the importance of educational campaigns directed to the public to mitigate deposition as many of the observed problems have been linked to domestic behaviour in regard to FOGs, FWDs and toilet flushing. A standardized monitoring procedure of repeat sewer blockage locations can also be a means to identify depositional hot-spots. Interactions between the various changes in inputs in the studies reviewed here indicated an increased potential for blockage formation, but this would need to be further substantiated. As the precise nature of these changes in inputs have been found to be variable, depending on lifestyles and type of installation, the additional problems that may arise pose particular challenges to sewer operators and managers because of the difficulty in generalizing the nature of the changes, particularly where retrofitting projects in households are being considered. The three types of changes to inputs reviewed here highlight the need to consider whether or not more or less solid waste from households should be diverted into sewers. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Modeling the prospects for climatic change: current state-of-the-art and implications

    Energy Technology Data Exchange (ETDEWEB)

    Kellogg, W. M.

    1980-04-04

    It has been increasingly suggested that the world's climate is going to change in the next several decades, primarily as a result of anthropogenic perturbations to the global carbon cycle brought about by fossil fuel burning and large-scale deforestation. In order to cope with these future climatic changes, it is necessary that tools be developed to predict how complex systems respond to a given change of conditions. This report summarizes the status of our ability to model the planetary system that determines the climate. (ACR)

  11. Permeability Measurements of Rock Samples from Conduit Drilling at Unzen Volcano, Japan

    Science.gov (United States)

    Watanabe, T.; Shimizu, Y.; Noguchi, S.; Nakada, S.

    2006-12-01

    (conduit samples) decreases by around one order of magnitude as the confining pressure increases from the atmospheric pressure to 50 MPa. The pressure dependence sensitively reflects the geometry of pores that control the interconnection of pores. Implications for degassing processes will be discussed on the basis of measured permeability and SEM images.

  12. Climate change and global warming: implications for sub-Saharan Africa

    Energy Technology Data Exchange (ETDEWEB)

    Christian, E.

    2010-07-01

    The study reviews the potential threats of climate change in sub-Sahara Africa. It paints a picture of how the major green house gases (GHGs) -- CO{sub 2}, CH{sub 4} -- will grow in the sub-continent before the year 2015. The study also highlights the potential causes of climate change in the sub-continent based on anthropogenic and physical factors. It further examined the impacts of climate change in the sub-region based on the sensitivity, vulnerability and adaptations opened to the sub-region. Observation shows that overall social and economic activities in sub-Sahara Africa will be substantially worse than in any other developing world. Consequently, mitigation and adaptation measures were suggested to alleviate the impacts of climate change in the sub-region.

  13. Uncertainty in the response of transpiration to CO2 and implications for climate change

    International Nuclear Information System (INIS)

    Mengis, N; Keller, D P; Oschlies, A; Eby, M

    2015-01-01

    While terrestrial precipitation is a societally highly relevant climate variable, there is little consensus among climate models about its projected 21st century changes. An important source of precipitable water over land is plant transpiration. Plants control transpiration by opening and closing their stomata. The sensitivity of this process to increasing CO 2 concentrations is uncertain. To assess the impact of this uncertainty on future climate, we perform experiments with an intermediate complexity Earth System Climate Model (UVic ESCM) for a range of model-imposed transpiration-sensitivities to CO 2 . Changing the sensitivity of transpiration to CO 2 causes simulated terrestrial precipitation to change by −10% to +27% by 2100 under a high emission scenario. This study emphasises the importance of an improved assessment of the dynamics of environmental impact on vegetation to better predict future changes of the terrestrial hydrological and carbon cycles. (letter)

  14. Chronic disease and climate change: understanding co-benefits and their policy implications.

    Science.gov (United States)

    Capon, Anthony G; Rissel, Chris E

    2010-01-01

    Chronic disease and climate change are major public policy challenges facing governments around the world. An improved understanding of the relationship between chronic disease and climate change should enable improved policy formulation to support both human health and the health of the planet. Chronic disease and climate change are both unintended consequences of our way of life, and are attributable in part to the ready availability of inexpensive fossil fuel energy. There are co-benefits for health from actions to address climate change. For example, substituting physical activity and a vegetable-rich diet for motor vehicle transport and a meat-rich diet is both good for health and good for the planet. We should encourage ways of living that use less carbon as these can be healthy ways of living, for both individuals and society. Quantitative modelling of co-benefits should inform policy responses.

  15. Regeneration and abnormality in benthic foraminifer Rosalina leei: Implications in reconstructing past salinity changes

    Digital Repository Service at National Institute of Oceanography (India)

    Kurtarkar, S.R.; Nigam, R.; Saraswat, R.; Linshy, V.N.

    water, especially in regions where rivers meet the ocean. Benthic foraminifera, preferentially marine microorganisms with a hard calcareous or agglutinated exoskeleton known as the test, are one of the most abundant groups of microorganisms... temperature under incubators and under 12 hour light -12 hour dark condition throughout the experiment. In order to avoid evaporation, culture trays were wrapped in thin polythene film, immediately after changing the culture media. Culture media was changed...

  16. Regional Distribution Shifts Help Explain Local Changes in Wintering Raptor Abundance: Implications for Interpreting Population Trends

    Science.gov (United States)

    Paprocki, Neil; Heath, Julie A.; Novak, Stephen J.

    2014-01-01

    Studies of multiple taxa across broad-scales suggest that species distributions are shifting poleward in response to global climate change. Recognizing the influence of distribution shifts on population indices will be an important part of interpreting trends within management units because current practice often assumes that changes in local populations reflect local habitat conditions. However, the individual- and population-level processes that drive distribution shifts may occur across a large, regional scale and have little to do with the habitats within the management unit. We examined the latitudinal center of abundance for the winter distributions of six western North America raptor species using Christmas Bird Counts from 1975–2011. Also, we considered whether population indices within western North America Bird Conservation Regions (BCRs) were explained by distribution shifts. All six raptors had significant poleward shifts in their wintering distributions over time. Rough-legged Hawks (Buteo lagopus) and Golden Eagles (Aquila chrysaetos) showed the fastest rate of change, with 8.41 km yr−1 and 7.74 km yr−1 shifts, respectively. Raptors may be particularly responsive to warming winters because of variable migration tendencies, intraspecific competition for nesting sites that drives males to winter farther north, or both. Overall, 40% of BCR population trend models were improved by incorporating information about wintering distributions; however, support for the effect of distribution on BCR indices varied by species with Rough-legged Hawks showing the most evidence. These results emphasize the importance of understanding how regional distribution shifts influence local-scale population indices. If global climate change is altering distribution patterns, then trends within some management units may not reflect changes in local habitat conditions. The methods used to monitor and manage bird populations within local BCRs will fundamentally change as

  17. Changes in the measurement of fair value : implications for accounting earnings.

    OpenAIRE

    Fargher, N.; Zhang, J.

    2014-01-01

    With the FASB's issue of staff position papers in 2009 and the relaxation of how fair value standards are applied, there has been a change in the practice of how fair value is measured. Since the FASB staff position papers in 2009, fair value measurement by financial institutions has increasingly relied on managerial assumptions. This study examines the impact of this change on the quality of earnings. Consistent with attribute substitution theory that emphasises reliability over relevance, w...

  18. Climate change impacts on coral reefs: synergies with local effects, possibilities for acclimation, and management implications.

    Science.gov (United States)

    Ateweberhan, Mebrahtu; Feary, David A; Keshavmurthy, Shashank; Chen, Allen; Schleyer, Michael H; Sheppard, Charles R C

    2013-09-30

    Most reviews concerning the impact of climate change on coral reefs discuss independent effects of warming or ocean acidification. However, the interactions between these, and between these and direct local stressors are less well addressed. This review underlines that coral bleaching, acidification, and diseases are expected to interact synergistically, and will negatively influence survival, growth, reproduction, larval development, settlement, and post-settlement development of corals. Interactions with local stress factors such as pollution, sedimentation, and overfishing are further expected to compound effects of climate change. Reduced coral cover and species composition following coral bleaching events affect coral reef fish community structure, with variable outcomes depending on their habitat dependence and trophic specialisation. Ocean acidification itself impacts fish mainly indirectly through disruption of predation- and habitat-associated behavior changes. Zooxanthellate octocorals on reefs are often overlooked but are substantial occupiers of space; these also are highly susceptible to bleaching but because they tend to be more heterotrophic, climate change impacts mainly manifest in terms of changes in species composition and population structure. Non-calcifying macroalgae are expected to respond positively to ocean acidification and promote microbe-induced coral mortality via the release of dissolved compounds, thus intensifying phase-shifts from coral to macroalgal domination. Adaptation of corals to these consequences of CO2 rise through increased tolerance of corals and successful mutualistic associations between corals and zooxanthellae is likely to be insufficient to match the rate and frequency of the projected changes. Impacts are interactive and magnified, and because there is a limited capacity for corals to adapt to climate change, global targets of carbon emission reductions are insufficient for coral reefs, so lower targets should be

  19. Technological, political and economic changes and their implications for the evolution of broadcasting services

    DEFF Research Database (Denmark)

    Tadayoni, Reza

    2000-01-01

    The subject of this Ph.D. thesis is changes in the market for broadcasting services as a result of technological, political, and economic drivers. Broadcasting services can be categorised as a part of the ICT-based information and knowledge intensive services that have gone through radical changes...... and demand sites, scarcity of transmission resources, and the historical aspects that make the development of the broadcasting service market different from other information and knowledge intensive services....

  20. Vulnerability of solar energy infrastructure and output to extreme events: Climate change implications (Conference paper)

    OpenAIRE

    Patt, A.; Pfenninger, S.; Lilliestam, J.

    2010-01-01

    This paper explores the potential vulnerability of solar energy systems to future extreme event risks as a consequence of climate change. We describe the three main technologies likely to be used to harness sunlight -- thermal heating, photovoltaic (PV), and concentrating solar power (CSP) -- and identify critical extreme event vulnerabilities for each one. We then compare these vulnerabilities with assessments of future changes in extreme event risk levels. We do not identify any vulnerabili...

  1. Economic and labour market implications of climate change on the tourism sector of the Maltese Islands

    OpenAIRE

    Jones, Andrew;

    2015-01-01

    This paper reviews threats to, and consequences of, current climate and environmental change on tourism destinations. The paper reviews recent published research on the impacts of climate and environmental change and consequences of such on the physical social and economic character of tourism operations using the Maltese Islands as a case. The validity and practicality of management options to tackle the complex nature and juxtaposition between tourism growth, climate...

  2. Regional Distribution Shifts Help Explain Local Changes in Wintering Raptor Abundance: Implications for Interpreting Population Trends

    OpenAIRE

    Paprocki, Neil; Heath, Julie A.; Novak, Stephen J.

    2014-01-01

    Studies of multiple taxa across broad-scales suggest that species distributions are shifting poleward in response to global climate change. Recognizing the influence of distribution shifts on population indices will be an important part of interpreting trends within management units because current practice often assumes that changes in local populations reflect local habitat conditions. However, the individual- and population-level processes that drive distribution shifts may occur across a ...

  3. Regional distribution shifts help explain local changes in wintering raptor abundance: implications for interpreting population trends.

    Directory of Open Access Journals (Sweden)

    Neil Paprocki

    Full Text Available Studies of multiple taxa across broad-scales suggest that species distributions are shifting poleward in response to global climate change. Recognizing the influence of distribution shifts on population indices will be an important part of interpreting trends within management units because current practice often assumes that changes in local populations reflect local habitat conditions. However, the individual- and population-level processes that drive distribution shifts may occur across a large, regional scale and have little to do with the habitats within the management unit. We examined the latitudinal center of abundance for the winter distributions of six western North America raptor species using Christmas Bird Counts from 1975-2011. Also, we considered whether population indices within western North America Bird Conservation Regions (BCRs were explained by distribution shifts. All six raptors had significant poleward shifts in their wintering distributions over time. Rough-legged Hawks (Buteo lagopus and Golden Eagles (Aquila chrysaetos showed the fastest rate of change, with 8.41 km yr(-1 and 7.74 km yr(-1 shifts, respectively. Raptors may be particularly responsive to warming winters because of variable migration tendencies, intraspecific competition for nesting sites that drives males to winter farther north, or both. Overall, 40% of BCR population trend models were improved by incorporating information about wintering distributions; however, support for the effect of distribution on BCR indices varied by species with Rough-legged Hawks showing the most evidence. These results emphasize the importance of understanding how regional distribution shifts influence local-scale population indices. If global climate change is altering distribution patterns, then trends within some management units may not reflect changes in local habitat conditions. The methods used to monitor and manage bird populations within local BCRs will fundamentally

  4. Climate Change Mitigation: Climate, Health, and Equity Implications of the Visible and the Hidden

    OpenAIRE

    Shonkoff, Seth Berrin

    2012-01-01

    Anthropogenic climate change and the mitigation strategies aimed to attenuate it are both issues of great importance for human rights, public health, and socioeconomic equity. To understand these concerns and to better inform policy and strategic action it is critical to explore: 1) the disparities in the costs and benefits of climate shifts; 2) the abilities of different populations to adapt to these shifts; and 3) the social and health equity dimensions of the climate change mitigation stra...

  5. The Effects of Weather on Oilseed Rape (OSR) Yield in China: Future Implications of Climate Change

    OpenAIRE

    Yaqin He; Brian J. Revell; Bofeng Leng; Zhongchao Feng

    2017-01-01

    Understanding the role of climatic factors on crop yields is essential in predicting the future impact of climate change. In order to understand the influence of climatic factors on OSR, detailed farm-level panel data from 2566 farms across 67 counties of the 6 major OSR production regions in China, from the surveys conducted by the national OSR industry project between 2008 and 2013, were used to examine the contribution of changes in selected climatic variables between 2008 and 2013 to yiel...

  6. Implication of climate change for the persistence of raptors in arid savanna

    Energy Technology Data Exchange (ETDEWEB)

    Wichmann, M.C.; Wissel, C. [UFZ-Center for Environmental Research, Dept. of Ecological Modelling, Leipzig (Germany); Jeltsch, F. [Univ. of Potsdam, Inst. for Biochemistry and Biology, Potsdam (Germany); Dean, W.R.J. [Univ. of Cape Town, Percy FitzPatrick Inst. of African Ornithology, Rondebosch (South Africa); Moloney, K.A. [Iowa State Univ., Dept. of Botany, Ames, IA (United States)

    2003-07-01

    Arid savannas are regarded as one of the ecosystems most likely to be affected by climate change. In these dry conditions, even top predators like raptors are affected by water availability and precipitation. However, few research initiatives have a adressed the question of how climate change will affect population dynamics and extinction risk of particular species in and ecosystems. Here, we use an individual-oriented modeling approach to conduct experiments on the population dynamics of long lived raptors. We investigate the potential impact of precipitation variation caused by climate change on raptors in and savanna using the tawny eagle (Aquila rapax) in the southern Kalahari as a case study. We simulated various modifications of precipitation scenarios predicted for climate change, such as lowered annual precipitation mean, increased inter-annual variation and increased auto-correlation in precipitation. We found a high impact of these modifications on extinction risk of tawny eagles, with reduced population persistence in most cases. Decreased mean annual precipitation and increased inter-annual variation both caused dramatic decreases in population persistence. Increased autocorrelation in precipitation led only to slightly accelerated extinction of simulated populations. Finally. for various patterns of periodically fluctuating precipitation, we found both increased and decreased population persistence. In summary, our results suggest that the impacts on raptor population dynamics and survival caused by climate change in and savannas will be great. We emphasize that even if under climate change the mean annual precipitation remains constant but the inter-annual variation increases the persistence of raptor populations in and savannas will decrease considerably. This suggests a new dimension, of climate change driven impacts on population persistence and consequently on biodiversity. However, more investigations on particular species and/or species groups

  7. Climate Change and Developing-Country Cities: Implications For Environmental Health and Equity

    OpenAIRE

    Campbell-Lendrum, Diarmid; Corvalán, Carlos

    2007-01-01

    Climate change is an emerging threat to global public health. It is also highly inequitable, as the greatest risks are to the poorest populations, who have contributed least to greenhouse gas (GHG) emissions. The rapid economic development and the concurrent urbanization of poorer countries mean that developing-country cities will be both vulnerable to health hazards from climate change and, simultaneously, an increasing contributor to the problem. We review the specific health vulnerabilitie...

  8. Changes in ice cover thickness and lake level of Lake Hoare, Antarctica - Implications for local climatic change

    Science.gov (United States)

    Wharton, Robert A., Jr.; Mckay, Christopher P.; Clow, Gary D.; Andersen, Dale T.; Simmons, George M., Jr.; Love, F. G.

    1992-01-01

    Results are reported from 10 years of ice-thickness measurements at perennially ice-covered Lake Hoare in southern Victoria Land, Antarctica. The ice cover of this lake had been thinning steadily at a rate exceeding 20 cm/yr during the last decade but seems to have recently stabilized at a thickness of 3.3 m. Data concerning lake level and degree-days above freezing are presented to show the relationship between peak summer temperatures and the volume of glacier-derived meltwater entering Lake Hoare each summer. From these latter data it is inferred that peak summer temperatures have been above 0 C for a progressively longer period of time each year since 1972. Possible explanations for the thinning of the lake ice are considered. The thickness of the ice cover is determined by the balance between freezing during the winter and ablation that occurs all year but maximizes in summer. It is suggested that the term most likely responsible for the change in the ice cover thickness at Lake Hoare is the extent of summer melting, consistent with the rising lake levels.

  9. Public attitudes to climate change and carbon mitigation—Implications for energy-associated behaviours

    International Nuclear Information System (INIS)

    Borgstede, Chris von; Andersson, Maria; Johnsson, Filip

    2013-01-01

    This work explores public opinions regarding climate change and mitigation options and examines how psychological factors, such as attitudes, norms, and willingness to pay, determine self-reported energy-efficient behaviour. The aim is to create knowledge for the design and implementation of policy measures. The results of an opinion poll conducted in 2005 and 2010 are compared. The number of respondents favouring new technologies as a way to reduce emissions was substantially lower in 2010 than in 2005, whereas there was an increase in the number of people who acknowledged that lifestyle changes are necessary to counteract climate changes. This indicates an increased awareness among the public of the need for lifestyle changes, which could facilitate implementation of policies promoting environmental behaviour. Renewable energy and energy saving measures were ranked as the top two measures for mitigating climate change in both polls. In determining which energy behaviours of the public are determined by psychological factors, an analysis of the 2010 survey revealed that respondents with pro-environmental attitudes towards global warming favour significantly increased use of renewable energy technologies and greater engagement in energy-efficient behaviours. - Highlights: ► Public opinion place priority to environmental issues and beliefs to change current lifestyle. ► A decline in favoring new technologies as a way to reduce emissions in 2010 compare to 2005 poll. ► Environmental attitudes relate to favor of renewable energy technologies. ► Environmental attitudes relate to households energy efficient behaviour

  10. Modelling plant invasion pathways in protected areas under climate change: implication for invasion management

    Directory of Open Access Journals (Sweden)

    C.-J. Wang

    2017-12-01

    Full Text Available Global climate change may enable invasive plant species (IPS to invade protected areas (PAs, but plant invasion on a global scale has not yet been explicitly addressed. Here, we mapped the potential invasion pathways for IPS in PAs across the globe and explored potential factors determining the pathways of plant invasion under climate change. We used species distribution modelling to estimate the suitable habitats of 386 IPS and applied a corridor analysis to compute the potential pathways of IPS in PAs under climate change. Subsequently, we analysed the potential factors affecting the pathways in PAs. According to our results, the main potential pathways of IPS in PAs are in Europe, eastern Australia, New Zealand, southern Africa, and eastern regions of South America and are strongly influenced by changes in temperature and precipitation. Protected areas can play an important role in preventing and controlling the spread of IPS under climate change. This is due to the fact that measures are taken to monitor climate change in detail, to provide effective management near or inside PAs, and to control the introduction of IPS with a high capacity for natural dispersal. A review of conservation policies in PAs is urgently needed.

  11. Implications of climate change for wetland-dependent birds in the Prairie Pothole Region

    Science.gov (United States)

    Steen, Valerie; Skagen, Susan K.; Melcher, Cynthia P.

    2016-01-01

    The habitats and food resources required to support breeding and migrant birds dependent on North American prairie wetlands are threatened by impending climate change. The North American Prairie Pothole Region (PPR) hosts nearly 120 species of wetland-dependent birds representing 21 families. Strategic management requires knowledge of avian habitat requirements and assessment of species most vulnerable to future threats. We applied bioclimatic species distribution models (SDMs) to project range changes of 29 wetland-dependent bird species using ensemble modeling techniques, a large number of General Circulation Models (GCMs), and hydrological climate covariates. For the U.S. PPR, mean projected range change, expressed as a proportion of currently occupied range, was −0.31 (± 0.22 SD; range − 0.75 to 0.16), and all but two species were projected to lose habitat. Species associated with deeper water were expected to experience smaller negative impacts of climate change. The magnitude of climate change impacts was somewhat lower in this study than earlier efforts most likely due to use of different focal species, varying methodologies, different modeling decisions, or alternative GCMs. Quantification of the projected species-specific impacts of climate change using species distribution modeling offers valuable information for vulnerability assessments within the conservation planning process.

  12. Metacognitive monitoring and control in visual change detection: Implications for situation awareness and cognitive control

    Science.gov (United States)

    McAnally, Ken I.; Morris, Adam P.; Best, Christopher

    2017-01-01

    Metacognitive monitoring and control of situation awareness (SA) are important for a range of safety-critical roles (e.g., air traffic control, military command and control). We examined the factors affecting these processes using a visual change detection task that included representative tactical displays. SA was assessed by asking novice observers to detect changes to a tactical display. Metacognitive monitoring was assessed by asking observers to estimate the probability that they would correctly detect a change, either after study of the display and before the change (judgement of learning; JOL) or after the change and detection response (judgement of performance; JOP). In Experiment 1, observers failed to detect some changes to the display, indicating imperfect SA, but JOPs were reasonably well calibrated to objective performance. Experiment 2 examined JOLs and JOPs in two task contexts: with study-time limits imposed by the task or with self-pacing to meet specified performance targets. JOPs were well calibrated in both conditions as were JOLs for high performance targets. In summary, observers had limited SA, but good insight about their performance and learning for high performance targets and allocated study time appropriately. PMID:28915244

  13. Evidence and implications of recent climate change in Northern Alaska and other Arctic regions

    Science.gov (United States)

    Hinzman, L.D.; Bettez, N.D.; Bolton, W.R.; Chapin, F.S.; Dyurgerov, M.B.; Fastie, C.L.; Griffith, B.; Hollister, R.D.; Hope, A.; Huntington, H.P.; Jensen, A.M.; Jia, G.J.; Jorgenson, T.; Kane, D.L.; Klein, D.R.; Kofinas, G.; Lynch, A.H.; Lloyd, A.H.; McGuire, A.D.; Nelson, Frederick E.; Oechel, W.C.; Osterkamp, T.E.; Racine, C.H.; Romanovsky, V.E.; Stone, R.S.; Stow, D.A.; Sturm, M.; Tweedie, C.E.; Vourlitis, G.L.; Walker, M.D.; Walker, D.A.; Webber, P.J.; Welker, J.M.; Winker, K.S.; Yoshikawa, K.

    2005-01-01

    The Arctic climate is changing. Permafrost is warming, hydrological processes are changing and biological and social systems are also evolving in response to these changing conditions. Knowing how the structure and function of arctic terrestrial ecosystems are responding to recent and persistent climate change is paramount to understanding the future state of the Earth system and how humans will need to adapt. Our holistic review presents a broad array of evidence that illustrates convincingly; the Arctic is undergoing a system-wide response to an altered climatic state. New extreme and seasonal surface climatic conditions are being experienced, a range of biophysical states and processes influenced by the threshold and phase change of freezing point are being altered, hydrological and biogeochemical cycles are shifting, and more regularly human sub-systems are being affected. Importantly, the patterns, magnitude and mechanisms of change have sometimes been unpredictable or difficult to isolate due to compounding factors. In almost every discipline represented, we show how the biocomplexity of the Arctic system has highlighted and challenged a paucity of integrated scientific knowledge, the lack of sustained observational and experimental time series, and the technical and logistic constraints of researching the Arctic environment. This study supports ongoing efforts to strengthen the interdisciplinarity of arctic system science and improve the coupling of large scale experimental manipulation with sustained time series observations by incorporating and integrating novel technologies, remote sensing and modeling. ?? Springer 2005.

  14. Implications of climate change for agricultural productivity in the early twenty-first century.

    Science.gov (United States)

    Gornall, Jemma; Betts, Richard; Burke, Eleanor; Clark, Robin; Camp, Joanne; Willett, Kate; Wiltshire, Andrew

    2010-09-27

    This paper reviews recent literature concerning a wide range of processes through which climate change could potentially impact global-scale agricultural productivity, and presents projections of changes in relevant meteorological, hydrological and plant physiological quantities from a climate model ensemble to illustrate key areas of uncertainty. Few global-scale assessments have been carried out, and these are limited in their ability to capture the uncertainty in climate projections, and omit potentially important aspects such as extreme events and changes in pests and diseases. There is a lack of clarity on how climate change impacts on drought are best quantified from an agricultural perspective, with different metrics giving very different impressions of future risk. The dependence of some regional agriculture on remote rainfall, snowmelt and glaciers adds to the complexity. Indirect impacts via sea-level rise, storms and diseases have not been quantified. Perhaps most seriously, there is high uncertainty in the extent to which the direct effects of CO(2) rise on plant physiology will interact with climate change in affecting productivity. At present, the aggregate impacts of climate change on global-scale agricultural productivity cannot be reliably quantified.

  15. Predicting pan-tropical climate change induced forest stock gains and losses-implications for REDD

    International Nuclear Information System (INIS)

    Gumpenberger, Marlies; Vohland, Katrin; Heyder, Ursula; Poulter, Benjamin; Rammig, Anja; Popp, Alexander; Cramer, Wolfgang; Macey, Kirsten

    2010-01-01

    Deforestation is a major threat to tropical forests worldwide, contributing up to one-fifth of global carbon emissions into the atmosphere. Despite protection efforts, deforestation of tropical forests has continued in recent years. Providing incentives to reducing deforestation has been proposed in the United Nations Framework Convention on Climate Change (UNFCCC) Bali negotiations in 2007 to decelerate emissions from deforestation (REDD-reduced emissions from deforestation and forest degradation). A number of methodological issues such as ensuring permanence, establishing reference emissions levels that do not reward business-as-usual and having a measuring, reporting and verification system in place are essential elements in implementing successful REDD schemes. To assess the combined impacts of climate and land-use change on tropical forest carbon stocks in the 21st century, we use a dynamic global vegetation model (LPJ DGVM) driven by five different climate change projections under a given greenhouse gas emission scenario (SRES A2) and two contrasting land-use change scenarios. We find that even under a complete stop of deforestation after the period of the Kyoto Protocol (post-2012) some countries may continue to lose carbon stocks due to climate change. Especially at risk is tropical Latin America, although the presence and magnitude of the risk depends on the climate change scenario. By contrast, strong protection of forests could increase carbon uptake in many tropical countries, due to CO 2 fertilization effects, even under altered climate regimes.

  16. Climatic change and environmental implications in the Medicine Hat region using Billings, Montana as an analogue

    International Nuclear Information System (INIS)

    Proudfoot, W.A.

    1994-01-01

    There is concern that climatic change due to anthropogenic enhancement of the greenhouse effect may have considerable impacts on the natural and agricultural environments in Canada. The Palliser Triangle in the southern prairie region is an area in which the impacts of climatic change could be significant; it is an important agricultural zone and is already sensitive due to its semi-arid climate. The possible effects of a change in the climate of the Medicine Hat (Alberta) area in the Palliser Triangle is examined through the use of a regional analogue in a warmer, more southerly area. The selected analogue region is the area around Billings, Montana. Aspects of the natural environment, including potential vegetation distribution, frost-free period, and drought, as well as aspects of the agricultural environment, including agricultural practices and examination of wheat yields, are studied within each region. Comparisons are drawn between the two regions to evaluate whether significant differences exist in the environmental aspects examined. It is shown that although a change in Medicine Hat's climate to one more like that of Billings may not have drastic impacts on the environment, such a change may require adjustments in current practices or adaptations to altered environmental conditions. Reviews of several policy areas will be necessary to ensure appropriate adjustments in agricultural or resource management practices. Regional analogy is shown to be an essential preliminary tool for determining possible effects of climatic change. 138 refs., 42 figs., 22 tabs

  17. Global change in marine ecosystems: implications for semi-enclosed Arabian seas

    KAUST Repository

    Duarte, Carlos M.

    2015-12-07

    Global Change has been defined as the impact of human activities on the key processes that determine the functioning of the Biosphere. Global Change is a major threat for marine ecosystems and includes climate change as well as other global impacts such as inputs of pollutants, overfishing and coastal sprawl. The Semi-enclosed Arabian Seas, including the Arabian Gulf and the Red Sea, have supported human livelihoods in the Arabian Peninsula over centuries and continue to do so, but are also threatened by Global Change. These threats are particularly severe as Semi-enclosed Arabian Seas already present rather extreme conditions, in terms of temperature, salinity and oxygen concentration. The vulnerability of the unique marine ecosystems of the Semi-enclosed Arabian Seas to Global Change vectors is largely unknown, but predictions based on first principles suggest that they may be at or near the tipping point for many pressures, such as warming and hypoxia. There is an urgent need to implement international collaborative research programs to accelerate our understanding of the vulnerability of Semi-enclosed Arabian Seas to Global Change vectors in order to inform conservation and management plans to ensure these Seas continue to support the livelihoods and well-being of the Arab nations.

  18. Permeability Tests on Silkeborg Sand No. 0000

    DEFF Research Database (Denmark)

    Lund, Willy; Jakobsen, Kim Parsberg

    on the characteristics of the soil matrix, the permeability is determined for different void ratios. All tests are performed on reconstituted specimens of Silkeborg Sand No. 0000. The permeability is determined by use of a falling head apparatus. The apparatus, test procedures and the analysis method are described......The flow through porous media plays an important role in various engineering disciplines, as for example in ground water hydrology and soil mechanics. In the present study the permeability is determined for a fine, saturated sand. As the flow through a porous media strongly depends...

  19. Permeability Tests on Eastern Scheldt Sand

    DEFF Research Database (Denmark)

    Jakobsen, Kim Parsberg

    on the characteristics of the soil matrix, the permeability is determined for different void ratios. All tests are performed on reconstituted specimens of Eastern Scheldt Sand. The permeability is determined by use of a falling head apparatus. Finally the test results are briefly summarised and a relationship between......The flow through porous media plays an important role in various engineering disciplines, as for example in ground water hydrology and soil mechanics. In the present study the permeability is determined for a fine, saturated sand. As the flow through a porous media strongly depends...

  20. The complex initial reluctivity, permeability and susceptibility spectra of magnetic materials

    Science.gov (United States)

    Hamilton, N. C.

    2015-03-01

    The HF complex permeability spectrum of a magnetic material is deduced from the measured impedance spectrum, which is then normalized to a series permeability spectrum. However, this series permeability spectrum has previously been shown to correspond to a parallel magnetic circuit, which is not appropriate. Some of the implications of this truth are examined. This electric/magnetic duality has frustrated efforts to interpret the shape of the complex magnetic permeability spectra of materials, and has hindered the application of impedance spectroscopy to magnetic materials. In the presence of magnetic loss, the relationship between the relative magnetic permeability and the magnetic susceptibility is called into question. The use of reluctivity spectra for expressing magnetic material properties is advocated. The relative loss factor, tanδm/μi is shown to be an approximation for the imaginary part of the reluctivity. A single relaxation model for the initial reluctivity spectra of magnetic materials is presented, and its principles are applied to measurements of a high permeability ferrite. The results are presented as contour plots of the spectra as a function of temperature.

  1. Oral Supplementation with Bovine Colostrum Decreases Intestinal Permeability and Stool Concentrations of Zonulin in Athletes.

    Science.gov (United States)

    Hałasa, Maciej; Maciejewska, Dominika; Baśkiewicz-Hałasa, Magdalena; Machaliński, Bogusław; Safranow, Krzysztof; Stachowska, Ewa

    2017-04-08

    Increased intestinal permeability has been implicated in various pathologies, has various causes, and can develop during vigorous athletic training. Colostrum bovinum is a natural supplement with a wide range of supposed positive health effects, including reduction of intestine permeability. We assessed influence of colostrum supplementation on intestinal permeability related parameters in a group of 16 athletes during peak training for competition. This double-blind placebo-controlled study compared supplementation for 20 days with 500 mg of colostrum bovinum or placebo (whey). Gut permeability status was assayed by differential absorption of lactulose and mannitol (L/M test) and stool zonulin concentration. Baseline L/M tests found that six of the participants (75%) in the colostrum group had increased intestinal permeability. After supplementation, the test values were within the normal range and were significantly lower than at baseline. The colostrum group Δ values produced by comparing the post-intervention and baseline results were also significantly lower than the placebo group Δ values. The differences in stool zonulin concentration were smaller than those in the L/M test, but were significant when the Δ values due to intervention were compared between the colostrum group and the placebo group. Colostrum bovinum supplementation was safe and effective in decreasing of intestinal permeability in this series of athletes at increased risk of its elevation.

  2. Oral Supplementation with Bovine Colostrum Decreases Intestinal Permeability and Stool Concentrations of Zonulin in Athletes

    Directory of Open Access Journals (Sweden)

    Maciej Hałasa

    2017-04-01

    Full Text Available Increased intestinal permeability has been implicated in various pathologies, has various causes, and can develop during vigorous athletic training. Colostrum bovinum is a natural supplement with a wide range of supposed positive health effects, including reduction of intestine permeability. We assessed influence of colostrum supplementation on intestinal permeability related parameters in a group of 16 athletes during peak training for competition. This double-blind placebo-controlled study compared supplementation for 20 days with 500 mg of colostrum bovinum or placebo (whey. Gut permeability status was assayed by differential absorption of lactulose and mannitol (L/M test and stool zonulin concentration. Baseline L/M tests found that six of the participants (75% in the colostrum group had increased intestinal permeability. After supplementation, the test values were within the normal range and were significantly lower than at baseline. The colostrum group Δ values produced by comparing the post-intervention and baseline results were also significantly lower than the placebo group Δ values. The differences in stool zonulin concentration were smaller than those in the L/M test, but were significant when the Δ values due to intervention were compared between the colostrum group and the placebo group. Colostrum bovinum supplementation was safe and effective in decreasing of intestinal permeability in this series of athletes at increased risk of its elevation.

  3. Implications of projected climate change for groundwater recharge in the western United States

    Science.gov (United States)

    Meixner, Thomas; Manning, Andrew H.; Stonestrom, David A.; Allen, Diana M.; Ajami, Hoori; Blasch, Kyle W.; Brookfield, Andrea E.; Castro, Christopher L.; Clark, Jordan F.; Gochis, David J.; Flint, Alan L.; Neff, Kirstin L.; Niraula, Rewati; Rodell, Matthew; Scanlon, Bridget R.; Singha, Kamini; Walvoord, Michelle A.

    2016-03-01

    Existing studies on the impacts of climate change on groundwater recharge are either global or basin/location-specific. The global studies lack the specificity to inform decision making, while the local studies do little to clarify potential changes over large regions (major river basins, states, or groups of states), a scale often important in the development of water policy. An analysis of the potential impact of climate change on groundwater recharge across the western United States (west of 100° longitude) is presented synthesizing existing studies and applying current knowledge of recharge processes and amounts. Eight representative aquifers located across the region were evaluated. For each aquifer published recharge budget components were converted into four standard recharge mechanisms: diffuse, focused, irrigation, and mountain-systems recharge. Future changes in individual recharge mechanisms and total recharge were then estimated for each aquifer. Model-based studies of projected climate-change effects on recharge were available and utilized for half of the aquifers. For the remainder, forecasted changes in temperature and precipitation were logically propagated through each recharge mechanism producing qualitative estimates of direction of changes in recharge only (not magnitude). Several key patterns emerge from the analysis. First, the available estimates indicate average declines of 10-20% in total recharge across the southern aquifers, but with a wide range of uncertainty that includes no change. Second, the northern set of aquifers will likely incur little change to slight increases in total recharge. Third, mountain system recharge is expected to decline across much of the region due to decreased snowpack, with that impact lessening with higher elevation and latitude. Factors contributing the greatest uncertainty in the estimates include: (1) limited studies quantitatively coupling climate projections to recharge estimation methods using detailed

  4. Implications of projected climate change for groundwater recharge in the western United States

    Science.gov (United States)

    Meixner, Thomas; Manning, Andrew H.; Stonestrom, David A.; Allen, Diana M.; Ajami, Hoori; Blasch, Kyle W.; Brookfield, Andrea E.; Castro, Christopher L.; Clark, Jordan F.; Gochis, David; Flint, Alan L.; Neff, Kirstin L.; Niraula, Rewati; Rodell, Matthew; Scanlon, Bridget R.; Singha, Kamini; Walvoord, Michelle Ann

    2016-01-01

    Existing studies on the impacts of climate change on groundwater recharge are either global or basin/location-specific. The global studies lack the specificity to inform decision making, while the local studies do little to clarify potential changes over large regions (major river basins, states, or groups of states), a scale often important in the development of water policy. An analysis of the potential impact of climate change on groundwater recharge across the western United States (west of 100° longitude) is presented synthesizing existing studies and applying current knowledge of recharge processes and amounts. Eight representative aquifers located across the region were evaluated. For each aquifer published recharge budget components were converted into four standard recharge mechanisms: diffuse, focused, irrigation, and mountain-systems recharge. Future changes in individual recharge mechanisms and total recharge were then estimated for each aquifer. Model-based studies of projected climate-change effects on recharge were available and utilized for half of the aquifers. For the remainder, forecasted changes in temperature and precipitation were logically propagated through each recharge mechanism producing qualitative estimates of direction of changes in recharge only (not magnitude). Several key patterns emerge from the analysis. First, the available estimates indicate average declines of 10–20% in total recharge across the southern aquifers, but with a wide range of uncertainty that includes no change. Second, the northern set of aquifers will likely incur little change to slight increases in total recharge. Third, mountain system recharge is expected to decline across much of the region due to decreased snowpack, with that impact lessening with higher elevation and latitude. Factors contributing the greatest uncertainty in the estimates include: (1) limited studies quantitatively coupling climate projections to recharge estimation methods using

  5. The Dynamics of Vulnerability and Implications for Climate Change Adaptation: Lessons from Urban Water Management

    Science.gov (United States)

    Dilling, L.; Daly, M.; Travis, W.; Wilhelmi, O.; Klein, R.; Kenney, D.; Ray, A. J.; Miller, K.

    2013-12-01

    Recent reports and scholarship have suggested that adapting to current climate variability may represent a "no regrets" strategy for adapting to climate change. Filling "adaptation deficits" and other approaches that rely on addressing current vulnerabilities are of course helpful for responding to current climate variability, but we find here that they are not sufficient for adapting to climate change. First, following a comprehensive review and unique synthesis of the natural hazards and climate adaptation literatures, we advance six reasons why adapting to climate variability is not sufficient for adapting to climate change: 1) Vulnerability is different at different levels of exposure; 2) Coping with climate variability is not equivalent to adaptation to longer term change; 3) The socioeconomic context for vulnerability is constantly changing; 4) The perception of risk associated with climate variability does not necessarily promote adaptive behavior in the face of climate change; 5) Adaptations made to short term climate variability may reduce the flexibility of the system in the long term; and 6) Adaptive actions may shift vulnerabilities to other parts of the system or to other people. Instead we suggest that decision makers faced with choices to adapt to climate change must consider the dynamics of vulnerability in a connected system-- how choices made in one part of the system might impact other valued outcomes or even create new vulnerabilities. Furthermore we suggest that rather than expressing climate change adaptation as an extension of adaptation to climate variability, the research and practice communities would do well to articulate adaptation as an imperfect policy, with tradeoffs and consequences and that decisions be prioritized to preserve flexibility be revisited often as climate change unfolds. We then present the results of a number of empirical studies of decision making for drought in urban water systems in the United States to understand

  6. Implications of changing water cycle for the performance and yield characteristics of the multi-purpose Beas Reservoir in India

    Science.gov (United States)

    Adeloye, A. J.; Ojha, C. S.; Soundharajan, B.; Remesan, R.

    2013-12-01

    There is considerable change in both the spatial and temporal patterns of monsoon rainfall in India, with implications for water resources availability and security. 'Mitigating the Impacts of Climate Change on India Agriculture' (MICCI) is one of five on-going scientific efforts being sponsored as part of the UK-NERC/India-MOES Changing Water Cycle (South Asia) initiative to further the understanding of the problem and proffer solutions that are robust and effective. This paper focuses on assessing the implications of projected climate change on the yield and performance characteristics of the Pong Reservoir on the Beas River, Himachal Pradesh, India. The Pong serves both hydropower and irrigation needs and is therefore strategic for the socio-economic well-being of the region as well as sustaining the livelihoods of millions of farmers that rely on it for irrigation. Simulated baseline and climate-change perturbed hydro-climate scenarios developed as part of a companion Work Package of MICCI formed the basis of the analysis. For both of these scenarios, reservoir analyses were carried out using the Sequent Peak Algorithm (SPA) and Pong's existing level of releases to derive rule curves for the reservoir. These rule curves then formed the basis of further reservoir behaviour simulations in WEAP and the resulting performance of the reservoir was summarised in terms of reliability, resilience, vulnerability and sustainability. The whole exercise was implemented within a Monte Carlo framework for the benefit of characterising the variability in the assessments. The results show that the rule curves developed using future hydro-climate are significantly changed from the baseline in that higher storages will be required to be maintained in the Pong in the future to achieve reliable performance. As far as the overall performance of the reservoir is concerned, future reliability (both time-based and volume-based) is not significantly different from the baseline, provided

  7. Newborn survival in Uganda: a decade of change and future implications.

    Science.gov (United States)

    Mbonye, Anthony K; Sentongo, Miriam; Mukasa, Gelasius K; Byaruhanga, Romano; Sentumbwe-Mugisa, Olive; Waiswa, Peter; Naamala Sengendo, Hanifah; Aliganyira, Patrick; Nakakeeto, Margaret; Lawn, Joy E; Kerber, Kate

    2012-07-01

    Each year in Uganda 141 000 children die before reaching their fifth birthday; 26% of these children die in their first month of life. In a setting of persistently high fertility rates, a crisis in human resources for health and a recent history of civil unrest, Uganda has prioritized Millennium Development Goals 4 and 5 for child and maternal survival. As part of a multi-country analysis we examined change for newborn survival over the past decade through mortality and health system coverage indicators as well as national and donor funding for health, and policy and programme change. Between 2000 and 2010 Uganda's neonatal mortality rate reduced by 2.2% per year, which is greater than the regional average rate of decline but slower than national reductions in maternal mortality and under-five mortality after the neonatal period. While existing population-based data are insufficient to measure national changes in coverage and quality of services, national attention for maternal and child health has been clear and authorized from the highest levels. Attention and policy change for newborn health is comparatively recent. This recognized gap has led to a specific focus on newborn health through a national Newborn Steering Committee, which has been given a mandate from the Ministry of Health to advise on newborn survival issues since 2006. This multi-disciplinary and inter-agency network of stakeholders has been able to preside over a number of important policy changes at the level of facility care, education and training, community-based service delivery through Village Health Teams and changes to essential drugs and commodities. The committee's comprehensive reach has enabled rapid policy change and increased attention to newborn survival in a relatively short space of time. Translating this favourable policy environment into district-level implementation and high quality services is now the priority.

  8. Flow regime alterations under changing climate in two river basins: Implications for freshwater ecosystems

    Science.gov (United States)

    Gibson, C.A.; Meyer, J.L.; Poff, N.L.; Hay, L.E.; Georgakakos, A.

    2005-01-01

    We examined impacts of future climate scenarios on flow regimes and how predicted changes might affect river ecosystems. We examined two case studies: Cle Elum River, Washington, and Chattahoochee-Apalachicola River Basin, Georgia and Florida. These rivers had available downscaled global circulation model (GCM) data and allowed us to analyse the effects of future climate scenarios on rivers with (1) different hydrographs, (2) high future water demands, and (3) a river-floodplain system. We compared observed flow regimes to those predicted under future climate scenarios to describe the extent and type of changes predicted to occur. Daily stream flow under future climate scenarios was created by either statistically downscaling GCMs (Cle Elum) or creating a regression model between climatological parameters predicted from GCMs and stream flow (Chattahoochee-Apalachicola). Flow regimes were examined for changes from current conditions with respect to ecologically relevant features including the magnitude and timing of minimum and maximum flows. The Cle Elum's hydrograph under future climate scenarios showed a dramatic shift in the timing of peak flows and lower low flow of a longer duration. These changes could mean higher summer water temperatures, lower summer dissolved oxygen, and reduced survival of larval fishes. The Chattahoochee-Apalachicola basin is heavily impacted by dams and water withdrawals for human consumption; therefore, we made comparisons between pre-large dam conditions, current conditions, current conditions with future demand, and future climate scenarios with future demand to separate climate change effects and other anthropogenic impacts. Dam construction, future climate, and future demand decreased the flow variability of the river. In addition, minimum flows were lower under future climate scenarios. These changes could decrease the connectivity of the channel and the floodplain, decrease habitat availability, and potentially lower the ability

  9. Climate Change in the Seychelles: Implications for Water and Coral Reefs

    Energy Technology Data Exchange (ETDEWEB)

    Payet, Rolph; Agricole, Wills [National Meteorological Services Mahe (Seychelles). Div. of Policy, Planning and Services

    2006-06-15

    The Seychelles is a small island state in the western Indian Ocean that is vulnerable to the effects of climate change. This vulnerability led the Intergovernmental Panel on Climate Change (IPCC) in 2001 to express concern over the potential economic and social consequences that may be faced by small island states. Small island states should be prepared to adapt to such changes, especially in view of their dependence on natural resources, such as water and coral reefs, to meet basic human welfare needs. Analysis of long-term data for precipitation, air temperature, and sea-surface temperature indicated that changes are already observable in the Seychelles. The increase in dry spells that resulted in drought conditions in 1999 and the 1998 mass coral bleaching are indicative of the events that are likely to occur under future climate change. Pre-IPCC Third Assessment Report scenarios and the new SRES scenarios are compared for changes in precipitation and air surface temperature for the Seychelles. These intercomparisons indicate that the IS92 scenarios project a much warmer and wetter climate for the Seychelles than do the SRES scenarios. However, a wetter climate does not imply readily available water, but rather longer dry spells with more intense precipitation events. These observations will likely place enormous pressures on water-resources management in the Seychelles. Similarly, sea-surface temperature increases predicted by the HADCm{sup 3} model will likely trigger repeated coral-bleaching episodes, with possible coral extinctions within the Seychelles region by 2040. The cover of many coral reefs around the Seychelles have already changed, and the protection of coral-resilient areas is a critical adaptive option.

  10. Contextual change after fear acquisition affects conditioned responding and the time course of extinction learning – Implications for renewal research

    Directory of Open Access Journals (Sweden)

    Rachel eSjouwerman

    2015-12-01

    Full Text Available Context plays a central role in retrieving (fear memories. Accordingly, context manipulations are inherent to most return of fear (ROF paradigms (in particular renewal, involving contextual changes after fear extinction. Context changes are, however, also often embedded during earlier stages of ROF experiments such as context changes between fear acquisition and extinction (e.g. in ABC and ABA renewal. Previous studies using these paradigms have however focused exclusively on the context switch after extinction (i.e. renewal. Thus, the possibility of a general effect of a context switch on conditioned responding that may not be conditional to preceding extinction learning remains unstudied.Hence, the current study investigated the impact of a context switch between fear acquisition and extinction on immediate conditioned responding and on the time-course of extinction learning by using a multimodal approach. A group that underwent contextual change after fear conditioning (AB; n = 36 was compared with a group without a contextual change from acquisition to extinction (AA; n = 149, while measuring autonomic (skin conductance and fear potentiated startle measures and subjective fear ratings. Contextual change between fear acquisition and extinction had a pronounced effect on both immediate conditioned responding and on the time course of extinction learning in skin conductance responses and subjective fear ratings. This may have important implications for the mechanisms underlying and the interpretation of the renewal effect (i.e. contextual switch after extinction. Consequently, future studies should incorporate designs and statistical tests that disentangle general effects of contextual change from genuine ROF effects.

  11. Bioinspired Layer-by-Layer Microcapsules Based on Cellulose Nanofibers with Switchable Permeability

    DEFF Research Database (Denmark)

    Paulraj, Thomas; Riazanova, Anastasia V; Yao, Kun

    2017-01-01

    Green, all-polysaccharide based microcapsules with mechanically robust capsule walls and fast, stimuli-triggered, and switchable permeability behavior show great promise in applications based on selective and timed permeability. Taking a cue from nature, the build-up and composition of plant......-by-layer technique on sacrificial CaCO3 templates, using plant polysaccharides (pectin, cellulose nanofibers, and xyloglucan) only. In water, the capsule wall was permeable to labeled dextrans with a hydrodynamic diameter of ∼6.6 nm. Upon exposure to NaCl, the porosity of the capsule wall quickly changed allowing...

  12. The implications of starvation induced psychological changes for the ethical treatment of hunger strikers.

    Science.gov (United States)

    Fessler, D M T

    2003-08-01

    To evaluate existing ethical guidelines for the treatment of hunger strikers in light of findings on psychological changes that accompany the cessation of food intake. Electronic databases were searched for (a) editorials and ethical proclamations on hunger strikers and their treatment; (b) studies of voluntary and involuntary starvation, and (c) legal cases pertaining to hunger striking. Additional studies were gathered in a snowball fashion from the published material cited in these databases. Material was included if it (a) provided ethical or legal guidelines; (b) shed light on psychological changes accompanying starvation, or (c) illustrated the practice of hunger striking. Authors' observations, opinions, and conclusions were noted. Although the heterogeneous nature of the sources precluded statistical analysis, starvation appears to be accompanied by marked psychological changes. Some changes clearly impair competence, in which case physicians are advised to follow advance directives obtained early in the hunger strike. More problematic are increases in impulsivity and aggressivity, changes which, while not impairing competence, enhance the likelihood that patients will starve themselves to death.

  13. The Changing Health Care Landscape and Implications of Organizational Ethics on Modern Medical Practice.

    Science.gov (United States)

    Castlen, Joseph P; Cote, David J; Moojen, Wouter A; Robe, Pierre A; Balak, Naci; Brennum, Jannick; Ammirati, Mario; Mathiesen, Tiit; Broekman, Marike L D

    2017-06-01

    Medicine is rapidly changing, both in the level of collective medical knowledge and in how it is being delivered. The increased presence of administrators in hospitals helps to facilitate these changes and ease administrative workloads on physicians; however, tensions sometimes form between physicians and administrators. This situation is based on perceptions from both sides that physicians obstruct cost-saving measures and administrators put profits before patients. In reality, increasing patient populations and changes in health care are necessitating action by hospitals to prevent excessive spending as health care systems become larger and more difficult to manage. Recognizing the cause of changes in health care, which do not always originate with physicians and administrators, along with implementing changes in hospitals such as increased physician leadership, could help to ease tensions and promote a more collaborative atmosphere. Ethically, there is a need to preserve physician autonomy, which is a tenet of medical professionalism, and a need to rein in spending costs and ensure that patients receive the best possible care. Physicians and administrators both need to have a well-developed personal ethic to achieve these goals. Physicians need be allowed to retain relative autonomy over their practices as they support and participate in administrator-led efforts toward distributive justice. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. The impact of climate change and emissions control on future ozone levels: Implications for human health.

    Science.gov (United States)

    Stowell, Jennifer D; Kim, Young-Min; Gao, Yang; Fu, Joshua S; Chang, Howard H; Liu, Yang

    2017-11-01

    Overwhelming evidence has shown that, from the Industrial Revolution to the present, human activities influence ground-level ozone (O 3 ) concentrations. Past studies demonstrate links between O 3 exposure and health. However, knowledge gaps remain in our understanding concerning the impacts of climate change mitigation policies on O 3 concentrations and health. Using a hybrid downscaling approach, we evaluated the separate impact of climate change and emission control policies on O 3 levels and associated excess mortality in the US in the 2050s under two Representative Concentration Pathways (RCPs). We show that, by the 2050s, under RCP4.5, increased O 3 levels due to combined climate change and emission control policies, could contribute to an increase of approximately 50 premature deaths annually nationwide in the US. The biggest impact, however, is seen under RCP8.5, where rises in O 3 concentrations are expected to result in over 2,200 additional premature deaths annually. The largest increases in O 3 are seen in RCP8.5 in the Northeast, the Southeast, the Central, and the West regions of the US. Additionally, when O 3 increases are examined by climate change and emissions contributions separately, the benefits of emissions mitigation efforts may significantly outweigh the effects of climate change mitigation policies on O 3 -related mortality. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Global climate change: Some implications, opportunities, and challenges for US forestry

    International Nuclear Information System (INIS)

    Marland, G.

    1991-01-01

    It is widely agreed that the concentration of greenhouse gases in the earth's atmosphere is increasing, that this increase is a consequence of man's activities, and that there is significant risk that this will lead to changes in the earth's climate. The question is now being discussed what, if anything, we should be doing to minimize and/or adapt to changes in climate. Virtually every statement on this matter; from the US Office of Technology Assessment, to the National Academy of Science, to the Nairobi Declaration on Climatic Change, includes some recommendation for planting and protecting forests. In fact, forestry is intimately involved in the climate change debate for several reasons: changing climate patterns will affect existing forests, tropical deforestation is one of the major sources of greenhouse gases to the atmosphere, reforestation projects could remove additional carbon dioxide from the atmosphere and there is renewed interest in wood-based or other renewable fuels to replace fossil fuels. Part of the enthusiasm for forestry-related strategies in a greenhouse context is the perception that forests not only provide greenhouse benefits but also serve other desirable social objectives. This discussion will explore the current range of thinking in this area and try to stimulate additional thinking on the rationality of the forestry-based approaches and the challenges posed for US forestry

  16. Changes in population characteristics and their implication on public health research.

    Science.gov (United States)

    Du, Ping; Coles, F Bruce; O'Campo, Patricia; McNutt, Louise-Anne

    2007-07-10

    Population estimates are generally drawn from one point in time to study disease trends over time; changes in population characteristics over time are usually not assessed and included in the study design. We evaluated whether population characteristics remained static and assessed the degree of population shifts over time. The analysis was based on the New York State 1990 and 2000 census data with adjustments for changes in geographic boundaries. Differences in census tract information were quantified by calculating the mean, median, standard deviation, and the percent of change for each population characteristic. Between 1990 and 2000, positive and negative fluctuations in population size created a U-shaped bimodal pattern of population change which increased the disparities in demographics and socioeconomic status for many census tracts. While 268 (10%) census tracts contracted by 10%, twice as many census tracts (21%, N = 557) grew at least 10%. Notably, the non-Hispanic African-American population grew 10% or more in 152 tracts. Although there were overall reductions in working class and undereducated populations and gains in incomes, most census tracts experienced growing income inequalities and an increased poverty rate. These changes were most pronounced in urban census tracts. Differences in population characteristics in a decade showed growing disparities in demographics and socioeconomic status. This study elucidates that important population shifts should be taken into account when conducting longitudinal research.

  17. VECTORS of change in the marine environment: Ecosystem and economic impacts and management implications

    Science.gov (United States)

    Austen, M. C.; Crowe, T. P.; Elliott, M.; Paterson, D. M.; Peck, M. A.; Piraino, S.

    2018-02-01

    Human use of the European marine environment is increasing and diversifying. This is creating new mechanisms for human induced-changes in marine life which need to be understood and quantified as well as the impact of these changes on ecosystems, their structures (e.g. biodiversity) and functioning (e.g. productivity), and the social and economic consequences that arise. The current and emerging pressures are multiple and interacting, arising, for example, from transport, platforms for renewable and non-renewable energy, exploitation of living and non-living resources, agricultural and industrial discharges, together with wider environmental changes (including climate change). Anticipating the future consequences of these pressures and vectors of change for marine life and of adaptation and mitigation measures (such as the introduction of new technologies and structures, new ballast water practices, ocean and offshore wind energy devices and new fishing strategies) is a prerequisite to the development and implementation of strategies, policies and regulations to manage the marine environment, such as the IMO Convention on ballast water management and the EU Maritime Policy and Marine Strategy Framework Directive.

  18. Interpretation of changes in water level accompanying fault creep and implications for earthquake prediction.

    Science.gov (United States)

    Wesson, R.L.

    1981-01-01

    Quantitative calculations for the effect of a fault creep event on observations of changes in water level in wells provide an approach to the tectonic interpretation of these phenomena. For the pore pressure field associated with an idealized creep event having an exponential displacement versus time curve, an analytic expression has been obtained in terms of exponential-integral functions. The pore pressure versus time curves for observation points near the fault are pulselike; a sharp pressure increase (or decrease, depending on the direction of propagation) is followed by more gradual decay to the normal level after the creep event. The time function of the water level change may be obtained by applying the filter - derived by A.G.Johnson and others to determine the influence of atmospheric pressure on water level - to the analytic pore pressure versus time curves. The resulting water level curves show a fairly rapid increase (or decrease) and then a very gradual return to normal. The results of this analytic model do not reproduce the steplike changes in water level observed by Johnson and others. If the procedure used to obtain the water level from the pore pressure is correct, these results suggest that steplike changes in water level are not produced by smoothly propagating creep events but by creep events that propagate discontinuously, by changes in the bulk properties of the region around the well, or by some other mechanism.-Author

  19. Contrasting environmental drivers of adult and juvenile growth in a marine fish: implications for the effects of climate change.

    Science.gov (United States)

    Ong, Joyce Jia Lin; Rountrey, Adam Nicholas; Meeuwig, Jessica Jane; Newman, Stephen John; Zinke, Jens; Meekan, Mark Gregory

    2015-06-08

    Many marine fishes have life history strategies that involve ontogenetic changes in the use of coastal habitats. Such ontogenetic shifts may place these species at particular risk from climate change, because the successive environments they inhabit can differ in the type, frequency and severity of changes related to global warming. We used a dendrochronology approach to examine the physical and biological drivers of growth of adult and juvenile mangrove jack (Lutjanus argentimaculatus) from tropical north-western Australia. Juveniles of this species inhabit estuarine environments and adults reside on coastal reefs. The Niño-4 index, a measure of the status of the El Niño-Southern Oscillation (ENSO) had the highest correlation with adult growth chronologies, with La Niña years (characterised by warmer temperatures and lower salinities) having positive impacts on growth. Atmospheric and oceanographic phenomena operating at ocean-basin scales seem to be important correlates of the processes driving growth in local coastal habitats. Conversely, terrestrial factors influencing precipitation and river runoff were positively correlated with the growth of juveniles in estuaries. Our results show that the impacts of climate change on these two life history stages are likely to be different, with implications for resilience and management of populations.

  20. The climate change implications of manufacturing refrigerants. A calculation of 'production' energy contents of some common refrigerants

    International Nuclear Information System (INIS)

    Campbell, N.J.; McCulloch, A.

    1998-01-01

    Total Equivalent Warming Impact (TEWI) analysis has been shown to be a useful aid to quantifying the climate change effect of potential emissions from the operation of systems that involve the use of greenhouse gases and consume energy, so generating CO 2 emissions. It enables these systems to be optimized for minimum global warming impact. In previous studies, the energies required to manufacture the greenhouse gases themselves were not included; by analogy with other chemical manufacturing processes they were assumed to be small in the context of climate change. In the work described here, climate change impacts from the energy used to produce a number of common refrigerant fluids are evaluated. These impacts are compared with the potential impact on global warming from the other components of TEWI: use and disposal of the refrigerants, including direct release into the environment. It is shown that the implications for climate change of the production of traditional refrigerants like ammonia, hydrocarbons or CFC-12 and new refrigerating fluids, such as HFC-134a, are truly insignificant in comparison with other stages of the life cycle of a refrigerator and have no role in TEWI. (author)

  1. The changing landscape of pulmonary arterial hypertension and implications for patient care

    Directory of Open Access Journals (Sweden)

    Marius M. Hoeper

    2014-12-01

    Full Text Available Registries have provided a wealth of information on the clinical and disease characteristics of patients living with pulmonary arterial hypertension (PAH since the 1980s. Certain PAH demographics, such as the prevalence of various PAH subgroups and preponderance of female patients, appear to have remained stable over time. Contemporary registry data indicate that the average age of patients diagnosed with PAH has increased, at least in the Western world. Older patients with PAH are more likely to be diagnosed with a more advanced stage of the disease, have lower exercise capacity and present with multiple comorbidities. They also have worse survival compared with younger patients. Within the PAH population, there is also a subset of patients with a lower diffusing capacity of the lung for carbon monoxide who are generally older and display more severe disease characteristics. This review discusses the implications that the increased age of the PAH population at diagnosis has on the treatment and management of the disease, as well as the need for earlier and improved diagnosis in these patients.

  2. Addressing potential local adaptation in species distribution models: implications for conservation under climate change

    Science.gov (United States)

    Hällfors, Maria Helena; Liao, Jishan; Dzurisin, Jason D. K.; Grundel, Ralph; Hyvärinen, Marko; Towle, Kevin; Wu, Grace C.; Hellmann, Jessica J.

    2016-01-01

    Species distribution models (SDMs) have been criticized for involving assumptions that ignore or categorize many ecologically relevant factors such as dispersal ability and biotic interactions. Another potential source of model error is the assumption that species are ecologically uniform in their climatic tolerances across their range. Typically, SDMs to treat a species as a single entity, although populations of many species differ due to local adaptation or other genetic differentiation. Not taking local adaptation into account, may lead to incorrect range prediction and therefore misplaced conservation efforts. A constraint is that we often do not know the degree to which populations are locally adapted, however. Lacking experimental evidence, we still can evaluate niche differentiation within a species' range to promote better conservation decisions. We explore possible conservation implications of making type I or type II errors in this context. For each of two species, we construct three separate MaxEnt models, one considering the species as a single population and two of disjunct populations. PCA analyses and response curves indicate different climate characteristics in the current environments of the populations. Model projections into future climates indicate minimal overlap between areas predicted to be climatically suitable by the whole species versus population-based models. We present a workflow for addressing uncertainty surrounding local adaptation in SDM application and illustrate the value of conducting population-based models to compare with whole-species models. These comparisons might result in more cautious management actions when alternative range outcomes are considered.

  3. Breaking bad news revisited: the push for negotiated disclosure and changing practice implications.

    Science.gov (United States)

    Arber, Anne; Gallagher, Ann

    2003-04-01

    This article revisits the ethical, legal, professional and emotional issues involved with disclosing bad news. The authors examine the push for disclosure that has come from a number of quarters in the UK, including ethical and legal challenges, in particular the Bristol Royal Inquiry Report, professional codes of conduct, health policy and the expectations of the public. The contribution of nurses to breaking bad news is not widely discussed in the literature. With the development of new nursing roles and evidence-based practice it is timely to consider the role of nurses in this process. The article highlights some limitations with current guidelines for breaking bad news, in particular, that these guidelines tend to be constructed from a professional standpoint and lack patient-centred evidence. The issue of emotional labour and how it relates to giving bad news is discussed with respect to professional staff and patients. The article concludes by raising some practice implications, including: the importance of context and continuity; the significance of information and support; the desirable qualities of the professional; and issues to consider in determining patient preferences.

  4. Changes in interstitial K+ and pH during exercise: implications for blood flow regulation

    DEFF Research Database (Denmark)

    Juel, Carsten

    2007-01-01

    that blood flow is affected by changes in K+ as low as 0.1 mmol/L. The vasodilatory effect of K+ can be inhibited with simultaneous barium infusion, indicating that inward rectifier potassium (Kir)channels are involved. Acidosis has a direct effect on blood flow and an indirect effect, mediated by changes...... with the microdialysis technique. Interstitial K+ accumulation is dependent on the intensity and duration of muscle activity and may reach 10 mmol/L during intense exercise, and the concentration in T-tubules may be even higher. Thus, interstitial K+ can reach a level that affects fibre excitability and the development...... of fatigue. It has also been demonstrated with microdialysis that the interstitial decrease in pH during muscle activity is larger than the reduction in blood pH. Ion changes in the interstitium may affect blood flow directly or indirectly. Infusion of K+ into the femoral artery in humans has demonstrated...

  5. Implications of rapid environmental change for polar bear behavior and sociality

    Science.gov (United States)

    Atwood, Todd C.

    2017-01-01

    Historically, the Arctic sea ice has functioned as a structural barrier that has limited the nature and extent of interactions between humans and polar bears (Ursus maritimus). However, declining sea ice extent, brought about by global climate change, is increasing the potential for human-polar bear interactions. Loss of sea ice habitat is driving changes to both human and polar bear behavior—it is facilitating increases in human activities (e.g., offshore oil and gas exploration and extraction, trans-Arctic shipping, recreation), while also causing the displacement of bears from preferred foraging habitat (i.e., sea ice over biologically productive shallow) to land in some portions of their range. The end result of these changes is that polar bears are spending greater amounts of time in close proximity to people. Coexistence between humans and polar bears will require imposing mechanisms to manage further development, as well as mitigation strategies that reduce the burden to local communities.

  6. Justice and Equity Implications of Climate Change Adaptation: A Theoretical Evaluation Framework

    Science.gov (United States)

    Boeckmann, Melanie; Zeeb, Hajo

    2016-01-01

    Climate change affects human health, and climate change adaptation aims to reduce these risks through infrastructural, behavioral, and technological measures. However, attributing direct human health effects to climate change adaptation is difficult, causing an ethical dilemma between the need for evidence of strategies and their precautionary implementation before such evidence has been generated. In the absence of conclusive evidence for individual adaptation strategies, alternative approaches to the measurement of adaptation effectiveness need to be developed. This article proposes a theoretical framework and a set of guiding questions to assess effects of adaptation strategies on seven domains of health determinants, including social, economic, infrastructure, institutional, community, environmental, and cultural determinants of health. Its focus on advancing gender equity and environmental justice concurrently with the implementation of health-related adaptation could serve as a template for policymakers and researchers. PMID:27618121

  7. Justice and Equity Implications of Climate Change Adaptation: A Theoretical Evaluation Framework

    Directory of Open Access Journals (Sweden)

    Melanie Boeckmann

    2016-09-01

    Full Text Available Climate change affects human health, and climate change adaptation aims to reduce these risks through infrastructural, behavioral, and technological measures. However, attributing direct human health effects to climate change adaptation is difficult, causing an ethical dilemma between the need for evidence of strategies and their precautionary implementation before such evidence has been generated. In the absence of conclusive evidence for individual adaptation strategies, alternative approaches to the measurement of adaptation effectiveness need to be developed. This article proposes a theoretical framework and a set of guiding questions to assess effects of adaptation strategies on seven domains of health determinants, including social, economic, infrastructure, institutional, community, environmental, and cultural determinants of health. Its focus on advancing gender equity and environmental justice concurrently with the implementation of health-related adaptation could serve as a template for policymakers and researchers.

  8. Implications of Age-Related Changes in Anatomy for Geriatric-Focused Difficult Airways

    Directory of Open Access Journals (Sweden)

    Shih-Yi Lee

    2017-09-01

    Full Text Available The structure and function surrounding the airway change by the age, which may ultimately result in having anatomic features of difficult airways in the elderly. Hence, we reviewed the literature focusing on the age-related anatomic changes and accordingly to compare the characteristics of difficult airways. With age, teeth wear and loss, protein and collagen synthesis reduction, and bone loss and muscle atrophy results in aged face (chin protrusion, cheek retraction and drooping, jaw restriction (temporo-madibular joint disc displacement and osteoarthritis, neck and back stiffness, and kyphotic deformities (degeneration of spinal articular cartilage, intervertebral discs, and spinal osteoporosis. These age-related changes in anatomy are compatible with the predictors of a difficult airway. We hope that these age-related anatomic approaches will prospectively allow a detailed understanding of the hallmarks resulting in geriatric-focused difficult airways in the future studies.

  9. Soil-transmitted helminthiases: implications of climate change and human behavior.

    Science.gov (United States)

    Weaver, Haylee J; Hawdon, John M; Hoberg, Eric P

    2010-12-01

    Soil-transmitted helminthiases (STHs) collectively cause the highest global burden of parasitic disease after malaria and are most prevalent in the poorest communities, especially in sub-Saharan Africa. Climate change is predicted to alter the physical environment through cumulative impacts of warming and extreme fluctuations in temperature and precipitation, with cascading effects on human health and wellbeing, food security and socioeconomic infrastructure. Understanding how the spectrum of climate change effects will influence STHs is therefore of critical importance to the control of the global burden of human parasitic disease. Realistic progress in the global control of STH in a changing climate requires a multidisciplinary approach that includes the sciences (e.g. thermal thresholds for parasite development and resilience) and social sciences (e.g. behavior and implementation of education and sanitation programs). Copyright © 2010 Elsevier Ltd. All rights reserved.

  10. WELFARE IMPLICATIONS OF TIMBERLAND OWNERSHIP CHANGES IN THE U.S. TIMBER MARKETS

    Directory of Open Access Journals (Sweden)

    Mohammad Mahfuzur Rahman

    2016-07-01

    Full Text Available In the last two decades, many forest product firms in the U.S. either divested their timberlands to timber investment management organizations (TIMOs and conservation organizations or converted their corporate structures from C corporations to real estate investment trusts (REITs. All landowners sold smaller timberland tracts for nonforestry uses. Reduced timber supplies from conservation organizations and timberland loss to other nonforestry uses have consequences on producer and consumer surpluses in the U.S. timber markets. Equilibrium displacement model has been employed to evaluate the welfare changes in U.S. timber markets attributed to timberland ownership changes. Net reduction of timber supply contributed to the reduction of social surplus by $43 million in 2006. Compared to the $33 billion plus U.S. timber markets, this welfare reduction was small. Overall, this article explains the shifts of economic surpluses among producers and net surplus reduction for the society attributed to timberland ownership changes in the United States.

  11. [Imaginary dimension and intersubjectivity in public health organizations: implications to managerial work and organizational change].

    Science.gov (United States)

    Azevedo, Creuza da Silva

    2010-06-01

    This paper deals with organization management in a new perspective, stressing the micro-social aspects and the role of individuals in the process of implementing change in public health organizations such as hospitals. Following the paths of French psychosociology, the article approaches the imaginary, intersubjective and collective dimensions of these organizations, highlighting the ways hospitals' directors and employees engage themselves in a struggle for power, affiliation and recognition. An essentially interactive and intersubjective activity, management is examined in the light of psychoanalysis's leadership function. It seems crucial to take into account the directors' potential structuring role in order to understand the organizational changing processes. Nevertheless, the mounting crisis in Rio de Janeiro public health services does not favor change and the building of personal bonds, but disruption, dismantle of institutional affiliations. In this scenario, the management structuring function and the director's social and psychological mediating role lose ground.

  12. Comparative Perspectives on the Changing Business of Journalism and Its Implications for Democracy

    DEFF Research Database (Denmark)

    Nielsen, Rasmus Kleis; Frank, Esser; David, Levy

    2013-01-01

    The last decade has seen tremendous change in the commercial news media that play a central role in political processes in democracies around the world, as well as considerable progress in cross-national comparative media research. But despite the impact of Daniel C. Hallin and Paolo Mancini’s book......-conceptions, and of news content). In this piece, we call for further institutionally and system-oriented mixed-methods comparative research to advance our understanding of how current changes are impacting journalism, the news media, and ultimately politics in different settings. We suggest that existing conceptions...... Comparing Media Systems, empirical research into the institutional and systemic preconditions of journalism and news production has not kept pace with the rapid changes in the media, nor with the advances made in other areas of comparative media research (such as studies of news media use, journalists’ role...

  13. Climate change versus deforestation: Implications for tree species distribution in the dry forests of southern Ecuador

    Science.gov (United States)

    Hildebrandt, Patrick; Cueva, Jorge; Espinosa, Carlos Iván; Stimm, Bernd; Günter, Sven

    2017-01-01

    Seasonally dry forests in the neotropics are heavily threatened by a combination of human disturbances and climate change; however, the severity of these threats is seldom contrasted. This study aims to quantify and compare the effects of deforestation and climate change on the natural spatial ranges of 17 characteristic tree species of southern Ecuador dry deciduous forests, which are heavily fragmented and support high levels of endemism as part of the Tumbesian ecoregion. We used 660 plant records to generate species distribution models and land-cover data to project species ranges for two time frames: a simulated deforestation scenario from 2008 to 2014 with native forest to anthropogenic land-use conversion, and an extreme climate change scenario (CCSM4.0, RCP 8.5) for 2050, which assumed zero change from human activities. To assess both potential threats, we compared the estimated annual rates of species loss (i.e., range shifts) affecting each species. Deforestation loss for all species averaged approximately 71 km2/year, while potential climate-attributed loss was almost 21 km2/year. Moreover, annual area loss rates due to deforestation were significantly higher than those attributed to climate-change (P < 0.01). However, projections into the future scenario show evidence of diverging displacement patterns, indicating the potential formation of novel ecosystems, which is consistent with other species assemblage predictions as result of climate change. Furthermore, we provide recommendations for management and conservation, prioritizing the most threatened species such as Albizia multiflora, Ceiba trichistandra, and Cochlospermum vitifolium. PMID:29267357

  14. Climate change versus deforestation: Implications for tree species distribution in the dry forests of southern Ecuador.

    Science.gov (United States)

    Manchego, Carlos E; Hildebrandt, Patrick; Cueva, Jorge; Espinosa, Carlos Iván; Stimm, Bernd; Günter, Sven

    2017-01-01

    Seasonally dry forests in the neotropics are heavily threatened by a combination of human disturbances and climate change; however, the severity of these threats is seldom contrasted. This study aims to quantify and compare the effects of deforestation and climate change on the natural spatial ranges of 17 characteristic tree species of southern Ecuador dry deciduous forests, which are heavily fragmented and support high levels of endemism as part of the Tumbesian ecoregion. We used 660 plant records to generate species distribution models and land-cover data to project species ranges for two time frames: a simulated deforestation scenario from 2008 to 2014 with native forest to anthropogenic land-use conversion, and an extreme climate change scenario (CCSM4.0, RCP 8.5) for 2050, which assumed zero change from human activities. To assess both potential threats, we compared the estimated annual rates of species loss (i.e., range shifts) affecting each species. Deforestation loss for all species averaged approximately 71 km2/year, while potential climate-attributed loss was almost 21 km2/year. Moreover, annual area loss rates due to deforestation were significantly higher than those attributed to climate-change (P < 0.01). However, projections into the future scenario show evidence of diverging displacement patterns, indicating the potential formation of novel ecosystems, which is consistent with other species assemblage predictions as result of climate change. Furthermore, we provide recommendations for management and conservation, prioritizing the most threatened species such as Albizia multiflora, Ceiba trichistandra, and Cochlospermum vitifolium.

  15. Implications of climate change on hydrological extremes in the Blue Nile basin: A review

    Directory of Open Access Journals (Sweden)

    Meron Teferi Taye

    2015-09-01

    New hydrological insights: The review illustrates some discrepancy among research outputs. For the historical context, this is partially related to the period and length of data analyzed and the failure to consider the influence of multi-decadal oscillations. Consequently, we show that annual cycle of Blue Nile flow has not changed in the past five decades. For the future context, discrepancy is partially attributable to the various and differing climate and hydrological models included and the downscaling techniques applied. The need to prudently consider sources of uncertainty and potential causes of bias in historical trend and climate change impact research is highlighted.

  16. Effects of sex change on the implications of marine reserves for fisheries.

    Science.gov (United States)

    Chan, Neil C S; Connolly, Sean R; Mapstone, Bruce D

    2012-04-01

    Marine reserves have become widely used in biodiversity conservation and are increasingly proposed as fisheries management tools. Previous modeling studies have found that reserves may increase or decrease yields, depending on local environmental conditions and on the specific life-history traits of the fishery species. Sex-changing (female-to-male) fish are targets of some of the most important commercial and recreational fisheries in the world. The potential for disproportionate removal of the larger, older sex of such species requires new theory to facilitate our understanding of how reserves will affect the yields of surrounding fisheries, relative to fishes with separate sexes. We investigated this question by modeling the effects of marine reserves on a non-sex-changing and a sex-changing population. We used demographic parameter estimates for the common coral trout as a baseline, and we conducted extensive sensitivity analyses to determine how sustainable yields of sex-changing species are likely to be affected by reserves across a broad range of life-history parameters. Our findings indicate that fisheries for sex-changing species are unlikely to receive the same yield-enhancing benefit that non-sex-changing fisheries enjoy from marine reserves, and that often reserves tend to reduce sustainable yields for a given overall population size. Specifically, the increased egg production and high fertilization success within reserves is more than offset by the reduced egg production and fertilization success in the fished areas, relative to a system in which fishing mortality is distributed more evenly over the entire system. A key reason for this appears to be that fertilization success is reduced, on average, when males are unevenly distributed among subpopulations, as is the case when reserves are present. These findings suggests that, for sex-changing populations, reserves are more suited to rebuilding overfished populations and sustaining fishery viability

  17. Implications of environmental change for biosphere modelling: work for UK Nirex Ltd

    International Nuclear Information System (INIS)

    Thorne, M.C.

    1990-01-01

    Over the timescales of interest in deep geological disposal of radioactive wastes, climate is expected to change radically, with glacial/interglacial cycling anticipated. Climatic conditions and climate change have a influence on the characteristics of the biosphere into which the radionuclides emerge and on the doses to man which may occur. The various factors involved have been taken into account in assessment studies undertaken by the Nirex Disposal Safety Assessment Team. Results from these studies illustrate the major importance of dispersion processes in the biosphere in determining individual radiation doses, and the importance of using self-consistent patterns of human behaviour appropriate to the environment under consideration. 5 refs., 1 tab

  18. Downscaled climate change projections over northeastern South Africa: Implications for streamflow

    CSIR Research Space (South Africa)

    Mkhwanazi, M

    2015-09-01

    Full Text Available health, agriculture and biodiversity. A comprehensive assessment and understanding of the long-term impacts of climate change on water resources is therefore vital. This information, if applied in planning processes and decision making can... of Working Group II to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change [Barros, V.R., Field, C.B., Dokken, D.J., Mastrandrea, M.D., Mach, K.J., Bilir, T.E., Chatterjee, M., Ebi, K.L., Estrada, Y.O., Genova, R.C., Girma, B...

  19. The hydraulic permeability of blood clots as a function of fibrin and platelet density.

    Science.gov (United States)

    Wufsus, A R; Macera, N E; Neeves, K B

    2013-04-16

    Interstitial fluid flow within blood clots is a biophysical mechanism that regulates clot growth and dissolution. Assuming that a clot can be modeled as a porous medium, the physical property that dictates interstitial fluid flow is the hydraulic permeability. The objective of this study was to bound the possible values of the hydraulic permeability in clots formed in vivo and present relationships that can be used to estimate clot permeability as a function of composition. A series of clots with known densities of fibrin and platelets, the two major components of a clot, were formed under static conditions. The permeability was calculated by measuring the interstitial fluid velocity through the clots at a constant pressure gradient. Fibrin gels formed with a fiber volume fraction of 0.02-0.54 had permeabilities of 1.2 × 10(-1)-1.5 × 10(-4)μm(2). Platelet-rich clots with a platelet volume fraction of 0.01-0.61 and a fibrin volume fraction of 0.03 had permeabilities over a range of 1.1 × 10(-2)-1.5 × 10(-5)μm(2). The permeability of fibrin gels and of clots with platelet volume fraction of platelet volume fraction of >0.2 were modeled as a Brinkman medium of coarse solids (platelets) embedded in a mesh of fine fibers (fibrin). Our data suggest that the permeability of clots formed in vivo can vary by up to five orders of magnitude, with pore sizes that range from 4 to 350 nm. These findings have important implications for the transport of coagulation zymogens/enzymes in the interstitial spaces during clot formation, as well as the design of fibrinolytic drug delivery strategies. Copyright © 2013 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  20. Investigation on the Permeability Evolution of Gypsum Interlayer Under High Temperature and Triaxial Pressure

    Science.gov (United States)

    Tao, Meng; Yechao, You; Jie, Chen; Yaoqing, Hu

    2017-08-01

    The permeability of the surrounding rock is a critical parameter for the designing and assessment of radioactive waste disposal repositories in the rock salt. Generally, in the locations that are chosen for radioactive waste storage, the bedded rock salt is a sedimentary rock that contains NaCl and Na2SO4. Most likely, there are also layers of gypsum ( {CaSO}_{ 4} \\cdot 2 {H}_{ 2} {O)} present in the salt deposit. Radioactive wastes emit a large amount of heat and hydrogen during the process of disposal, which may result in thermal damage of the surrounding rocks and cause a great change in their permeability and tightness. Therefore, it is necessary to investigate the permeability evolution of the gypsum interlayer under high temperature and high pressure in order to evaluate the tightness and security of the nuclear waste repositories in bedded rock salt. In this study, a self-designed rock triaxial testing system by which high temperature and pressure can be applied is used; the μCT225kVFCB micro-CT system is also employed to investigate the permeability and microstructure of gypsum specimens under a constant hydrostatic pressure of 25 MPa, an increasing temperature (ranging from 20 to 650 °C), and a variable inlet gas pressure (1, 2, 4, 6 MPa). The experimental results show: (a) the maximum permeability measured during the whole experiment is less than 10-17 m2, which indicates that the gypsum interlayer has low permeability under high temperature and pressure that meet the requirements for radioactive waste repository. (b) Under the same temperature, the permeability of the gypsum specimen decreases at the beginning and then increases as the pore pressure elevates. When the inlet gas pressure is between 0 and 2 MPa, the Klinkenberg effect is very pronounced. Then, as the pore pressure increases, the movement behavior of gas molecules gradually changes from free motion to forced directional motion. So the role of free movement of gas molecules gradually

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