bluuebunny/crossref_metadata_2025 huggingface dataset:
Factors that Control the Range and Variability of Amorphous Silica in Soils in the Hubbard Brook Experimental Forest
Authors: Saccone Loredana , Conley Daniel J. , Likens Gene E. , Bailey Scott W. , Buso Donald C. , Johnson Chris E.
Published: October 2008

In terrestrial ecosystems, the largest pool of amorphous silica (ASi) is stored in soils and is an important reservoir of biologically active Si for the global biogeochemical cycling of Si. Only limited data are available that quantify the size of this reservoir and often these estimates are made from the physical separation of silt‐sized phytoliths, which can underestimate the ASi pool. Soil samples from five watersheds in a temperate‐zone continental ecosystem at the Hubbard Brook Experimental Forest, New Hampshire, were analyzed for ASi using alkaline digestion. Soils from two of the watersheds were analyzed after experimental forest removal. In undisturbed watersheds, ASi was concentrated at the surface of the soil profile, similar to organic matter, and then progressively decreased with depth. This investigation supports our hypothesis that forest disturbance leads to redistribution of Si in the soil. In fact, although deforestation led to significant decreases in ASi in the upper soil horizons, total profile ASi (∼17,400 kg SiO2 ha−1) remained essentially unchanged, implying translocation downward. Significant increases in the transport of dissolved silica (DSi) by rivers have been observed with deforestation, however, in which the ASi pool in soils may play an important role. Additional studies should target the potential role of ASi as a buffer for DSi losses from deforested watersheds.
Estimating Forest Soil Carbon and Nitrogen Stocks with Double Sampling for Stratification
Authors: Shaw C. H. , Boyle J. R. , Omule A. Y.
Published: October 2008

Precise and accurate estimation of C and N in forest soils is important for monitoring long‐term site productivity and C stock changes. Obtaining such estimates remains a major challenge, however, especially because of high natural variability in the forest floor. Although most researchers have used simple random sampling (SRS) for within‐plot soil sampling, double sampling for stratification (DSS) can be used to decrease costs, increase precision, and increase power. Estimates of C and N stocks based on DSS were compared with those estimated by SRS in the humus forms of Douglas‐fir [Pseudotsuga menziesii(Mirb.) Franco] stands in the Cascade Mountains of Oregon. Generally, DSS was 1.34 to 5.11 times more efficient than SRS for total C, and 1.07 to 2.00 for total N. Coefficients of variation estimated from DSS were about one‐half of those estimated by SRS and reported elsewhere in the literature. The cost for sampling using DSS was one‐third to one‐half of that for SRS, depending on the number of strata used. Costs were reduced because fewer samples were required using DSS to provide the same precision as SRS. The DSS design was more powerful than SRS and could detect smaller changes than SRS with the same number of samples. Results suggested that the most efficient design for total C would use two strata where samples were allocated proportional to variance rather than proportional to area. Overall, large gains in efficiency can be realized with a more complex within‐plot sampling design, i.e., DSS, compared with SRS.
Surfactant‐Induced Unsaturated Flow: Instrumented Horizontal Flow Experiment and Hysteretic Modeling
Authors: Bashir Rashid , Smith James E. , Stolle Dieter F.
Published: October 2008

Organic compounds with surface‐active properties reduce the surface tension of water and can change soil water contact angles depending on their aqueous concentration. The presence of such compounds in the unsaturated zone affects soil moisture characteristics and unsaturated hydraulic conductivity relations, and can cause flow as a result of induced soil water pressure gradients. Some studies have used horizontal column experiments to measure the surfactant‐driven movement of water in unsaturated media; however, they have all used destructive sampling methods to determine water contents and did not measure soil water pressures. We attempted to gain better insight into this unsaturated soil water flow process through continual monitoring of water contents with time domain reflectometry and soil water pressures with pressure transducer equipped tensiometers. One half of the horizontal one‐dimensional flow cell was prewetted (but unsaturated) with water while the other half contained the same fluid content of 7% butanol solution. The temporal and spatial water content and soil water pressure information improved our understanding of the surfactant‐induced flow, including perturbations associated with solute gradients. Backflow in the flow cell was observed at later times as the water‐content‐induced component of the hydraulic gradients became more important. Hysteretic numerical simulations of the one‐dimensional horizontal flow cell using a modified version of HYDRUS 5.0 including coupled flow and transport through concentration‐dependent surface tensions were performed for the case in which butanol is the surface‐active compound. The numerical simulations, which used independently measured flow and transport parameters, provided a good fit to the experimental data and provided further insight into the induced flow behaviors.
Ammonia Volatilization from Urea‐Based Fertilizers Applied to Tall Fescue Pastures in Georgia, USA
Authors: Vaio Nicolas , Cabrera Miguel L. , Kissel D.E. , Rema John A. , Newsome J. Frank , Calvert Vaughn H.
Published: October 2008

The use of urea fertilizers in grasslands is likely to increase in areas with concentrated animal feeding operations as restrictions on manure applications are implemented. Concerns have been raised about the economic and environmental impacts of NH3 loss from these urea fertilizers. This study evaluated NH3 losses from Nitamin (a urea polymer), urea–NH4NO3 (UAN), and granular urea applied to tall fescue (Festuca arundinacea Schreb.) plots at 50 kg N ha−1 in fall and spring for 2 yr. Fertilizers were applied to circular plots (30‐m diameter) and NH3 loss was measured by the modified passive flux method for 69 to 120 d after application. In a separate laboratory study, Nitamin, UAN, and urea were surfaced applied to fescue thatch at 100 kg N ha−1 and treatments were incubated at 24°C and 90% relative humidity for 31 d. In fall applications, urea lost more NH3 (19% in 2004, 46% in 2005) than UAN or Nitamin, which were not different from each other (6% in 2004, 34% in 2005). In contrast, there were no differences among fertilizers in spring applications, with average losses of 13% in 2005 and 17% in 2006. In the laboratory study, urea lost significantly more NH3 (24%) than UAN or Nitamin, which were not different from each other (average 9% loss). These results indicate that Nitamin and UAN undergo similar NH3 losses, and that both fertilizers may lose less NH3 than urea under conditions favorable to volatilization.
Evaluation of Three Models that Describe Soil Water Retention Curves from Saturation to Oven Dryness
Authors: Lu Sen , Ren Tusheng , Gong Yuanshi , Horton Robert
Published: October 2008

Measuring a soil water retention curve (SWRC) with the pressure plate device is generally limited to matric suctions ≤1500 kPa. A few models have been proposed to describe the SWRC from saturation to oven dryness using measurements in the pressure plate matric suction range. The development and validation of these models were mostly based on a limited set of published measurements, and in general, the models have not been validated by independent data from additional soils. In this study, we tested the hypothesis that these models were able to predict the complete SWRC from a limited range of water retention data or by using water retention parameters available from the literature. Soil water retention measurements from saturation to oven dryness were conducted on disturbed, repacked soil samples of various textures using the pressure plate method and the dew point potential technique. When the model parameters were obtained from water retention data in the 0 to 1500 kPa range, the RMSE of water content was approximately 0.01. The RMSE of the Fayer–Simmons model was slightly larger than that of the Webb model and Khlosi model. In addition, the Fayer–Simmons model was sensitive to the data point near the matric suction of 1500 kPa. The Khlosi model produced acceptable results if data sets from 0 to 500 kPa were used for model establishment; larger errors were observed on some soils if the measured data were limited to the 0‐ to 100‐kPa range. All three models could provide reliable results across the entire range of soil water content if measurements in the 0‐ to 1500‐kPa range were available.
Controls on the Sorption, Desorption and Mineralization of Low‐Molecular‐Weight Organic Acids in Variable‐Charge Soils
Authors: Strahm Brian D. , Harrison Robert B.
Published: October 2008

Understanding the controls on interactions between soluble organic compounds and the solid soil matrix is important in understanding soil organic matter dynamics in general, including specific impacts on pedogenic processes, nutrient bioavailability, and C sequestration. This study investigated the pH‐dependent relationship between low‐molecular‐weight organic acids (LMWOAs) and variable‐charge soils as a control on the retention of an otherwise highly mobile and bioavailable class of organic compounds. Sorption isotherms of three LMWOAs (one amino acid [glycine], one monocarboxylic acid [propionic acid], and one dicarboxylic acid [malonic acid]) were generated for three forest soils using batch equilibration techniques. Before equilibration, soils were saturated with KCl to control for competing ions, and both soils and solutions were adjusted to one of three pH levels (4.0, 6.0, or 8.0 ± 0.1). Bioavailability was assessed by generating desorption isotherms for each LMWOA–pH combination as well as through laboratory incubations for mineralization rates. Results indicate that sorption of the three LMWOAs followed the general trend: malonic acid ≫ glycine > propionic acid. Sorption tended to increase with acidity and short‐range‐ordered aluminosilicate content, and was correlated (r = 0.69, P < 0.001) with the magnitude of the difference between the positive charge on the mineral surface and the negative charge of the LMWOA. This trend remained true for the amino acid, which demonstrated sorptive maximums that were more strongly correlated with anion exchange (r = 0.62, P = 0.1) than cation exchange (r = 0.05, P = 0.9). These observations, coupled with decreased desorption and lower mineralization rates at lower pH levels, suggest the potential for an electrostatic mechanism to contribute to the abiotic retention of organic matter in variable‐charge soils under acidic conditions.
Impacts of Harvest Residue Management on Soil Carbon Stocks in a Plantation Forest
Authors: Jones Haydon S. , Garrett Loretta G. , Beets Peter N. , Kimberley Mark O. , Oliver Graeme R.
Published: October 2008

The impacts of plantation forest management on soil C stocks in New Zealand need to be better understood for the purposes of C accounting under the Kyoto Protocol. We investigated the impacts of three harvest residue management treatments on C and N stocks in a scoriaceous forest soil: whole‐tree harvesting plus forest floor removal, whole‐tree harvesting, and stem‐only harvesting. Volumetric samples were collected from the forest floor and three mineral soil depth increments (0–0.1, 0.1–0.2, and 0.2–0.3 m) 16 to 17 yr after harvesting. Both fine (<2‐mm) and coarse (>2‐mm) fractions of the mineral soil were analyzed. No significant impacts on stocks of C and N were observed in the mineral soil fine fraction. Averaged across treatments, the 0‐ to 0.3‐m mineral soil coarse fraction contained 5.2 ± 0.52 Mg C ha−1, representing 25% of total mineral soil C, with most derived from the fine‐earth‐coated scoria gravel. The inclusion of the coarse fraction stocks enabled the detection of significant treatment effects. Stem‐only harvesting (residue retention) had significantly larger C stocks in the 0‐ to 0.1‐m total mineral soil (fine + coarse fractions), forest floor, and total soil (forest floor + 0–0.3‐m total mineral soil) pools than whole‐tree harvesting (residue removal) plus forest floor removal. We recommend the retention of both harvest residues and forest floor materials for the maintenance of soil C stocks in plantation forests. Detection of residue management impacts on C stocks in soils with vesicular gravels may require analysis of the coarse fraction.
Wetting Rate and Rain Depth Effects on Crust Strength and Micromorphology
Authors: Fan Y. , Lei T. , Shainberg I. , Cai Q.
Published: October 2008

Aggregate disintegration and crust formation at soil surfaces exposed to rain are caused by rapid wetting of the dry aggregates and by raindrop impact. The relative importance of these two mechanisms was evaluated by studying the effects of the wetting rate (WR) and raindrop impact on crust strength and crust micromorphology. Two soils, a loess (Typic Haplustalf) and a black soil (Pachic Udic Argiboroll), varying in their organic matter content (15.2 and 42.6 g kg−1, respectively) and aggregate stabilities, were packed in splash cups, prewetted at WRs of 2 or 50 mm h−1, and exposed to 5 to 60 mm of simulated rainfall. For the unstable loess soil, crust strength increased and crust microfabric deteriorated with increases in cumulative rainfall but were unaffected by the WR. Conversely, in the black soil with high aggregate stability, changes in crust strength and crust microfabric were affected by the WR; for the slow WR, both phenomena were largely unaffected by increases in cumulative rainfall but, for the faster WR, the phenomena were greatly affected by rain depth and crust formation proceeded rapidly. Both WR and raindrop impacts affect surface aggregate breakdown and crust formation. The energy released by slaking while wetting dry aggregates is, however, considerably higher than that of raindrop impact. Thus, the relative importance of WR and rain depth depends on the stability of the soil aggregates. For soils with stable aggregates, raindrop impact alone is not sufficient to destroy aggregates and form crusts. Rapid wetting of the dry soil is essential for aggregate breakdown and crust formation. For soils with unstable aggregates, the energy of raindrop impact is sufficient for seal formation.
A Method for Measuring Saturated Hydraulic Conductivity in Anisotropic Soils
Authors: Iwanek Małgorzata
Published: October 2008

Saturated hydraulic conductivity (Ks) is an important soil parameter that is difficult to measure, especially in an anisotropic medium. Many methods for determining Ks have been developed over time, but taking different water flow directions into consideration is possible in only a few of them; furthermore, these few methods cannot be universally applied. The method proposed here allows Ks to be determined in both anisotropic and heterogeneous soils. It involves testing cubic soil cores using the Wit apparatus. To use this permeameter for samples that are not cylindrical in shape, it is necessary to prepare special measurement equipment. One such set of equipment developed consists of the soil cube (four sides of which are sealed with gypsum), which is placed in a protective box and connected to a measurement cuboid. In the soil sample, water always flows from the bottom up during the test, but it is possible to turn the sample over and thus analyze different water flow directions. The soil cubes needed are small (0.05 by 0.05 by 0.05 m), but for a particular set of conditions only 15 cores extracted from each sampling location was found to be enough to determine Ks with a precision of ±15%. Results yielded by the presented method appeared to be comparable with Ks values obtained using a constant‐head permeameter with cylindrical soil cores. The advantages of the proposed technique are the possibility of measuring Ks in both horizontal and vertical directions using the same sample, a lack of leakage along the edges of a sample, the ease of soil sample extraction, and the technique's use of inexpensive materials.
Validity of the Centrifuge Method for Determining the Water Retention Properties of Tropical Soils
Authors: Reatto Adriana , da Silva Euzebio Medrado , Bruand Ary , Martins Eder Souza , Lima Jorge Enoch Furquim Werneck
Published: October 2008

This study compared the centrifuge and pressure plate methods with appropriate run durations. Samples collected in tropical soils located in Brazil along a 10‐km local hydrosequence across the Cerrado–Amazonia transition (Set 1) and along a 350‐km regional toposequence across the Cerrado region (Set 2) were selected to compare and discuss statistically the similarity of the soil water retention recorded by using the pressure plate and centrifuge methods. The results showed good agreement (R2= 0.99) for the 1:1 comparison of measured pointwise soil water content values (Set 1) as well as for the fitted soil water content curves by the van Genuchten model using data points obtained with the two methods (Set 2). Thus, the centrifuge method should be considered as an appropriate method for determining soil water retention properties not only because of similar results with the pressure plate method but also because it is much less time consuming.
Adsorption of Trihydroxamate and Catecholate Siderophores on α‐Iron (Hydr)oxides and their Dissolution at pH 3.0 to 6.0
Authors: Cervini-Silva Javiera
Published: October 2008

The adsorption of desferrioxamine (DFOB), acetyl desferrioxamine (DFOD1), and a catecholate derivative (DFOMTA)] on goethite (α‐FeOOH) and hematite (α‐Fe2O3) and mineral dissolution behavior at pH 3.0 to 6.0 were studied to yield an understanding of the mechanisms of siderophore complexation on α phases and also to study how variations in siderophore molecular structure, as modified by proton activity, affect siderophore effectiveness at releasing Fe from different soil minerals. Wet‐chemistry experiments were conducted to react 1 g L−1goethite or hematite with 240 μmol L−1siderophores. Iron release values were found to be as high as 350 ± 20 μmol L−1, with no evidence of mineral transformation as determined by x‐ray diffraction analyses. The proton activity strongly influenced Fe release, but no correlations between Fe concentrations and pH were found. The siderophore molecular structure influenced Fe release; the effectiveness for releasing Fe decreased in the order DFOMTA > DFOD1 > DFOB. Kinetics and Fe siderophore stability constants in solution data trends correlated possibly because the formation of Fe–siderophore complexes limits dissolution for both α‐phase trihydroxamate and catecholate siderophores. Incongruency between dissolution kinetics and siderophore adsorption data trends was explained by siderophores triggering dissolution mechanisms that may not require surface adsorption. It is plausible then that the mineralogical composition of the soil could, in part, regulate the production of siderophores by microorganisms and plants. Based on Fe release data for hematite, it was concluded that siderophores contribute to the Fe pool in soil solutions with decreasing proton activity. Thus, the role of siderophores in releasing structural Fe becomes increasingly important as mineral solubility becomes limiting. By contrast, based on Fe release for goethite, the contribution of siderophores to the acquisition of Fe in goethitic soil profiles becomes less pronounced with decreases in the proton activity of the soil solution.
Soil Organic Matter Quality under Different Land Uses in a Mountain Watershed of Nepal
Authors: Shrestha Bharat Man , Certini Giacomo , Forte Claudia , Singh Bal Ram
Published: October 2008

Land use change is one of the anthropogenic interventions that may induce substantial modifications to both the quantity and quality of soil organic matter (SOM). Soils from three cultivated areas (two types of rainfed upland and one irrigated lowland) and two forests (subtropical managed and temperate unmanaged) in a midhill watershed of Nepal were studied to assess the effect of land use change on SOM quality. Bulk SOM was analyzed using solid‐state13C nuclear magnetic resonance (NMR) and fractionated by acid hydrolysis into pools with different chemical composition and, thus, different tendencies to decomposition. The NMR analysis showed a clear prevalence of O‐alkyl C over alkyl C and aromatic C, with major differences between both soils and two depth intervals of the same soil (0–20 and 20–40 cm). Acid hydrolysis revealed that the labile C pool is larger in the 0‐ to 20‐ than the 20‐ to 40‐cm soil depth of each land use. Labile C was larger in the temperate unmanaged forest and the irrigated cultivated land than in the other soils at both soil depths. Of the cultivated rainfed soils, the recently reclaimed soil contained less labile C than the historically cultivated soil, while the labile C in the irrigated soil exceeded that in both rainfed soils. The results suggest that changes in land use from forest to cultivation and the irrigation of the cultivated land may significantly affect not only the quantity but also the quality of the SOM and, more importantly, its chemical recalcitrance to degradation. As a consequence, any future decisions regarding land management in the fragile mountain areas of Nepal should be carefully considered with respect to the nature of the SOM.
Small‐Increment Electric Soil Sampler
Authors: Wuest Stewart B. , Schillinger William F.
Published: October 2008

Measurement of soil bulk density and volumetric water content in small (≤2‐cm) depth increments is tedious and time consuming. Most methods require compositing several subsamples to control measurement error, and few are feasible with loose, dry soils. We developed and tested a sampler that uses an electric linear actuator to push an intact soil core out of the sampling tube. The soil core is maintained in an upright position and protected from fracturing by remaining inside the tube until sectioned with a cutting saw. Precise length increments and flat cuts are easily obtained, even in loose soils. Compared with existing incremental sampling technology developed 30 yr ago, the electric sampler reduced sample variability by half. The electric sampler requires only 7 min to collect a 26‐cm core and section it into 2‐cm increments, compared with 20 min per core with the older sampler.
High Coupling Efficiency in 2D Guided-Wave Photonic Band Gap Extended Microcavities for Sensing Applications
Authors: Ciminelli Caterina , De La Rue Richard M. , Armenise Mario N.
Published: October 2008

Label-free techniques for sensing are of great interest for identification of molecules on a functional surface. Currently, a growing research activity dealing with optical approaches does contribute to the development of new devices. A remarkable advance in the field of bio-detection is given by the use of photonic crystals enabling to design and fabricate high-sensitivity and compact novel optical sensors. Many photonic crystal sensors on several different materials have been proposed in literature. However, further improvement of the sensitivity requires an additional research effort on the optimization of both the design and fabrication process. In this paper we report on the solution of the mode-mismatch occurring at the input and output interfaces of the microcavity. Mode-mismatch is responsible for the increase of the scattering and degradation of transmission characteristics of the photonic crystal. Optimization of the sensor design can be achieved by using an appropriate tapering of some hole rows into reflectors. Numerical results have proved that two physical effects occur simultaneously, i.e. conventional tapering which is dominant at high resonant wavelengths, and resonant conditions of the external cavity, when the radius of the holes in the external row is greater than that of the internal one. This last effect is more clear at low wavelength.
New Trends in Fiber-Optic Chemical and Biological Sensors
Authors: Orellana Guillermo , Haigh David
Published: October 2008

The most relevant contributions in the field of fiber-optic chemical sensors and biosensors in the last five years are reviewed. Gas optodes (including oxygen, hydrogen, carbon dioxide and ammonia), humidity sensors, monitors for pH, cations and anions, and sensors for organic compounds constitute the different sections. Optical fiber biosensors based on enzymes, antibodies, nucleic acids and whole microorganisms serve to illustrate the state-of-the-art in this active area. Selected examples of absorbance-based, luminescent, evanescent wave, Fabry-Perot, chemiluminescent and surface plasmon resonance-based sensors and biosensors, among other techniques used for interrogate the sensitive part of the devices, are described.
Fiber Optic Sensors for Biomedical Applications
Authors: Baldini Francesco , Giannetti Ambra , Mencaglia Andrea A. , Trono Cosimo
Published: October 2008

Biomedicine is surely the area where the optical fibre sensors can play an important role. Thanks to their potential miniaturisation and their easy handling they are offering unique performances in invasive or minimally invasive applications. The immunity to electromagnetic interference and the absence of electrical contact make the optical fibres useful also in the case of non invasive applications for the setting of the interrogation optoelectronic unit in a safer location, keeping only the sensing element close to the patients bedside. As a matter of fact, there are many optical fibre sensors designed for biomedical applications and described in the literature, but the greater part of them stops at the prototype level, without entering the hospital. The clinical validation, which is the necessary step after the characterisation of the laboratory prototype, is often an insurmountable obstacle due to the requirements of compliance with the European Directives on Medical Devices or with the regulations of the Food and Drug Administration. The strategy followed for the clinical validation in the case of optical fibre sensors developed at the Institute of Applied Physics for the detection of bile-containing refluxes, gastric carbon dioxide and interstitial pH is described. An example for potential non-invasive applications in point of care testing is also given with a novel optical platform for the interrogation of optical biochips.
Scattered Colorimetry and Multivariate Data Processing as an Objective Tool for Liquid Classification and Mapping
Authors: Ciaccheri Leonardo , Mignani Anna G.
Published: October 2008

Scattered colorimetry, that is multi-angle and multi-wavelength absorption spectroscopy performed in the visible spectral range, provides an integrated and global measurement of the color and turbidity of liquids. By a multivariate processing of the spectral data, the liquids can be mapped, classified and compared according to their peculiar characteristics. Details of the instrumentation and data processing are given, and the results achieved by analyzing many different types of liquids such as extra-virgin olive oil, beer, detergent in water and lubricant oil, are presented.
Real-Time Monitoring of Siloxane Monolayer Film Formation on Silica Using a Fiber Bragg Grating
Authors: Stanford Christopher J. , Dagenais Mario , Park Ju-Hee , DeShong Philip
Published: October 2008

We present a series of experiments to study the silanization of the silica surface of a fiber Bragg grating biosensor. A simple 4-layer attachment model is developed to describe the bonding of 3-aminopropyl triethoxysilane (APTES) or 3-aminopropylethoxydimethylsilane (APMDS) to the silica surface when both APTES and APMDS are dissolved in water or in pure ethanol. An adsorbed water layer is created during the attachment of APTES and APMDS and is necessary to explain the results in water and in ethanol. It is found that a monolayer of APMDS attaches to the silica surface when APMDS is diluted in either water or ethanol. In the case of APTES, it is found that a 1-2 and 5 APTES layers attach to the glass surface when APTES is diluted in water and in ethanol, respectively.
Molecularly Imprinted Polymers as Selective Recognition Elements in Optical Sensing
Authors: Moreno-Bondi Maria C. , Navarro-Villoslada Fernando , Benito-Pena Elena , Urraca Javier L.
Published: October 2008

Molecular imprinted polymers (MIPs) are molecular recognition elements that can be tailored towards a wide variety of target molecules. These human-made materials are relatively easy to prepare and have found a broad application as substitutes of antibodies or enzymes. They have been successfully applied to the development of chromatographic or solid phase extraction methods and have attracted a great interest for the development of electrochemical, piezoelectrical or optical sensors. In parallel with the classification of biosensors, MIP-based devices can work according to two different detection schemes: affinity sensors (“plastic-bodies”) and catalytic sensors (“plastic-enzymes”). These devices can be interrogated using different optical techniques, such as fluorescence, light absorption (UV-Vis, Infrared) spectroscopy, chemiluminescence, surface plasmon resonance, or Raman scattering. This paper reviews the main developments and applications of MIPs in the area of optical sensors with special emphasis on their analytical applications.
Fiber-Optic Chemical Nanosensors by Electrostatic Molecular Self- Assembly
Authors: Villar Ignacio Del , Matias Ignacio R. , Arregui Francisco J.
Published: October 2008

A review of optical fiber sensors based on nanostructured coatings fabricated by means of the layer-by-layer electrostatic-self assembly (ESA) method is presented here. The modification of the optical properties of these sensing coatings by the target parameter can induce changes in the reflected or transmitted spectrum. This property can be exploited for the development of refractometers, pH sensors, chemical sensors, biosensors and other applications. In addition to the experiments performed, the theory of some of these phenomena have been also studied in order to understand the behavior of the sensors and to improve their sensing characteristics.
The Effects of an Imagery Intervention with Motivational General-Mastery Content upon Collective Efficacy Perceptions for a Novel Team Task
Authors: Shearer David A. , Mellalieu Stephen D. , Thomson Robert , Shearer Catherine
Published: October 2008

This study assessed the effects of an imagery intervention with motivational general-mastery (MG-M) content upon individual collective efficacy perceptions for a novel obstacle course task. Following an introductory orientation session participants ( n = 24) were allocated into teams of 3 and assigned to either an imagery ( n = 12) or control stretching intervention ( n = 12). Each participant completed a 6-week intervention program with weekly supervised sessions. Collective efficacy and task cohesion was measured during the baseline and post-intervention sessions using the Collective Efficacy Inventory (CEI) [1] and the task factors of the Group Environment Questionnaire (GEQ) [2]. A mixed 2 × 2 ANOVA determined a significant main effect within groups between the baseline and post intervention collective efficacy scores. Significant interactions between time and group were also observed for collective efficacy scores and both task components of the GEQ. The results provide initial support for the use of imagery interventions with MG-M content to enhance individual perceptions of collective efficacy.
An Investigation of Imaginary Companions in an Ethnic and Grade Diverse Sample
Authors: Mathur Ravisha , Smith Maureen C.
Published: October 2008

This investigation focused on the nature of imaginary companions (ICs) in 43 ethnically diverse, young school-age children (kindergarten, first, and second grade). We tested the hypotheses that our diverse sample would be able to describe their ICs in detail that is similar to rich descriptions of ICs found in samples of preschool-age, Caucasian children. Although we did not expect grade differences, we expected gender differences and explored differences by ethnicity. We also hypothesized that children with ICs would report greater tendencies to engage in overall fantasy play and that they would rate the importance of companionship with a real friend stronger than did children without an IC. The results supported the hypotheses that children in our sample would have ICs and be able to describe them in rich detail. The analyses revealed no grade or gender differences in having a companion, but did suggest that there may be subtle differences in the ICs of different ethnic groups that require further exploration. Finally, children with an IC did appear to have a greater fantasy orientation than children without an IC which suggests that the presence of ICs are an important part of children's lives from a wide range of backgrounds.
Experience in Imagery and Imagery Vividness
Authors: Campos Alfredo , Gómez-Juncal Rocío , Pérez-Fabello María José
Published: October 2008

The aim of this study was to assess the effects of experience in mental imagery, imagery type (normal, bizarre, or mixed), and the repetition of mental imagery formation on imagery vividness. Two experiments were carried out: Experiment 1 consisted of a sample of 152 Spanish compulsory secondary education students who were shown a list of 16 simple sentences describing normal, bizarre, or mixed normal and bizarre situations prior to rating their imagery vividness. The procedure was repeated with the same imagery after a 24-hour interval. Subjects were also asked about their experience in using mental imagery. Subjects with mental imagery experience rated imagery vividness higher than inexperienced subjects. Image vividness scores were higher after repeating imagery formation than in the first imagery vividness ratings. Mixed and bizarre imagery obtained higher imagery vividness scores than normal imagery. In Experiment 2 a sample of 146 students, of the same academic background as in Experiment 1, were shown a list of 16 complex sentences under the same experimental conditions. Significant differences in imagery vividness ratings were observed in terms of experience and repetition of imagery. Ratings were higher for experienced than inexperienced subjects, and in the second ratings following the repetition of imagery formation. No significant differences in imagery vividness ratings were observed between both experimental groups in terms of imagery type. The results are discussed in the context of previous studies, and new lines of research are proposed.
The Perceptual Arc: Unraveling the Mysteries of Perception
Authors: Brooks Eugene M.
Published: October 2008

Based in science, perception is viewed as an arc in which energies from objects in the environment are brought into the mind. Phenomenal objects are then “projected” as a purely mental process and perceived as being in the environment. The concept is supported by the writings of Locke and Kant. There are profound implications for the understanding of consciousness and subjective reality. In addition to the perceptual arc, there is brief peripheral discussion of the creation of qualities, synecdoche, and aspects of brain physiology leading to consciousness.
Occupational Medicine and the Construction of “Difficult Reputations”
Authors: Guidotti Tee L.
Published: October 2008

The creation of “difficult reputations” is a collective act of disparagement often undertaken to diminish the influence of the target individual or group for political reasons. This process can be observed in efforts to discredit the field of occupational medicine and the American College of Occupational and Environmental Medicine (ACOEM) by revising its history. Examples are given from Draper's The Company Doctor: Risk, Responsibility, and Corporate Professionalism and LaDou, in which new sources of historical information do not support the allegations or impressions conveyed. This tendency is inimical to progress in occupational health in general and may be highly destructive to the field if not recognized and discouraged.
Difficult Reputations and the Social Reality of Occupational Medicine
Authors: Draper Elaine
Published: October 2008

This response to Tee Guidotti's (2008) critique of Elaine Draper's The Company Doctor: Risk, Responsibility, and Corporate Professionalism (2003) argues that a forthright examination of the conflicts of those working in the field of occupational medicine is essential to maintaining the health of the profession and to promoting constructive policies. Research for The Company Doctor reveals how doctors walk a tightrope of professional demands on them. The author describes how corporate employment affects medicine and science and how professionals working in corporations are subject to the decisions of company managers and to economic and legal imperatives stemming from their status as corporate employees. Analyzing company doctors' role in confronting toxics and responding to liability fears in corporations, the author argues that problems of lost credibility, stigmatization, and tarnished reputation that company doctors describe largely stem from the organizational constraints, economic interests, and other aspects of the social context of their work. These social forces exert powerful pressure on the ethical framework and daily work lives of these professionals as well as on the reputation of their field. The author discusses ways in which the conflicting demands from being both a corporate employee and a physician are a social and structural problem beyond individual ethics.
Beyond Reputation: Debate on the Role of Corporate Influence in Occupational and Environmental Medicine
Authors: Bohme Susanna Rankin , Egilman David
Published: October 2008

In his article in this issue, Tee Guidotti casts recent works addressing corporate influence on occupational medicine as “collective act[s] of disparagement … undertaken … for political reasons.” We move beyond the question of reputation to address key conflicts in the history of occupational medicine, including the American Occupational Medical Association's historical role in weakening the beryllium standard and the American College of Occupational and Environmental Medicine's recent efforts to limit the extent of the Family Medical Leave Act. The corporate practice of externalizing health and safety costs makes industry influence an important ongoing topic of debate in occupational and environmental medicine.
“Guidotti Fails to Convince” on Two Issues
Authors: Lax Michael B.
Published: October 2008

This is a response to Tee Guidotti's defense of the American College of Occupational and Environmental Medicine (ACOEM) as an ally for workers struggling for safer and healthier work. Guidotti fails to convince on two central issues: a blindness to the powerful impact of corporate power on professional thought and behavior; and a lack of evidence that ACOEM has ever been inclined to collaborate with workers. In addition, Guidotti relies upon his own review of ACOEM's historical archive to support his argument. Unfortunately, access to this archive is limited to those deemed reliable by Guidotti, giving the appearance of an attempt to control both information and interpretation, and calling Guidotti's own “objectivity” into question.
Protecting Disaster Site, Support, and Recovery Workers
Authors: Celenza James
Published: October 2008

When a disaster strikes, FEMA activates the worker safety and health provisions (annex document) of the National Response Plan (NRP). The annex describes actions needed to ensure that threats to safety and health are recognized, evaluated, and controlled consistently so that responders are properly protected during incident management operations. The activation of the Worker Safety and Health Annex gives the Occupational Safety and Health Administration (OSHA) the responsibility to coordinate a comprehensive response involving federal, state, and local agencies and private-sector organizations to ensure the safety and health needs of responders are met. There is confusion, however, as to whether OSHA is acting as an advisory “coordinator” or as an enforcement agency. OSHA personnel at the WTC and the Gulf region reported they were not clear what role they must perform (and the language in the National Response Plan is not explicit). Thus, the need for a clear and comprehensive mandatory program.
Asbestos Disease in Australia: Looking Forward and Looking Back
Authors: Lamontagne A. D. , Hunter C. E. , Vallance D. , Holloway A. J.
Published: October 2008

This article provides an overview and analysis of recent developments in policy and practice in relation to asbestos disease in Australia. It complements three other concurrent publications in this issue representing important contributions of people and organizations toward addressing the health and social impacts of Australia's asbestos disease epidemic. The campaign to “Make James Hardie Pay” as well as the efforts of workers and advocates are profiled in this article as well as in this issue's Documents and Voices sections. Discussion of recent developments in asbestos-related disease research and mesothelioma surveillance is followed by articulation of the comprehensive public and social health response that is needed to fully engage and address the asbestos disease legacy and to apply lessons learned to help revive the currently waning societal commitment to occupational health and safety in Australia and elsewhere.
The Latrobe Valley: Perspectives on Asbestos Issues
Authors: Hamilton Vicki
Published: October 2008

The texts of two public addresses by a community advocate, Vicki Hamilton, and former asbestos worker, Geoff Swayn, are profiled in this issue's Voices section. Each articulates, in their own words, the need for continuing efforts to address the health and social impacts of Australia's ongoing asbestos disease epidemic, including the need for healing at the community and societal levels that parallel the needs of affected individuals and families. Their messages are relevant to similarly affected communities and societies internationally, particularly in relation to the need to reinvigorate societal commitment to occupational health and safety in Australia and elsewhere.
Letter: How to Drink the Sub-Prime Kool-Aid
Authors: Varian Hal R
Published: October 2008

Hal Varian, of UC Berkeley, points out that randomization could help avoid the adverse selection in the Treasury's proposed auctions of mortgage backed securities.
Governing Knowledge: Research Steering and Research Quality
Authors: Ozga Jenny
Published: October 2008

This article argues that the ‘quality’ debate in education research is not so much about quality as about creating the conditions in which research and knowledge production in the field of education can be managed and steered. The criticisms of research in education have destabilised the field and promoted its closer dependence on and alignment with policy. The paper connects changes in the nature of knowledge to developments in the governance of education, suggesting that experts and techno-scientific research are increasingly necessary not only as sources of information but as ways of ‘doing’ governing, especially through quantification and comparison.
The Mobility of University Students in Europe and Spain
Authors: Pineda Pilar , Moreno Victoria , Belvis Esther
Published: October 2008

The Bologna Process has taken an undeniable role in the development of the European Higher Education Space to create a shared framework at the higher education level. In this new framework, teachers' and students' mobility is the key element. This is one of the main aims that European Union education policies try to achieve. This study is about the mobility of Erasmus and Sicue students in the European Union and the Spanish university context. It tries to explain mobility through three basic lines of research: documentary analysis, the application of eligibility index and work field. The methodology used gathers qualitative and quantitative data from a sample of Erasmus and Sicue students. The results show that the participation in a mobility programme is not only connected with a personal profile but also with other factors that can promote or inhibit this decision. The most important factors are related to the family and relationship context, the features of programmes and the promotion that takes place in the universities.
Key Competencies for Education in a European Context: Narratives of Accountability or Care
Authors: Crick Ruth Deakin
Published: October 2008

This article addresses the ideological challenges and opportunities presented by the European Commission's commitment to the identification of key competencies for education and training, and the development of indicators which can be used to monitor and evaluate progress towards these competences across the European Union. It explores the backdrop of global changes which bring the notion of competences to the fore, worldwide, and then reports on the European Union's framework for competences. The construction of ‘competence’ is an ideological and political act, since it is an indication of a particular understanding of the ‘good life’, which may be different when viewed from within a social justice narrative or a neo-liberal narrative. The notion of ‘meta-competence’ is explored as a means of transcending the binary tension between an economic and a social narrative. European texts are best viewed as complex and multifaceted ‘collages' which are dynamic, rather than static, and the term ‘competence’ in the texts is a good example of this.
The Boundaries of Competency within Lisbon and Bologna: The Short-Cycle/foundation Learner
Authors: Brine Jacqueline
Published: October 2008

The concept of competency is considered both in relation to the educational competency of the short-cycle student described in the ‘Dublin Descriptors' of the Bologna Process and in the European Commission's European Qualifications Framework, and in relation to the legal competency that the European Commission has within the field of education and training. This article focuses specifically on the short-cycle/foundation degree introduced in 2003 into the pan-European Bologna Process, and considers its relevance to the European Union's Lisbon Strategy. It argues that the ‘short-cycle/foundation’ student represents the mid knowledge-skilled learner that is frequently missing from policies and analyses of the knowledge economy that concentrate on either ‘basic skills' learners or graduates/postgraduates and that this particular learner, clearly linked to employment, is located at the intersection of vocational and academic learning. The article also considers the role of the European Commission in both the Lisbon and Bologna Processes. Based on an analysis of policy texts the article suggests that the two definitions of competency, whilst quite distinct, are, at the level of policy, very closely connected and serve to increase the Commission's activities within areas of education that are beyond their legal competence.