bluuebunny/crossref_metadata_2025 huggingface dataset:
Binding of estrogen receptor α/β heterodimers to chromatin in MCF-7 cells
Authors: Papoutsi Zoi , Zhao Chunyan , Putnik Milica , Gustafsson Jan-Åke , Dahlman-Wright Karin
Published: April 2009

Estrogen receptors (ERs), ERα and ERβ, belong to a group of transcription factors that, upon ligand binding, regulate gene expression by binding to specific DNA regions in chromatin as dimers. In this article, we applied the sequential chromatin immunoprecipitation assay (Re-ChIP) to study the simultaneous presence of ERα and ERβ on various DNA-binding regions in intact chromatin. ERα/β heterodimers were isolated by precipitation with anti-ERβ antibody followed by anti-ERα antibody from a stable MCF-7-derived cell line that expresses endogenous ERα and an inducible version of ERβ. The Re-ChIP method was first validated based on the detection of ERα/β heterodimers bound to a promoter region of the pS2 gene known to bind both ERα and ERβ. We next examined 12 ER-binding sites using Re-ChIP assays for ERα/β heterodimer recruitment. Our results confirmed the recruitment of ERα/β heterodimers to all these regions. This study represents the first demonstration of binding of ERα/β heterodimers to various DNA-binding regions in intact chromatin.
Influence of axial load on lateral pile response in liquefiable soils. Part I: physical modelling
Authors: KNAPPETT J.A. , MADABHUSHI S.P.G.
Published: April 2009

Current research work into the behaviour of piled foundations in liquefiable soils has concentrated on the response to lateral inertial and kinematic loads. It has recently been demonstrated in the literature, however, that an alternative mechanism exists, whereby piles carrying significant axial loads may become unstable as lateral soil restraint is lost owing to earthquake-induced soil liquefaction. In the work presented here and in a companion paper, this effect is examined in greater depth, particularly regarding the integration with and effects on the lateral response of piles such that the two effects can be treated under a unified framework. Dynamic centrifuge testing was used to investigate pile instability by examining the behaviour of pile groups with lateral deflections. Amplification of these deflections was observed to occur during liquefaction, although currently available simple idealisations of soil behaviour were found greatly to over-predict these amplifications when compared with the experimental observations. The response of the soil to such large-deformation events was determined for use in more sophisticated numerical modelling presented in the companion paper. Relative pile–soil flexibility was found to have a strong influence on amplifications occurring in the tests. Ultimately, at high axial load or amplification, unstable collapse (bifurcation) was found to occur both during earthquake shaking, and afterwards owing to excess pore pressure migration altering the strength of the supporting soil surrounding the piles.
Long‐Term Observations of Vadose Zone and Groundwater Nitrate Concentrations under Irrigated Agriculture
Authors: Derby Nathan E. , Casey Francis X. M. , Knighton Raymond E.
Published: April 2009

Proper N management for agricultural production is critical to minimize groundwater contamination with NO3For 18 yr, research was conducted to observe NO3–N concentrations in the vadose zone, groundwater, and subsurface drainage under sprinkler‐irrigated, primarily corn (Zea maysL.) production. Potato (Solanum tuberosumL.) and soybean [Glycine max(L.) Merr.] were also grown intermittently on the site. The lysimeter leachate NO3–N concentration increased to 156 mg L−1under corn production within 1 yr after the initiation of irrigation (at the onset of the study), then decreased to <10 mg L−1during a 6‐yr period of best‐management N fertility management for corn. The average yearly lysimeter NO3–N concentration fluctuated between 8 and 117 mg L−1during the study. Nitrate concentrations in the shallow groundwater followed a similar time series trend as leachate concentrations, but with lower concentrations and lagging about 1 yr. Subsurface drainage NO3–N concentrations were much lower but followed the same trend as the shallow groundwater. An N balance indicated higher net N mineralization after the initiation of irrigation and the years after potato production. Fertilizer N application rates and yearly weather conditions, which affected crop vigor and N uptake, combined to affect the fall residual soil NO3Fall soil NO3from 0‐ to 1.8‐m depth was the most significant factor influencing the leachate NO3–N concentration each year during the study (r2= 0.76).
Effective Soil Hydraulic Parameters for Transient Flows in Heterogeneous Soils
Authors: Zhu Jianting , Sun Dongmin
Published: April 2009

This study investigated the use of effective soil hydraulic properties (expressed in terms of hydraulic parameters) applicable to large‐scale transient infiltration problems in a landscape with horizontally heterogeneous soil hydraulic properties. The heterogeneous landscape was conceptualized as an equivalent homogeneous medium with effective hydraulic properties. The main objectives were to investigate: (i) which effective soil hydraulic property schemes are suitable to represent average behavior of large‐scale infiltration processes, (ii) how the effective hydraulic parameters are sensitive to the process time frame, and (iii) how hydraulic parameter variability and correlation impact the effective hydraulic parameters. The heterogeneous landscape was represented by a series of vertically homogeneous stream tubes or parallel columns. Large‐scale average infiltration behavior in the heterogeneous soils was quantified through Monte Carlo simulations of multiple realizations (stream tubes) of local‐scale infiltration. The optimal effective hydraulic parameters were then calculated with an inverse procedure that minimized the difference between average cumulative infiltration and cumulative infiltration based on a single set of effective parameters. Three scenarios were used to optimize either two hydraulic parameters simultaneously or only one hydraulic parameter while using the arithmetic mean for the other parameter. Results indicate that while the effective hydraulic parameters could simulate average infiltration more closely when multiple parameters were optimized together, the effective parameter values were more variable as time evolved. Optimizing only one hydraulic parameter while keeping the arithmetic mean for the other parameter produced more uniform effective hydraulic parameters with time, but this approach did not represent average infiltration behavior of the heterogeneous soils as well as when multiple hydraulic parameters were optimized simultaneously.
Experimental Study of Gas Transport Parameters in Unsaturated Silica Flour
Authors: Fen Chiu-Shia , Huang Yunkuen , Chen Jiann-Long
Published: April 2009

An experimental study was conducted to assess the relative contributions of molecular and Knudsen diffusions for gas‐phase transport in unsaturated silica flour with an intrinsic permeability of 1 ∼ 2 × 10−14 m2 Single‐gas phase flow and binary diffusion experiments were performed on the same soils to determine the Knudsen diffusion and the effective gas‐phase diffusion coefficients, respectively. These results were further used to assess the diffusibility factor for Fick's law of diffusion and the obstruction factor for the Dusty Gas Model theory. These factors were used to account for impedance to gas diffusion caused by the tortuous nature of soil pores. The Knudsen diffusion coefficient was found to be one to two orders of magnitude greater than the effective diffusion coefficient for silica flour at water saturations ranging from 53 to 75% (v/v), which suggested that the Knudsen effect has negligible impact on the effective diffusion coefficient for the unsaturated silica‐flour system at water saturations lower than 75%. For unsaturated silica flour with air‐filled porosity <0.2, the diffusibility factor (or the obstruction factor) value can be more than 10 times smaller than the values estimated by other diffusibility correlations published in the literature.
Fractal Analyses of Steady Infiltration and Terrain on an Undulating Agricultural Field
Authors: Green Timothy R. , Dunn Gale H. , Erskine Robert H. , Salas Jose D. , Ahuja Lajpat R.
Published: April 2009

Analysis of spatially distributed quasi‐steady infiltration measurements is important because of the effects of infiltration capacity on spatial patterns of soil water, nutrients, and plant development and production. We explored fractal models of quasi‐steady infiltration rates, emphasizing apparent changes in scaling exponents with domain size. Quasi‐steady infiltration rates were measured using single‐ring (0.30‐m‐diameter) constant‐head infiltrometers at 150 locations over 10 landscape positions (30 by 30 m, or approximately 0.1 ha) across a field (approximately 100 ha). At each landscape position, 15 rings were distributed randomly in nested patterns. The field in northeastern Colorado comprises undulating agricultural terrain cropped with dryland winter wheat (Triticum aestivum L.) under conventional tillage. Data were analyzed for multifractal and monofractal behavior. A monofractal model fit the infiltration data best, while terrain attributes other than elevation deviated from monofractals to different degrees. The Hurst exponent (H) was estimated by fitting power‐law variograms at different scales across the field. Values of H changed with the maximum lag distance, peaking near H = 0.9 at approximately 200 m, which represents a typical hillslope length. Spatial persistence in steady infiltration was not observed at long distances (>300 m). Using dense and sparsely sampled terrain attributes as proxy data indicated that the observed spatial scaling of infiltration was not solely due to the clustering of infiltration measurements. These results shed new light on research needed to address spatial variability of soil hydraulic properties, with implications for hillslope process interactions between land areas when modeling distributed infiltration, runoff and run‐on, and plant water use.
Saturation Kinetics of a Vertical Multilayer Hydraulic Sealing System Exposed to Rock Salt Brine
Authors: Emmerich Katja , Kemper Gerhard , Königer Franz , Schlaeger Stefan , Gruner Matthias , Gaßner Wolfgang , Hofmann Martin , Nüesch Rolf , Schuhmann Rainer
Published: April 2009

Transport of rock salt brine through a vertical multilayer hydraulic sealing system (HTV‐1) was examined during the saturation process. The HTV‐1 was a semi‐technical‐scale experiment that simulated a shaft sealing. Multilayer drift and shaft sealings are part of the multibarrier system in geologic repositories for hazardous or radioactive waste. In contrast to the usual sealing constructions, the examined system combines sealing bentonite layers (DS) with equipotential layers (ES) of higher hydraulic conductivity that are expected to prevent inhomogeneous liquid transport in barriers independent of the surrounding host rock and formation water. Rock salt brine (density 1.15 g/mL = 4 mol/L) was chosen to simulate natural brines. It was forced through the column with a solution pressure up to 9.3 MPa. No artificial saturation was applied in advance of brine inflow. The experiment was terminated after 1 yr after the brine passed two DS and two ES and reached the upper DS. A detailed snapshot analysis of water and salt distribution and layer geometry was obtained. The salt/water ratio of the initial brine was 0.26 and was evenly detected within the wet ES as well as the wet DS. Thus, the results revealed the functionality of the sandwich‐like sealing system. Natural Ca‐ and Mg‐rich bentonite was partially transformed into its Na‐saturated form depending on exposure time to the brine, but high salt concentration did not prevent swelling. Swelling of the lower bentonite layers caused compaction of the upper bentonite layers, as it was confined from the bottom and by jacket friction.
Surface and Interfacial Properties of Nonaqueous‐Phase Liquid Mixtures Released to the Subsurface at the Hanford Site
Authors: Nellis Scott R. , Yoon Hongkyu , Werth Charles J. , Oostrom Mart , Valocchi Albert J.
Published: April 2009

Surface and interfacial tensions are key parameters affecting nonaqueous‐phase liquid (NAPL) movement and redistribution in the subsurface after spill events. In this study, the impact of major additive components on surface and interfacial tensions for organic mixtures and wastewater was investigated. Organic mixture and wastewater compositions were based on CCl4 mixtures released at the U.S. Department of Energy's Hanford site, where CCl4 was discharged simultaneously with dibutyl butyl phosphonate, tributyl phosphate, dibutyl phosphate, and a machining lard oil. A considerable amount of wastewater consisting primarily of nitrates and metal salts was also discharged. The measured tension values revealed that the addition of these additive components caused a significant lowering of the interfacial tension with water or wastewater and the surface tension of the wastewater phase in equilibrium with the organic mixtures, compared with pure CCl4, but had minimal effect on the surface tension of the NAPL itself. These results led to large differences in spreading coefficients for several mixtures, where the additives caused both a higher (more spreading) initial spreading coefficient and a lower (less spreading) equilibrium spreading coefficient. This indicates that if these mixtures migrate into uncontaminated areas, they will tend to spread quickly but will form a higher residual NAPL saturation after equilibrium than pure CCl4 With time, CCl4 probably volatilizes more rapidly than other components in the originally disposed mixtures and the lard oil and phosphates would become more concentrated in the remaining NAPL, resulting in a lower interfacial tension for the mixture. These results show that the behavior of organic chemical mixtures should be accounted for in flow and transport models.
An Efficient Lumped Mixed Hybrid Finite Element Formulation for Variably Saturated Groundwater Flow
Authors: Belfort Benjamin , Ramasomanana Fanilo , Younes Anis , Lehmann François
Published: April 2009

Accurate numerical simulation of infiltration in the vadose zone remains a challenge, especially when very sharp fronts are modeled. In this work, we used the mixed hybrid finite element (MHFE) method, which allows a simultaneous approximation of both pressure head and velocity and can handle general irregular grids with highly heterogeneous permeability. For many problems dealing with unsaturated water flow, however, the MHFE solutions exhibit significant unphysical oscillations. To avoid this phenomenon, we developed an efficient mass‐lumping scheme with the MHFE method for solving the mixed form of the Richards equation. In this work, the standard and lumped MHFE formulations were compared and the ability of the lumped formulation to reduce unphysical oscillations was determined for one‐ and two‐dimensional infiltration problems. Theoretical analysis based on the M‐matrix property, which guarantees the discrete maximum principle, and practical test cases performed in this study underline the advantage of using an acute triangulation to completely remove the unphysical oscillations. Indeed, contrary to the standard approach, the lumped formulation satisfies the M‐matrix property without any constraint on the time step size to be used.
A New Coaxial Time Domain Reflectometry Probe for Water Content Measurement in Forest Floor Litter
Authors: Canone D. , Previati M. , Ferraris S. , Haverkamp R.
Published: April 2009

Knowledge of water content is important for water resources management and risk prevention. For areas covered with forest, the presence of decomposed or undecomposed forest litter poses a real problem for the monitoring of volumetric water content. Traditional methods such as time domain reflectometry (TDR) are difficult to apply, as the inconsistence of the porous material often leads to density modifications close to the probe wires. The aim of this work was to develop a TDR probe that can be used for loose materials while ensuring optimum working conditions in terms of ease of insertion into the porous medium, contact with the surrounding porous medium, and homogeneity and confinement of electrical energy storage. The performance of the new probe was tested on three porous media: a sandy soil and decomposed and undecomposed litter taken from four different sources of forest material. A classical TDR three‐rod probe and a coaxial probe were used for comparison. Permittivity data were analyzed with parameters related to either mineral or organic media and two physically based models. The comparison of the results necessary for the evaluation of the probe performance was performed using the criterion of mean absolute error and the associated standard deviation, calculated on the difference between the water content values measured by the TDR probes and those determined by gravimetric observations. For the sandy soil, the new probe gave results comparable to those of the coaxial probe but more accurate than those obtained with the three‐rod probe. For the forest litter samples, the new probe systematically gave the most accurate results. Once calibrated, the new probe allows measuring volumetric water content in forest litter within an error range of 0.02 m3/m3.
Steady-State Characteristic Study for Integration of DFIG Wind Turbines into Transmission Grid
Authors: Li Shuhui , Haskew Timothy A. , Challoo Rajab
Published: April 2009

Wind power has emerged as a promising renewable energy resource. A wind power plant, normally located in an area with reliably favorable wind speed, is connected to the grid through a transmission line. This paper presents a steady-state characteristic study of a DFIG-based wind energy conversion system (WECS) that is integrated into the power grid through a transmission system. Steady-state models in a d-q reference frame are developed for a single wind turbine, a simplified wind power plant, and an integrated WECS and grid system. In addition, a transient simulation system is built to validate the accurateness of the steady-state results by using MatLab SimPowerSystems. An integrative study is performed to investigate WECS parametric data simultaneously as the number of DFIG wind turbines connected to a wind farm changes under constant turbine driving torque and driving power conditions. Parallel and series compensations, usually used to improve WECS performance, are investigated. A comparative study is presented to illustrate the characteristic difference between WECSs using fixed-speed induction generators and variable-speed DFIGs.
Breeding and Non‐Breeding Survival of Lesser Prairie‐Chickens Tympanuchus pallidicinctus in Texas, USA
Authors: Lyons Eddie K. , Collier Bret A. , Silvy Nova J. , Lopez Roel R. , Toole Benjamin E. , Jones Ryan S. , DeMaso Stephen J.
Published: April 2009

Lesser prairie‐chickens Tympanuchus pallidicinctus have declined throughout their range because of loss or fragmentation of habitat from conversion of native prairie to agricultural cropland, exacerbated by overgrazing and drought. We used data from radio‐marked lesser prairie‐chickens to determine whether differences in survival existed between populations occurring in two areas dominated by different vegetation types (sand sagebrush Artemisia filifolia vs shinnery oak Quercus havardii) in the Texas Panhandle from 2001 through 2005. We used a model‐selection approach to evaluate potential generalities in lesser prairie‐chicken survival. Our results indicated that survival of lesser prairie‐chickens differed between breeding and non‐breeding periods, and between study populations. We estimated annual survival of lesser prairie‐chickens at 0.52 (95% CI: 0.32–0.71) in the sand sagebrush and 0.31 (95% CI: 0.12–0.58) in the shinnery oak vegetation type. Our results suggest that demographic differences in lesser prairie‐chicken within sand sagebrush and shinnery oak vegetation types throughout the Texas Panhandle should be evaluated, especially during the breeding season. Based on our results, higher mortality of birds during the breeding season illustrates the need to manage for vegetation components such as sand sagebrush and residual bunchgrasses as opposed to shinnery oak such that potential breeding season mortality may be lessened.
A Critical Assessment of Public Consultations on GMOs in the European Union
Authors: Ahteensuu Marko , Siipi Helena
Published: April 2009

The paper highlights shortcomings in the public consultation practices on the deliberate release and placing on the market of GMOs in the European Union and in one of its member countries, Finland. It is argued that current GMO consultation practices do not meet the aims and objectives on which their introduction is typically justified. Specifically, they do not serve democracy, increase consensus, enable better decisions to be made, or establish trust. We conclude that there is a clear need for the active development of the GMO consultation practices and for a further critical discussion on the ethical and socio-political foundation of public engagement.
Evaluating the ‘Ethical Matrix’ as a Radioactive Waste Management Deliberative Decision-Support Tool
Authors: Cotton Matthew
Published: April 2009

UK radioactive waste management policy making is currently taking place within a participatory and analytic-deliberative decision-making framework; one that seeks to integrate public and stakeholder values and perspectives with scientific and technical expertise. One important aspect of this socio-technical reframing of the radioactive waste problem is an explicit recognition that legitimate and defensible policy making must take into account important ethical issues if it is to be a success. Thus, there is a need for tools to incorporate adequate assessment of ethical issues in a way that is compatible with this approach. The ‘ethical matrix’ is one such tool used recently to address a range of agricultural and natural resource issues that shows promise for this field. This paper assesses the strengths and limitations of the matrix and outlines a framework for the development of alternative tools to better satisfy the needs of ethical assessment in radioactive waste management decision-making processes.
Environmental Policy with Integrity: A Lesson from the Discursive Dilemma
Authors: Shockley Kenneth
Published: April 2009

In response to what has been called the discursive dilemma, Christian List has argued that the nature of the public agenda facing deliberative bodies indicates the appropriate form of decision procedure or deliberative process. In this paper I consider the particular case of environmental policy where we are faced with pressures not only from deliberators and stakeholders, but also in response to dynamic changes in the environment itself. As a consequence of this dilemma I argue that insofar as the focus of a policy forming body is on the formation of viable environmental policy, rather than on a set of pre-existent ideological commitments, deliberative agents should be responsive as a unified body to the pressures of precedent, the best available science, and their own best individual judgments. In the case of environmental policy the dilemma pressures deliberative bodies to display what Ronald Dworkin has called integrity even in cases where this requires those deliberative bodies to sacrifice being maximally responsive to the preferences of individual deliberators.
Darwinian Humanism and the End of Nature
Authors: Kirkman Robert
Published: April 2009

Darwinian humanism proposes that environmental philosophers pursue their work in full recognition of an irreducible ambiguity at the heart of human experience: we may legitimately regard moral action as fully free and fully natural at the same time, since neither perspective can be taken as the whole truth. A serious objection to this proposal holds that freedom and nature may be unified as an organic whole, and their unity posited as a matter of substantive truth, by appeal to teleology. In particular, I consider Hegel's account of the emergence of Absolute Spirit, weigh its advantages and disadvantages as an approach to human moral experience and as a strategic move for environmentalists, and conclude with a refinement of Darwinian humanism and a clarification of its implications for environmental ethics.
Sludge on Tap: Queensland's First Water Pollution Legislation, 1944-1985
Authors: Wegner Jan
Published: April 2009

Before the environmental movement of the 1960s and 1970s, controls on water pollution in Australia were piecemeal, scattered through a number of Acts. These often regulated pollution by compromises with the polluters, rather than preventing it outright, unless a threat to public health could be proved. This situation characterised the first Act written specifically to control water pollution in the Australian state of Queensland, sparked by the pollution of the Herbert River with tin dredge effluent after 1944. Conditions imposed on the dredge operations were compromises, chosen for their utility for dredging rather than their effectiveness, and further legislation maintained the situation so that pollution of the river and water supplies drawn from it continued for 40 years. The Act, and the pollution episode which sparked it, are an example of a theme noticeable in some pre-1970s pollution cases: controls were imposed that were cheap to implement or useful to the polluting agency, but which were ineffective in stopping pollution outright. Unfortunately, in Queensland, that attitude persisted after other jurisdictions had moved to more environmentally sensitive styles of pollution management.
Book Reviews
Authors: Robin Libby , Cooper Tim , Goodall Heather , Balzaretti Ross , Van Dam Petra J.E.M. , Collier Peter
Published: April 2009

I.G. Simmons, Global Environmental History 10,000 BC to AD 2000 (LIBBY ROBIN)
William Beinart and Lotte Hughes, Environment and Empire (TIM COOPER)
Gunnel Cederloef, Landscapes and the Law: Environmental Politics, Regional Histories and Contests over Nature (HEATHER GOODALL)
Roberta Cevasco, Memoria verde. Nuovi spazi per la geografia (ROSS BALZARETTI)
Marnie Leybourne and Andrea Gaynor, eds., Water. Histories, Cultures, Ecologies (PETRA J.E.M. VAN DAM)
Dennis Cosgrove, Geography and Vision: Seeing, Imagining and Representing the World (PETER COLLIER)
A method for comprehending and adapting complex supply chains in agriculture
Authors: Archer A. Ainsley , Higgins Andrew , Thorburn Peter
Published: April 2009

Success stories for applying supply chain methods to enhance agricultural industries are limited, despite their great potential. One key reason is that agricultural chains are subjected to the considerable managerial, social and biophysical complexity, which often leads to the inappropriate use of different methods. We capture supply chain complexity by formulating a matrix of biophysical by management factors. This is used to comprehend supply chain complexity and show how participants in agricultural chains can implement adaptation strategies that add value to their industry. Through various case studies we illustrate how adaptation strategies adopted by chain participants relate to different quadrants of the complexity matrix. An analysis of the literature based on this matrix also shows the suitability of different types of technical methods when used within adaptation strategies of each matrix quadrant. The complexity matrix aids the identification of the right strategies to use for the right problem through engagement with the right people.
An integrated model of buyer-seller relationship performance in agribusiness: the partial least squares approach
Authors: Gyau Amos , Spiller Achim
Published: April 2009

In this paper, we provide an integrated model for the business relationship performance between Ghanaian exporters and European importers of fresh fruit and vegetables. Twelve hypotheses, which explore the relationships between various dimensions of inter-firm relationship performance and its antecedents are formulated and tested based on 101 interviews with fresh fruit and vegetable exporters in Ghana. Using the Partial Least Squares statistical technique, ten out of the twelve hypotheses formulated were supported. The results of the study confirm most of the findings from previous studies on the subject, while new insights on the relationship between the variables used in the study are also revealed. We conclude that an integrated model, which combines both the financial and the non-financial relationship performance dimensions can provide a more realistic understanding of the relationship between the exporters and the importers than partial models which may conceal the effects of the relationships between the former and the latter.
El trabajo intelectual en el entorno digital: nuevas formas de escritura y de erudición
Authors: González Quirós José Luis
Published: April 2009

El entorno digital constituye el nuevo escenario en que se ha de desarrollar la investigación, la lectura y la escritura en el futuro. Su naturaleza, profundamente distinta de la que es propia del entorno que se creó con la imprenta, modificará con toda seguridad las formas de trabajo de los autores y estudiosos, las prácticas intelectuales y la manera en la que se argumentan las distintas exposiciones. La escritura y la lectura son actividades humanas que, debido a su ejercicio ya inmemorial, nos han hecho olvidar su condición de invento, de tecnologías, simples pero nada naturales ni espontáneas, como lo prueba el hecho del mucho tiempo que hay que dedicarles en la educación. El entorno digital nos dota, a la vez, de un nuevo escritorio y de un nuevo mercado: aunque aún es pronto para verlo, se están creando nuevas formas de autoría, de escritura y de erudición digital.
Ciberciudadanía, cultura y bienes públicos
Authors: Álvarez J. Francisco
Published: April 2009

La sociedad red transforma la vida cotidiana, las diversas manifestaciones culturales, los negocios, las esferas más diversas de la vida privada y social. La forma en que se generan los bienes públicos en la red exige una preocupación explícita por la libertad de acceso y la generación de nuevos servicios, que ayuden a superar limitaciones de los individuos y faciliten desdibujar las diversas brechas digitales y ciberculturales. El gobierno electrónico resulta culturalmente decisivo en esta fase de expansión de la cibersociedad. Las tecnologías amplían las capacidades humanas, expanden el espacio y las formas de acción social, incluidas la producción y gestión cultural. También producen cambios en las formas de generación, reproducción y transmisión del conocimiento (social).
Interdisciplinariedad y redes epistemológicas de la ciencia en Internet
Authors: Gherab Martín Karim
Published: April 2009

Se caracteriza la expresión ciencia abierta, relacionándola con el acceso abierto, y se muestra el modo en que un buen diseño de los repositorios digitales y de sus interconexiones en Internet pueden incrementar sensiblemente la interdisciplinariedad. Además, dichos repositorios se caracterizan como trading zones o “mercados académicos”, de donde las revistas académicas podrían recuperar artículos que deberían presentar en forma de discursos unitarios, en el contexto de un modelo propuesto radicalmente diferente a las prácticas editoriales comunes actualmente.
Las alteraciones silíceas de las lavas de Montaña Señalo, erupción de Timanfaya (1730-1736) (Lanzarote, Islas Canarias)
Authors: Carmona J. , Romero C. , Dóniz J. , García A.
Published: April 2009

La presencia de alteraciones de origen hidrotermal entre las lavas de la erupción de Timanfaya (1730-36), con altas proporciones del cuarzo y ópalo, indica la circulación efectiva de fluidos calientes. El origen de estos fluidos estaría en zonas profundas por debajo de la isla, donde se produciría la disolución de la sílice a partir de areniscas y radiolaritas, movilizándose de esta manera este componente hacia la superficie en forma de coloides de Si(OH)4. El estudio en profundidad del ópalo indica la presencia de fases tipo A-inicio de CT y C. Si se tiene en cuenta el tiempo en el que se producen estas transformaciones en la evolución diagenética de esta fase amorfa (10.000-50.000 años), indicaría la presencia de un proceso acelerador que podría estar relacionado con una importante circulación de fluidos o con procesos de alteración meteórica, capaces de producir estas transformaciones en unas lavas de menos de 300 años.
Explosives
Authors: Boileau Jacques , Fauquignon Claude , Hueber Bernard , Meyer Hans H.
Published: April 2009

The article contains sections titled:1.Introduction2.Physical Properties and Chemical Reactions2.1.Detonation2.1.1.Ideal Detonation2.1.2.Deflagration and Detonation2.2.Prediction of Detonation Data2.2.1.Complete Calculation2.2.2.Approximation Methods2.3.Nonideal Detonation Waves and Explosives2.3.1.Nonideal Explosive Compositions2.3.2.Detonation of Cylindrical Cartridges2.3.3.Low‐ and High‐Order Detonation Velocity2.3.4.The Effect of Confinement2.4.The Buildup of Detonation2.4.1.Combustion – Deflagration – Detonation Transition (DDT)2.4.2.Shock‐to‐Detonation Transition (SDT)2.4.3.Shock and Impact Sensitivity2.5.Classification of Explosives2.6.Functional Groups2.6.1.Nitro Group2.6.2.Other Groups3.Application3.1.Energy Transfer from the Explosive to the Surroundings3.1.1.Shock and Blast Waves3.1.2.Casing and Liner Acceleration3.2.High Compression of Solids3.3.Metal Forming and Welding3.4.Rock Blasting3.5.Perforators, Shaped or Hollow Charges4.Primary Explosives5.Secondary Explosives5.1.Production5.2.Specific Secondary Explosives5.2.1.Nitrate Esters5.2.2.Aromatic Nitro Compounds5.2.3.N‐Nitro Derivatives6.High Explosive Mixtures6.1.Desensitized Explosives6.2.TNT Mixtures6.3.Plastic‐Bonded Explosives (PBX)7.Industrial Explosives7.1.Dynamites7.2.Ammonium Nitrate Explosives (Ammonites)7.3.Ammonium Nitrate/Fuel Oil Explosives (ANFO/ANC Explosives)7.4.Slurries and Water Gels7.5.Emulsion Explosives7.6.Uses8.Test Methods8.1.Performance Tests8.2.Safety9.Legal Aspects and Production9.1.Safety Regulations9.2.Production of Military Explosives10.Toxicology and Occupational Health
Isolation and Differentiation of Xenopus Animal Cap Cells
Authors: Ariizumi Takashi , Takahashi Shuji , Chan Te‐chuan , Ito Yuzuru , Michiue Tatsuo , Asashima Makoto
Published: April 2009

Xenopus is used as a model animal for investigating the inductive events and organogenesis that occur during early vertebrate development. Given that they are easy to obtain in high numbers and are relatively large in size, Xenopus embryos are excellent specimens for performing manipulations such as microinjection and microsurgery. The animal cap, which is the area around the animal pole of the blastula, is destined to form the ectoderm during normal development. However, these cells retain pluripotentiality and upon exposure to specific inducers, the animal cap can differentiate into neural, mesodermal, and endodermal tissues. In this sense, the cells of the animal cap are equivalent to mammalian embryonic stem cells. In this unit, the isolation and differentiation of animal cap cells, the so‐called animal cap assay, is described. Useful methods for analyzing the mechanism of animal cap differentiation at the molecular level are also described. Curr. Protoc. Stem Cell Biol. 9:1D.5.1‐1D.5.31. © 2009 by John Wiley & Sons, Inc.
Contingent Behaviours
Authors: Addington Michelle
Published: April 2009

Michelle Addington questions the accepted Modernist conception of the interior as a hermetically sealed envelope. She highlights the vicissitudes in attitudes that have existed over time to interior and exterior conditions by flagging up the 19th‐century pursuit of ventilation and the permeable outside wall, which was pursued in the quest for public sanitation and a misguided belief in the ‘toxic’ interior. Copyright © 2009 John Wiley & Sons, Ltd.
99.7 Per Cent Pure
Authors: White Mason
Published: April 2009

The HEPA air filter is only capable of processing 99.7 per cent of airborne particles, leaving 0.3 per cent unaccounted for. Mason White describes the work of Canadian installation artist An Te Liu who made air‐filtration appliances his main subject. Copyright © 2009 John Wiley & Sons, Ltd.
Domestic Micro‐Environments
Authors: Lehanneur Mathieu
Published: April 2009

In the following works, Mathieu Lehanneur readdresses our understanding of domestic spaces through the environmental systems that control and condition them. Such spaces are generally conditioned by centralised heating, cooling and ventilation systems that lump together many sensory qualities, including primary thermal controls as well as by‐products of scent and sound, into a singular, mechanical system that fails to engage any of them fully. Lehanneur's projects look to separate these senses into systems distributed throughout the home, engaging each one specifically and locally, in an attempt to redefine the domestic spaces they are located within. Copyright © 2009 John Wiley & Sons, Ltd.
When Cold Air Sleeps
Authors: Lally Sean
Published: April 2009

Our cities today can be read off in binary contrast, as a ‘figure‐ground’ of conditioned and unconditioned spaces. What, however, if we stopped regarding the outside as something to be tempered or mediated? Guest‐editor Sean Lally of WEATHERS explains how for his practice climatic conditions open up new potential for organisational and spatial design. Copyright © 2009 John Wiley & Sons, Ltd.
Kings Place: Hall One
Authors: Watson Howard
Published: April 2009

When is an office development more than office space? Howard Watson describes how through the inclusion of two small auditoria in the basement of Kings Place in London King's Cross, Dixon Jones was able to create a true mixture of amenities while responding to the area's cultural needs and eclipsing its reputation for being less than salubrious. Copyright © 2009 John Wiley & Sons, Ltd.
Weisz + Yoes (WXY architecture + urban design)
Authors: Merkel Jayne
Published: April 2009

Few small avant‐garde practices have an impact on visitors to New York like that of WXY, as the firm is sometimes called. Theirs is particularly surprising since, as Jayne Merkel notes, they have only completed a handful of freestanding buildings. But this mid‐career husband‐and‐wife team of Claire Weisz and Mark Yoes ‐ and their new partner, Layng Pew, whom they met at Yale 20 years ago ‐ are changing the face of Times Square and redesigning historic Battery Park at the southern tip of Manhattan where ferries leave for the Statue of Liberty and Ellis Island. These heavily used public places are only the most recent ones that they have inventively improved over the last decade and a half. Copyright © 2009 John Wiley & Sons, Ltd.
Articulating Environmental Grounds
Authors: de Beaurecueil Anne Save , Lee Franklin
Published: April 2009

A new generation of thinking is emerging in the manipulation of ground systems that, with the aid of parametrics, is enabling a new level of design precision and ecological calibration. Anne Save de Beaurecueil and Franklin Lee describe how with Diploma Unit 2 at the Architectural Association in London, they are working towards their goal of fusing architecture, landscape and contemporary art through an engagement with articulated ground organisations. Copyright © 2009 John Wiley & Sons, Ltd.
Architecture of Disbelief: Is Architectural Speciation a Good Thing?
Authors: Spiller Neil
Published: April 2009

Can visionary architects have their cake and eat it, luxuriating in pecuniary success while also continuing to assert their avant‐gardism? Neil Spiller attended a conference in Cornell that brought the role of the architectural visionary under the spotlight and gave him much food for thought. Copyright © 2009 John Wiley & Sons, Ltd.
Bioluminescence and Nanoluminescence
Authors: Yeang Ken
Published: April 2009

Electricity's reliance on coal‐fired power stations and other limited mineral and petroleum resources makes finding an alternative energy source for lighting buildings' interiors and our external spaces one of the greatest challenges of the 21st century. Ken Yeang finds some clues for its resolution in existing biological and evolving artificial systems. Copyright © 2009 John Wiley & Sons, Ltd.
An Unconventional Low‐Cost Museum
Authors: Croci Valentina
Published: April 2009

Valentina Croci describes how a diminutive museum dedicated to the feminine arts in Salerno, southern Italy, provides an intimate experience for visitors: its modest interior being enriched by an interface of information panels and interactive installations designed by Id‐Lab in Milan. Copyright © 2009 John Wiley & Sons, Ltd.
Tower Houses of Sana'a
Authors: Firley Eric
Published: April 2009

Eric Firley, the co‐author of a new compendium The Urban Housing Handbook, which investigates 30 major housing types from around the world, describes one of the most intriguing examples, situated in the Yemen on the Arabian Peninsula. Copyright © 2009 John Wiley & Sons, Ltd.
Controllable Molecular Doping and Charge Transport in Solution‐Processed Polymer Semiconducting Layers
Authors: Zhang Yuan , de Boer Bert , Blom Paul W. M.
Published: April 2009

Here, controlled p‐type doping of poly(2‐methoxy‐5‐(2′‐ethylhexyloxy)‐p‐phenylene vinylene) (MEH‐PPV) deposited from solution using tetrafluoro‐tetracyanoquinodimethane (F4‐TCNQ) as a dopant is presented. By using a co‐solvent, aggregation in solution can be prevented and doped films can be deposited. Upon doping the current–voltage characteristics of MEH‐PPV‐based hole‐only devices are increased by several orders of magnitude and a clear Ohmic behavior is observed at low bias. Taking the density dependence of the hole mobility into account the free hole concentration due to doping can be derived. It is found that a molar doping ratio of 1 F4‐TCNQ dopant per 600 repeat units of MEH‐PPV leads to a free carrier density of 4 × 1022 m−3. Neglecting the density‐dependent mobility would lead to an overestimation of the free hole density by an order of magnitude. The free hole densities are further confirmed by impedance measurements on Schottky diodes based on F4‐TCNQ doped MEH‐PPV and a silver electrode.
Tissue Engineering Using Laminar Cellular Assemblies
Authors: Yang Joseph , Yamato Masayuki , Sekine Hidekazu , Sekiya Sachiko , Tsuda Yukiko , Ohashi Kazuo , Shimizu Tatsuya , Okano Teruo
Published: April 2009

As proposed in the late 1980s by Langer and Vacanti, the ultimate goal of tissue engineering is the development of structures that can be used to treat or replace damaged or diseased organs and tissues. For the regeneration of various organs such as the heart, liver, and kidney, the development of adequate vascular networks within the engineered tissues remains a significant obstacle in the formation of cell‐dense structures that resemble the native parenchyma. While tissue engineering using biodegradable scaffolds has been successful in the re‐creation of tissues where extracellular matrix is abundant, we have developed cell‐sheet‐based tissue engineering for the construction of tissues using laminar assemblies of cells harvested from temperature‐responsive culture dishes. Using cell sheet engineering, we present new strategies for the development of organ‐like tissue structures containing well‐organized vascular networks.
Diffusion through ordered force fields in nanopores represented by Smoluchowski equation
Authors: Wang Fu Yang , Zhu Zhong Hua , Rudolph Victor
Published: April 2009

The classical Einstein or Fick diffusion equation was developed in random force fields. When the equation is applied to gas transport through coal, significant discrepancies are observed between experimental and simulation results. The explanation may be that the random force field assumption is violated. In this article, we analyze molecular transport driven by both random and ordered (directional) forces in nanopores. When applied to CO2 transport through cone‐shaped carbon nano‐tubes (CNTs) and Li+ doped graphite pores, computational results show that directional force fields may significantly affect porous media flow. Directional forces may be generated by potential gradients arising from a range of non‐uniform characteristics, such as variations in the pore‐sizes and in local surface compositions. On the basis of the simulation and experimental results, the Smoluchowski and Fokker‐Planck equations, which account for the directional force fields, are recommended for diffusion through ordered force fields in nanopores. © 2009 American Institute of Chemical Engineers AIChE J, 2009
Synthesis and characterization of cobalt nano‐particles through microwave polyol process
Authors: Cheng Wen‐Tung , Cheng Huei Wen
Published: April 2009

This article aims to synthesize and character cobalt nano‐particles through microwave polyol process. At first, cobalt acetate is used as precursor to synthesize cobalt nano‐particles by microwave assisted ethylene glycol in the presence of polyvinylpyrrolidone (PVP) as capping agent. As measured from ion‐coupled plasma (ICP) and thermo‐gravimetric analysis (TGA), the yields of as‐synthesized cobalt particles in average diameters of 40 and 81 nm verified by transmission electronic microscopy (TEM), are 71 and 85%, respectively; and the structure of as‐synthesized cobalt nano‐particle is a face‐center cubic structure analyzed by X‐ray diffraction (XRD). Finally, the as‐synthesized cobalt nano‐particle modified by oleic acid is dispersed in kerosene to character magnetic property. As measured by vibration sample magnetometer (VSM), the saturation magnetisms of cobalt nano‐particles with average diameters of 40 and 81 nm are 39.1 and 29.5 emu/g, respectively, in solution. © 2009 American Institute of Chemical Engineers AIChE J, 2009
A simple model for vapor‐moisture equilibrium in biomass subtrates
Authors: Vásquez V. R. , Coronella C. J.
Published: April 2009

Equilibrium moisture content (EMC) plays a fundamental role on the properties of bioderived solids such as food, waste biomass, seeds, and many others. For foods, the moisture content affects flavor, texture, and the way the food is stored. In other applications, moisture affects drying conditions and energy requirements for biomass processing. Adequate modeling of EMC in biomass as a function of the water activity is very important in many engineering applications. Most models used to correlate EMC with water activity are based on traditional adsorption models which take into account the adsorption energy of water with the substrate only and do not consider other nonadsorption interactions of water within the substrate such as mixing and swelling effects. Many other models are empirical, which are commonly used for interpolation. Although a detailed description of this type of substrate is very complex, we present a simple model based on standard molecular‐thermodynamic models and standard statistical mechanics formulations to correlate the EMC with water activity that attempts to consider both adsorption and nonadsorption interactions of the water with the substrate. Although the model is basic, it captures the behavior of water in this type of systems fairly well and it can be used to fit experimental data with parameters that provide better physical insight on the nature of system. We suggest how to improve the model fundamentally if better knowledge of the water interactions in the substrate are available. © 2009 American Institute of Chemical Engineers AIChE J, 2009