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Test Sites (test + site)
Selected AbstractsIntegration of genotoxicity and population genetic analyses in kangaroo rats (Dipodomys merriami) exposed to radionuclide contamination at the Nevada Test Site, USAENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 2 2001Christopher W. Theodorakis Abstract We examined effects of radionuclide exposure at two atomic blast sites on kangaroo rats (Dipodomys merriami) at the Nevada Test Site, Nevada, USA, using genotoxicity and population genetic analyses. We assessed chromosome damage by micronucleus and flow cytometric assays and genetic variation by randomly amplified polymorphic DNA (RAPD) and mitochondrial DNA (mtDNA) analyses. The RAPD analysis showed no population structure, but mtDNA exhibited differentiation among and within populations. Genotoxicity effects were not observed when all individuals were analyzed. However, individuals with mtDNA haplotypes unique to the contaminated sites had greater chromosomal damage than contaminated-site individuals with haplotypes shared with reference sites. When interpopulation comparisons used individuals with unique haplotypes, one contaminated site had greater levels of chromosome damage than one or both of the reference sites. We hypothesize that shared-haplotype individuals are potential migrants and that unique-haplotype individuals are potential long-term residents. A parsimony approach was used to estimate the minimum number of migration events necessary to explain the haplotype distributions on a phylogenetic tree. The observed predominance of migration events into the contaminated sites supported our migration hypothesis. We conclude the atomic blast sites are ecological sinks and that immigration masks the genotoxic effects of radiation on the resident populations. [source] An analysis of P times reported in the Reviewed Event Bulletin for Chinese underground explosionsGEOPHYSICAL JOURNAL INTERNATIONAL, Issue 2 2005A. Douglas SUMMARY Analysis of variance is used to estimate the measurement error and path effects in the P times reported in the Reviewed Event Bulletins (REBs, produced by the provisional International Data Center, Arlington, USA) and in times we have read, for explosions at the Chinese Test Site. Path effects are those differences between traveltimes calculated from tables and the true times that result in epicentre error. The main conclusions of the study are: (1) the estimated variance of the measurement error for P times reported in the REB at large signal-to-noise ratio (SNR) is 0.04 s2, the bulk of the readings being analyst-adjusted automatic-detections, whereas for our times the variance is 0.01 s2 and (2) the standard deviation of the path effects for both sets of observations is about 0.6 s. The study shows that measurement error is about twice (,0.2 s rather than ,0.1 s) and path effects about half the values assumed for the REB times. However, uncertainties in the estimated epicentres are poorly described by treating path effects as a random variable with a normal distribution. Only by estimating path effects and using these to correct onset times can reliable estimates of epicentre uncertainty be obtained. There is currently an international programme to do just this. The results imply that with P times from explosions at three or four stations with good SNR (so that the measurement error is around 0.1 s) and well distributed in azimuth, then with correction for path effects the area of the 90 per cent coverage ellipse should be much less than 1000 km2,the area allowed for an on-site inspection under the Comprehensive Test Ban Treaty,and should cover the true epicentre with the given probability. [source] Process Considerations for Trolling Borehole Flow LogsGROUND WATER MONITORING & REMEDIATION, Issue 3 2006Phil L. Oberlander Horizontal hydraulic conductivity with depth is often understood only as a depth-integrated property based on pumping tests or estimated from geophysical logs and the lithology. A more explicit method exists for determining hydraulic conductivity over small vertical intervals by collecting borehole flow measurements while the well is being pumped. Borehole flow rates were collected from 15 deep monitoring wells on the Nevada Test Site and the Nevada Test and Training Range while continuously raising and lowering a high-precision impeller borehole flowmeter. Repeated logging passes at different logging speeds and pumping rates typically provided nine unique flow logs for each well. Over 60 km of borehole flow logs were collected at a 6.1-cm vertical resolution. Processing these data necessitated developing a methodology to delete anomalous values, smooth small-scale flow variations, combine multiple borehole flow logs, characterize measurement uncertainty, and determine the interval-specific lower limit to flow rate quantification. There are decision points in the data processing where judgment and ancillary analyses are needed to extract subtle hydrogeologic information. The analysis methodology indicates that processed measurements from a high-precision trolling impeller flowmeter in a screened well can confidently detect changes in borehole flow rate of ,0.7% of the combined trolling and borehole flow rate. An advantage of trolling the flowmeter is that the impeller is nearly always spinning as it is raised and lowered in the well and borehole flow rates can be measured at lower values than if measurements were taken while the flowmeter was held at a fixed depth. [source] Tahiti Intertwined: Ancestral Land, Tourist Postcard, and Nuclear Test SiteAMERICAN ANTHROPOLOGIST, Issue 1 2000Miriam Kahn In this article, I apply ideas from Foucault, Lefebvre, and Soja about thirdspace, or space beyond dualisms, to an understanding of'Tahiti" as a complex, intertwined place. For most Tahitians, a sense of place is rooted in land, which individuals describe as a nurturing mother. Genealogical ties to land define personal identities and social relationships. For the world at large, however, the perception of Tahiti is based on seductive, mass-mediated, touristic images. The perpeiuation of these images, whose origins go back two-hundred years, has become increasingly enmeshed in the economic and political agendas of the French colonial government. The resumption of nuclear testing in French Polynesia in 1995-96 and the subsequent rioting by Tahitians, which disseminated negative images throughout the world, provide a setting for an analysis of Tahiti that moves beyond dualisms. Tahiti is understood instead as an intertwined thirdspace, equally real and imagined, immediate and mediated, [place, colonialism, imagery, tourism, nuclear testing] [source] Multimethodological approach to investigate chamber tombs in the Sabine Necropolis at Colle del Forno (CNR, Rome, Italy)ARCHAEOLOGICAL PROSPECTION, Issue 2 2009Salvatore Piro Abstract Non-destructive geophysical prospecting methods are increasingly used for the investigation of archaeological sites, especially where a detailed physical and geometrical reconstruction of structures is required prior to any excavation work. Often, due to the limited size and depth of an archaeological structure, it may be rather difficult to single out its position and extent because of the generally low signal-to noise (S/N) ratio. This can be overcome by improving data acquisition and processing techniques and integrating different geophysical methods. In this work the results of a multimethodological surveys, used with the aim of detecting sharp discontinuities (boundary of cavities and fractures in the host medium) at the Archaeological Test Site of Sabine Necropolis at Research Area of National Research Council of Rome (Montelibretti, Italy) are shown. For the survey a combination of passive and active methods (magnetic, ground-penetrating radar (GPR), and dipole,dipole geoelectric (DDG)), topographical and three-dimensional laser scanner surveys and archaeological excavations were used to study the state of conservation of underground tombs. With all geophysical methods a high-resolution data acquisition was adopted with the aim of reconstructing a global vision of the study area. Signal processing and amplitude time-slice representation techniques were used for the analysis of GPR data. The bi-dimensional cross-correlation technique was applied to enhance the S/N ratio of the magnetic data. An example of the integration (both qualitative and quantitative) of these results is presented for a portion of the investigated area in the Sabine Necropolis at Colle del Forno (Rome, Italy). Archaeological excavations were then conducted systematically after completing the geophysical surveys and interpretations (from 2000 to 2006), which confirmed the location and shape of the individual chamber tombs with associated corridors. Copyright © 2009 John Wiley & Sons, Ltd. [source] Semiparametric Regression Modeling with Mixtures of Berkson and Classical Error, with Application to Fallout from the Nevada Test SiteBIOMETRICS, Issue 1 2002Bani Mallick Summary. We construct Bayesian methods for semiparametric modeling of a monotonic regression function when the predictors are measured with classical error, Berkson error, or a mixture of the two. Such methods require a distribution for the unobserved (latent) predictor, a distribution we also model semi-parametrically. Such combinations of semiparametric methods for the dose-response as well as the latent variable distribution have not been considered in the measurement error literature for any form of measurement error. In addition, our methods represent a new approach to those problems where the measurement error combines Berkson and classical components. While the methods are general, we develop them around a specific application, namely, the study of thyroid disease in relation to radiation fallout from the Nevada test site. We use this data to illustrate our methods, which suggest a point estimate (posterior mean) of relative risk at high doses nearly double that of previous analyses but that also suggest much greater uncertainty in the relative risk. [source] Variable-Pulse Nd:YAG Laser in the Treatment of Facial TelangiectasiasDERMATOLOGIC SURGERY, Issue 1 2006AVERY A. BEVIN MD BACKGROUND Variable-pulse 1,064 nm wavelength lasers have been used with good effectiveness on leg telangiectasias and reticular veins and have shown promising results on facial telangiectasias as well. OBJECTIVE To investigate the effectiveness of a variable-pulse neodymium:yttrium-aluminum-garnet (Nd:YAG) laser using a small spot size in the treatment of facial telangi-ectasias. METHODS Eight male patients (mean age 75 years) underwent a single treatment session using a variable-pulse 1.5 mm spot size Nd:YAG laser with epidermal cooling. Telangiectasia diameters were 0.3 to 2.0 mm. Test sites were performed using three pulse widths (3, 20, and 60 ms), with fluences varying depending on vessel size and response. Full treatments were per-formed using test parameters giving the best response. Thirteen weeks later, the patients returned for final evaluation and satisfaction rating. RESULTS Fluences ranged from 226 to 425 J/cm2, with smaller vessels requiring larger energies. Pulse duration was equally divided between the 20 and 60 ms settings. The shortest pulse width (3 ms) was inferior in all patients. Longer pulse durations achieved superior vessel elimination with minimal immediate purpura and no postinammatory hyperpigmentation. The average mean vessel clearance was 26 to 50% in half of the patients and 51 to 75% in the other half as evaluated by three unbiased dermatologists with extensive laser experience. CONCLUSION A small,spot size Nd:YAG laser using a pulse width of 20 ms or higher appears to be effective in clearing a significant percentage of facial telangectasias with a single pass. The side effects were minimal. [source] Initial pattern of angiogenesis and bone formation following lateral ridge augmentation using rhPDGF and guided bone regeneration: an immunohistochemical study in dogsCLINICAL ORAL IMPLANTS RESEARCH, Issue 1 2010Frank Schwarz Abstract Objectives: To evaluate (i) the effects of rhPDGF-BB on localized ridge augmentation using a natural bone mineral (NBM), and (ii) the influence of a collagen membrane (CM) on factor activity. Materials and methods: Chronic-type alveolar ridge defects (n=4 dogs) were randomly allocated in a split-mouth design as follows: upper jaw: NBM+rhPDGF-BB+CM (test) vs. NBM+rhPDGF-BB (control), and lower jaw: NBM+rhPDGF-BB+CM (test) vs. NBM+CM (control). After 3 weeks, dissected blocks were prepared for immunohistochemical (angiogenesis , TG) and histomorphometrical analysis [e.g. augmented area (AA), mineralized , (MT), non-mineralized tissue (NMT) (mm2)]. Results: Lower jaw: TG and mineralization of AA mainly originated from the defect borders. Test sites revealed a pronounced TG antigen reactivity and higher AA and MT values (mean and median). Upper jaw: control sites revealed a dislocation of AA in caudal direction, but also an improved vascularization in the peripheral wound area. While MT values (median) appeared to be comparable in both groups, AA, NMT, and NBM values (mean and median) tended to be higher at test sites. Conclusions: It was concluded that (i) rhPDGF-BB soak-loaded on NBM might have the potential to support bone formation at chronic-type lateral ridge defects, and (ii) the application of CM did not seem to interfere with the factor activity, but ensured a stabilization of the graft particles. To cited this article: Schwarz F, Ferrari D, Podolsky L, Mihatovic I, Becker J. Initial pattern of angiogenesis and bone formation following lateral ridge augmentation using rhPDGF and guided bone regeneration: an immunohistochemical study in dogs. Clin. Oral Impl. Res. 21, 2010; 90,99. [source] Areolar Cosmetic Tattoo Ink Darkening: A Complication of Q-Switched Alexandrite Laser TreatmentDERMATOLOGIC SURGERY, Issue 1 2002Sung-Eun Chang MD background and objective. Medical tattooing of the areola is widely performed in Korea. However, cosmetic tattoos containing flesh-tone, purple-red, and yellow dyes are sometimes resistant to Q-switched laser and may even become darker. method. Two Korean women in their 30s who had a mastectomy got light brown to red areolar medical tattoos but they were not satisfied with the shape and size of the tattoos. They underwent Q-switched alexandrite laser treatment with a 3 mm collimated beam at fluences of 7.5,8 J/cm2 in order to trim the irregular contour and reduce the diameter of the tattoos. results. Within 5 minutes a dark gray to black discoloration of the treated area was evident and remained dark for 6 weeks. Improvement was not noted after two further Q-switched Nd:YAG laser treatments. conclusion. Medical areolar tattoos should be approached with extra caution when attempting their removal with high-energy pulsed lasers such as Q-switched alexandrite laser and a small test site should be performed prior to treatment. [source] Self-Limited Adverse Reaction to Human-Derived Collagen Injectable ProductDERMATOLOGIC SURGERY, Issue 10 2000Brent R. Moody MD Background. Soft tissue augmentation is a common and safe cosmetic and reconstructive procedure. Objective. We describe a temporary and self-limited adverse reaction to Dermalogen. Methods. Clinical and histologic evaluation following an adverse reaction noted at a Dermalogen skin test site. Results. Our patient was found to have a foreign body reaction to Dermalogen. Conclusion. Dermalogen, a form of acellular human collagen, may induce a foreign body reaction. [source] On-line dynamic security assessment to mitigate the risk of blackout in the Italian power systemEUROPEAN TRANSACTIONS ON ELECTRICAL POWER, Issue 8 2008Diego Cirio Abstract This paper provides a comprehensive survey of the major initiatives and research projects recently carried out by the Italian system operator, Cesi Ricerca, and Universities on power system monitoring, defense, and security assessment. The technological and methodological features of an advanced wide area measurement system (WAMS) are described and the main aspects of an adaptive system for event-based automatic load shedding are presented. Then preventive and corrective security assessment, with particular emphasis to dynamic security assessment,DSA, is introduced. Results from an EU project, where the Italian power system served as a test site for on-line experimentation, are reported. Considering the need for very fast assessment by stability indices, a complementary approach to the above "conventional" DSA, currently under way, is described in further detail. The methodology relies on a correlation model relating significant power system measurements with local loadability margins. Results of some tests on the Italian power system are presented and discussed. Copyright © 2008 John Wiley & Sons, Ltd. [source] ANNA: A new prediction method for bioassessment programsFRESHWATER BIOLOGY, Issue 1 2005Simon Linke Summary 1. Cluster analysis of reference sites with similar biota is the initial step in creating River Invertebrate Prediction and Classification System (RIVPACS) and similar river bioassessment models such as Australian River Assessment System (AUSRIVAS). This paper describes and tests an alternative prediction method, Assessment by Nearest Neighbour Analysis (ANNA), based on the same philosophy as RIVPACS and AUSRIVAS but without the grouping step that some people view as artificial. 2. The steps in creating ANNA models are: (i) weighting the predictor variables using a multivariate approach analogous to principal axis correlations, (ii) calculating the weighted Euclidian distance from a test site to the reference sites based on the environmental predictors, (iii) predicting the faunal composition based on the nearest reference sites and (iv) calculating an observed/expected (O/E) analogous to RIVPACS/AUSRIVAS. 3. The paper compares AUSRIVAS and ANNA models on 17 datasets representing a variety of habitats and seasons. First, it examines each model's regressions for Observed versus Expected number of taxa, including the r2, intercept and slope. Second, the two models' assessments of 79 test sites in New Zealand are compared. Third, the models are compared on test and presumed reference sites along a known trace metal gradient. Fourth, ANNA models are evaluated for western Australia, a geographically distinct region of Australia. The comparisons demonstrate that ANNA and AUSRIVAS are generally equivalent in performance, although ANNA turns out to be potentially more robust for the O versus E regressions and is potentially more accurate on the trace metal gradient sites. 4. The ANNA method is recommended for use in bioassessment of rivers, at least for corroborating the results of the well established AUSRIVAS- and RIVPACS-type models, if not to replace them. [source] Natural-gradient tracer experiments in epikarst: a test study in the Acqua dei Faggi experimental site, southern ItalyGEOFLUIDS (ELECTRONIC), Issue 3 2008E. PETRELLA Abstract Two natural-gradient tracer experiments were carried out using borehole fluorometers in order to characterize the internal structure of epikarstic horizons and analyze subsurface flow within these high-conductivity layers. The experiments were carried out in a test site in southern Italy where the epikarst is made up of an upper part with pervasive karstification and a lower part without pervasive karstification. Injection and observation boreholes were 6.9 m apart. An initial experiment demonstrated that wider (conduits) and narrower (fractures and bedding planes) openings coexist in a well-connected network within the lower epikarst. The adjusted aperture of the opening network (105 ,m) suggests that conduits are subordinately developed. The lower epikarstic horizon is hydraulically similar to granular porous media and Darcy's law can be applied to describe groundwater flow. A small value of longitudinal dispersivity (0.13 m) shows that variations in the velocity field in the direction of flow are less significant than those typical of carbonate systems at the same experiment scale. A second experiment demonstrated that longitudinal dispersivity (2.42 m) in the upper epikarst is in agreement with findings in other carbonates at the same experiment scale. However, despite the higher dispersivity and more pervasive karstification, the mean tracer velocity (3.7 m day,1) in the upper epikarst is slightly lower than the velocity in the lower epikarst (13.6 m day,1). [source] The upper continental crust, an aquifer and its fluid: hydaulic and chemical data from 4 km depth in fractured crystalline basement rocks at the KTB test siteGEOFLUIDS (ELECTRONIC), Issue 1 2005I. STOBER Abstract Detailed information on the hydrogeologic and hydraulic properties of the deeper parts of the upper continental crust is scarce. The pilot hole of the deep research drillhole (KTB) in crystalline basement of central Germany provided access to the crust for an exceptional pumping experiment of 1-year duration. The hydraulic properties of fractured crystalline rocks at 4 km depth were derived from the well test and a total of 23100 m3 of saline fluid was pumped from the crustal reservoir. The experiment shows that the water-saturated fracture pore space of the brittle upper crust is highly connected, hence, the continental upper crust is an aquifer. The pressure,time data from the well tests showed three distinct flow periods: the first period relates to wellbore storage and skin effects, the second flow period shows the typical characteristics of the homogeneous isotropic basement rock aquifer and the third flow period relates to the influence of a distant hydraulic border, probably an effect of the Franconian lineament, a steep dipping major thrust fault known from surface geology. The data analysis provided a transmissivity of the pumped aquifer T = 6.1 × 10,6 m2 sec,1, the corresponding hydraulic conductivity (permeability) is K = 4.07 × 10,8 m sec,1 and the computed storage coefficient (storativity) of the aquifer of about S = 5 × 10,6. This unexpected high permeability of the continental upper crust is well within the conditions of possible advective flow. The average flow porosity of the fractured basement aquifer is 0.6,0.7% and this range can be taken as a representative and characteristic values for the continental upper crust in general. The chemical composition of the pumped fluid was nearly constant during the 1-year test. The total of dissolved solids amounts to 62 g l,1 and comprise mainly a mixture of CaCl2 and NaCl; all other dissolved components amount to about 2 g l,1. The cation proportions of the fluid (XCa approximately 0.6) reflects the mineralogical composition of the reservoir rock and the high salinity results from desiccation (H2O-loss) due to the formation of abundant hydrate minerals during water,rock interaction. The constant fluid composition suggests that the fluid has been pumped from a rather homogeneous reservoir lithology dominated by metagabbros and amphibolites containing abundant Ca-rich plagioclase. [source] Detection of preferential infiltration pathways in sinkholes using joint inversion of self-potential and EM-34 conductivity dataGEOPHYSICAL PROSPECTING, Issue 5 2007A. Jardani ABSTRACT The percolation of water in the ground is responsible for measurable electric potentials called self-potentials. These potentials are influenced by the distribution of the electrical conductivity of the ground. Because sinkholes are associated both with self-potential and electrical conductivity anomalies, a joint inversion of EM-34 conductivity and self-potential data is proposed as a way of delineating the location of these features. Self-potential and EM conductivity data were obtained at a test site in Normandy (France) where sinkholes and crypto-sinkholes are present over a karstic area in a chalk substratum overlain by clay-with-flint and loess covers. The presence of sinkholes and crypto-sinkholes is associated with negative self-potential anomalies with respect to a reference electrode located outside the area where the sinkholes are clustered. The sinkholes also have a conductivity signature identified by the EM-34 conductivity data. We used the simulated-annealing method, which is a global optimization technique, to invert jointly EM-34 conductivity and self-potential data. Self-potential and electrical conductivity provide clear complementary information to determine the interface between the loess and clay-with-flint formations. The sinkholes and crypto-sinkholes are marked by depressions in this interface, focusing the groundwater flow towards the aquifer contained in the chalk substratum. [source] A comparison of cross-hole electrical and seismic data in fractured rockGEOPHYSICAL PROSPECTING, Issue 2 2004J.V. Herwanger ABSTRACT Cross-hole anisotropic electrical and seismic tomograms of fractured metamorphic rock have been obtained at a test site where extensive hydrological data were available. A strong correlation between electrical resistivity anisotropy and seismic compressional-wave velocity anisotropy has been observed. Analysis of core samples from the site reveal that the shale-rich rocks have fabric-related average velocity anisotropy of between 10% and 30%. The cross-hole seismic data are consistent with these values, indicating that observed anisotropy might be principally due to the inherent rock fabric rather than to the aligned sets of open fractures. One region with velocity anisotropy greater than 30% has been modelled as aligned open fractures within an anisotropic rock matrix and this model is consistent with available fracture density and hydraulic transmissivity data from the boreholes and the cross-hole resistivity tomography data. However, in general the study highlights the uncertainties that can arise, due to the relative influence of rock fabric and fluid-filled fractures, when using geophysical techniques for hydrological investigations. [source] Evaluation of the MODFLOW-2005 Conduit Flow ProcessGROUND WATER, Issue 4 2010Melissa E. Hill The recent development of the Conduit Flow Process (CFP) by the U.S. Geological Survey (USGS) provides hydrogeologic modelers with a new tool that incorporates the non-Darcian, multiporosity components of flow characteristic of karst aquifers. CFP introduces new parameters extending beyond those of traditional Darcian groundwater flow codes. We characterize a karst aquifer to collect data useful for evaluating this new tool at a test site in west-central Florida, where the spatial distribution and cross-sectional area of the conduit network are available. Specifically, we characterize: (1) the potential for Darcian/non-Darcian flow using estimates of specific discharge vs. observed hydraulic gradients, and (2) the temporal variation for the direction and magnitude of fluid exchange between the matrix and conduit network during extreme hydrologic events. We evaluate the performance of CFP Mode 1 using a site-scale dual-porosity model and compare its performance with a comparable laminar equivalent continuum model (ECM) using MODFLOW-2005. Based on our preliminary analyses, hydraulic conductivity coupled with conduit wall conductance improved the match between observed and simulated discharges by 12% to 40% over turbulent flow alone (less than 1%). [source] Influence of Small-Scale Heterogeneities on Contaminant Transport in Fractured Crystalline RockGROUND WATER, Issue 5 2006Ralph Mettier We present a sequence of purely advective transport models that demonstrate the influence of small-scale geometric inhomogeneities on contaminant transport in fractured crystalline rock. Special weight is placed on the role of statistically generated variable fracture apertures. The fracture network geometry and the aperture distribution are based on information from an in situ radionuclide retardation experiment performed at Grimsel test site (Swiss Alps). The obtained breakthrough curves are fitted with the advection dispersion equation and continuous-time random walks (CTRW). CTRW is found to provide superior fits to the late-arrival tailing and is also found to show a good correlation with the velocity distributions obtained from the hydraulic models. The impact of small-scale heterogeneities, both in fracture geometry and aperture, on transport is shown to be considerable. [source] Ground Water Transfer Initiates Complete Reductive Dechlorination in a PCE-Contaminated AquiferGROUND WATER MONITORING & REMEDIATION, Issue 3 2007R. Lookman We conducted a field test to investigate whether ground water transfer from one site (showing complete natural reductive dechlorination of chlorinated ethenes to ethene) could induce full reductive dechlorination at another site polluted with tetrachloroethene and its partial dechlorination products trichloroethene and cis -dichloroethene (cDCE). Addition of electron donor (lactate) at the test site established low redox conditions but did not stimulate further dechlorination past cDCE. After transferring 2 m3 of ground water from the first site to the test site, full dechlorination commenced and high levels of ethene were measured to distances up to 6 m downstream of the injection location within 7 months. Ground water samples from monitoring wells were analyzed before and after inoculation of the test site for the presence of Dehalococcoides species (16S ribosomal RNA) and vinyl chloride reductase (vCRA) genes using the polymerase chain reaction. These tests showed that Dehalococcoides species were present both before and after ground water transfer, while vCRA genes were detected at the test site only after ground water transfer. The vCRA genes were detected in ground water samples collected 6 m downstream of the injection locations 7 months after ground water transfer, suggesting that the microorganisms carrying the dehalogenase genes were effectively transported in the aquifer. [source] The chick chorioallantoic membrane as a novel in vivo model for the testing of biomaterialsJOURNAL OF BIOMEDICAL MATERIALS RESEARCH, Issue 2 2002T.I. Valdes Abstract Current in vivo models for testing biomaterials are time and labor intensive as well as expensive. This article describes a new approach for testing biomaterials in vivo using the chorioallantoic membrane (CAM) of the developing chicken embryo, as an alternative to the traditional mammalian models. Fertilized chicken eggs were incubated for 4 days, at which time a small window was cut in the shell of the egg. After 1 week of incubation, the CAM received several test materials, including the endotoxin LPS, a cotton thread and a Silastic tubing. One day and 1 week later, the tissue response to the test materials was assessed using gross, histological, and scanning electron microscope evaluations. The inflammatory response of the chorioallantoic membrane to biomaterials was fully characterized and found to be similar to that of the mammalian response and was also seen to vary according to test materials. We also found that the structure and geometry of the test materials greatly influenced the incorporation of the samples in the CAM. The similarity of the tissue response of the CAM with the mammalian models, plus the low cost, simplicity, and possibility to continuously visualize the test site through the shell window make this animal model particularly attractive for the rapid in vivo screening of biomaterials. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res 62: 273,282, 2002 [source] Mesenchymal stem cells and platelet-rich plasma enhance bone formation in sinus grafting: a histomorphometric study in minipigsJOURNAL OF CLINICAL PERIODONTOLOGY, Issue 6 2008Francesco Pieri Abstract Objectives: Autologous, allogenic, and alloplastic materials for sinus augmentation have specific drawbacks, which has stimulated an ongoing search for new materials and tissue-engineering constructs. We investigated whether mesenchymal stem cells (MSCs) and platelet-rich plasma (PRP) seeded on a fluorohydroxyapatite (FH) scaffold can improve bone formation and bone-to-implant contact (BIC) in maxillary sinus grafting. Material and Methods: Bilateral sinus augmentation procedures were performed in eight minipigs. MSCs, PRP, and FH scaffold (test site) or FH alone (control site) were grafted in each maxillary sinus. Distal to the osteotomy, one dental implant per sinus was placed in the grafting material through the facial sinus wall. The animals were killed 3 months after grafting, and block sections of the implant sites were harvested and prepared for histomorphometric analysis. Results: After 12 weeks, a significant increase in bone formation occurred in the test sites compared with the control sites (42.51%versus 18.98%; p=0.001). In addition, BIC was significantly greater in the test sites compared with the control sites in the regenerated area (23.71%versus 6.63%; p=0.028). Conclusions: These findings show that sinus augmentation with MSCs,PRP, combined with FH may enhance bone formation and osseointegration of dental implants compared with FH alone in minipigs. [source] Changes in vasoactive intestinal peptide in gingival crevicular fluid in response to periodontal treatmentJOURNAL OF CLINICAL PERIODONTOLOGY, Issue 6 2002Gerard J. Linden Abstract Aims: To evaluate the role of the anti-inflammatory neuropeptide vasoactive intestinal peptide (VIP) in periodontal health and disease and to determine the effects of periodontal treatment, resulting in a return to periodontal health, on the levels of VIP in gingival crevicular fluid (GCF). Methods: At baseline, 10 subjects with periodontitis (nine females, one male, mean age 43.0, SD 7.3) started a course of non-surgical periodontal treatment. Clinical indices were measured at one periodontitis and one clinically healthy site at an initial visit and at 8 weeks after the completion of treatment in each subject. A 30-s sample of GCF was collected from each test site using perio paper strips. The volume of GCF was measured and each sample subsequently analysed for VIP by radioimmunoassay. One healthy site was sampled from each member of a control group (10 females, mean age 29.9, SD 8.2 years) with clinically healthy gingiva and no periodontitis. Results: The clinical condition of all periodontitis sites improved as a result of periodontal treatment. The levels of VIP (pg/30 s sample) in periodontitis-affected sites fell significantly from 302.0 (SD 181.2) at the initial visit to 78.0 (54.4) after treatment, p = 0.007. The reduction in the concentration of VIP (pg/µL) in GCF from 524.3 (322.3) to 280.8 (280.2) was not statistically significant. The levels of VIP in clinically healthy sites fell from 115.5.5 (74.3) to 77.8 (32.3), n.s. and the concentration changed little from 883.8 (652.1) to 628.7 (323.3), n.s. There were substantially smaller amounts of VIP (25.8, SD 12.8) pg in healthy sites sampled from control subjects. Conclusions: VIP is present in GCF in greater quantities in periodontitis-affected than clinically healthy sites. In addition, the reduction in inflammation resulting from effective periodontal treatment is associated with a reduction in the levels of VIP in gingival crevicular fluid. [source] An aging Interventions Testing Program: study design and interim reportAGING CELL, Issue 4 2007Richard A. Miller Summary The National Institute on Aging's Interventions Testing Program (ITP) has developed a plan to evaluate agents that are considered plausible candidates for delaying rates of aging. Key features include: (i) use of genetically heterogeneous mice (a standardized four-way cross), (ii) replication at three test sites (the Jackson Laboratory, TJL; University of Michigan, UM; and University of Texas, UT), (iii) sufficient statistical power to detect 10% changes in lifespan, (iv) tests for age-dependent changes in T cell subsets and physical activity, and (v) an annual solicitation for collaborators who wish to suggest new interventions for evaluation. Mice in the first cohort were exposed to one of four agents: aspirin, nitroflurbiprofen (NFP), 4-OH-,-phenyl-N-tert-butyl nitrone (4-OH-PBN), or nordihydroguiaretic acid (NDGA). An interim analysis was conducted using survival data available on the date at which at least 50% of the male control mice had died at each test site. Survival of control males was significantly higher, at the interim time-point, at UM than at UT or TJL; all three sites had similar survival of control females. Males in the NDGA group had significantly improved survival (P = 0.0004), with significant effects noted at TJL (P < 0.01) and UT (P < 0.04). None of the other agents altered survival, although there was a suggestion (P = 0.07) of a beneficial effect of aspirin in males. More data will be needed to determine if any of these compounds can extend maximal lifespan, but the current data show that NDGA reduces early life mortality risks in genetically heterogeneous mice at multiple test sites. [source] Measurement of the setting expansion of phosphate-bonded investment materials: Part I , Development of the Casting-Ring TestJOURNAL OF ORAL REHABILITATION, Issue 7 2004C. H. Lloyd summary, The setting expansion is an important property for a phosphate-bonded investment material. This research was undertaken to investigate a test that might be suitable for its measurement when used in a Standard. In the ,Casting-Ring Test', the investment sample is contained in a steel ring and expands to displace a precisely positioned pin. Variables with the potential to alter routine reproduction of the value were investigated. The vacuum-mixer model is a production laboratory variable that must not be ignored and for this reason, experiments were repeated using a different vacuum-mixer located at a second test site. Restraint by the rigid ring material increased expansion, while force on the pin reduced it. Expansion was specific to the lining selected. Increased environmental temperature decreased the final value. Expansion was still taking place at a time at which its value might be measured. However, when these factors are set, the reproducibility of values for setting expansion was good at both test sites (coefficient of variation 14%, at most). The results revealed that with the control that is available reliable routine measurement is possible in a Standard test. The inter-laboratory variable, vacuum-mixer model, produced significant differences and it should be the subject of further investigation. [source] Cambium cell stimulation from surgical release of the periosteumJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 3 2003Timothy M. Simon An autograft of periosteal tissue containing cambium cells has potential to become chondrogenic or osteogenic depending on the regeneration repair strategies. The potential number of harvestable cambium cells diminishes with age. Other factors may be associated with a reduction in the number or variable yields of cambium cells including harvest technique, harvest site location, and the time interval from harvest to implantation. Attempts to increase the number of cambium cells have included improvements in harvesting and handling technique, and expansion of the cells in tissue culture. An ,in situ" stimulation and proliferation technique would offer the potential for increasing the number of cambium cells in a cost-effective manner for transplantation without the need for expansion in tissue culture. The hypothesis tested was that surgical release of the periosteum and its deep inner underlying cambium layer by sharply incising through the superficial periosteal fibrous layer down to and scoring the cortical bone surface would increase the number of cambium cells that could be harvested at a later time period. Two techniques for periosteal release were used to stimulate a proliferation of the underlying cambium layer and increase the cambium cells for harvest in skeletally mature goats: (1) sharply scoring all four-sides of the tissue test site perimeter, and (2) sharply scoring only two sides of the tissue test site. The two-sided and four-sided release scoring of the periosteum induced stimulatory responses in the number of cambium cells. In addition, a marked increase in mRNA expression for BMP-2 (p < 0.001) was observed within 24 h and remained elevated over baseline values for up to 96 h after this stimulation to the cambium layer. © 2002 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved. [source] BENTHIC MARINE ALGAL HERBARIUM OF LONG ISLAND SOUND DIGITAL COLLECTIONJOURNAL OF PHYCOLOGY, Issue 2001Article first published online: 24 SEP 200 Cudiner, S.2, Gillies, N.2 & Yarish, C.1 1Department of Ecology and Evolutionary Biology, University of Connecticut, Stamford, CT 06901-23151; 2Jeremy Richard Library, University of Connecticut, Stamford, CT 06901-2315 University of Connecticut presents the "Benthic Marine Algal Herbarium of Long Island Sound Digital Collection." When Phase One of this project is completed, this collection will include an online herbarium of all Long Island Sound macroalgae species. The database will be on the web and open to the public. The taxonomy and descriptive text are part of a collaboration between the University of Connecticut and NEAS. Database features include the ability to create searches and generate sets based on subjects, division, class, order, family, genus, habitat, species, keyword, location, etc. Each record will be cataloged according to Dublin Core cataloging guidelines. All species have a thumbnail image and a larger image for full viewing. TIFF files will be archived and available in the future (10mg images). Certain species will be marked as a teaching collection and made available upon request on a CDrom for teaching purposes. Future plans include expanding the database geographically in the Northeast. The database is located and maintained on a server at the Homer Babbidge Library on the UConn Storrs campus. The information is in Microsoft Access, and is made available for viewing and searching on the web through ColdFusion. This online collection is in the process of being created, a test site is now available at: http://norman.lib.uconn.edu:6550/algae/algaesearch.cfm (hit enter for all records or use search term: lamin) [source] Variations in the contents of heavy metals in arable soils of a major urban wetland inlet drainage system of Lake Victoria, UgandaLAKES & RESERVOIRS: RESEARCH AND MANAGEMENT, Issue 2 2010Jolocam Mbabazi Abstract Little is known about the effects of urbanization on the chemical quality of soils in suburban wetland inlet drainage systems to the Uganda side of Lake Victoria, on which food crops are extensively grown. It is feared that pollution in the soils might eventually enter food chains through such crops being consumed by urban populations unaware of their occurrence. Soil samples were collected from cultivated areas of a major wetland drainage system (Nakivubo Channel), at Kampala, Ubanda, near Lake Victoria and from a rural control wetland site (Senge). The soil from this site had similar properties as those from the urban test site (i.e., soil texture; porosity; humus content). Analysis of heavy metals with atomic absorption spectrophotometry (AAS) yielded the following soil concentration ranges: manganese (190,780), cadmium (<0.001,1.0), zinc (6.0,10.0) and lead (10,20 mg kg,1) dry weight for the control site, and 450,900, 1.0,2.0, 131,185, 40,60 mg kg,1 dry weight, respectively, for the urban wetland, indicative of relatively heavy metal pollution in the suburban drainage system. Heavy metal levels in cocoyam (Colocasia Esculenta) and sugarcane (Saccharum Officinarum) grown on both wetland soils also were evaluated via AAS with a modified wet-acid-digestion technique. The results highlighted high cadium and lead levels (P , 0.0003) in the crops from urban wetland cultivation. Cadmium and lead concentrations in cocoyam from urban wetland soils exceeded those from the control site by 0.17 and 3.54 mg kg,1, respectively. The corresponding results for sugarcane indicated a similar increase of 0.56 and 2.14 mg kg,1 of juice extract. Cadmium and lead levels in both urban wetland crops were higher than the maximum permissible limits of the Codex Alimentarius Commission, indicating that these concentrations pose potential health risks to urban consumers, and call for early counter-measures to combat urban pollution entering the lake. [source] Pilot study examining the combined use of pulsed dye laser and topical Imiquimod versus laser alone for treatment of port wine stain birthmarksLASERS IN SURGERY AND MEDICINE, Issue 9 2008Cheng-Jen Chang MD Abstract Background and Objective The objective of this study was to improve port wine stain (PWS) therapeutic outcome in response to laser therapy. Our specific aim was to determine whether the combined use of pulsed dye laser (PDL) therapy and topical Imiquimod versus PDL alone can improve PWS therapeutic outcome. Study Design/Materials and Methods This pilot study involved a retrospective review of 20 subjects, all Asian, with PWS. Subject ages ranged between 3 and 56 years. Upon enrollment, three test sites were prospectively identified on each subject for treatment assignments to the following regimens: (A) PDL+Imiquimod; (B) PDL alone; and (C) Imiquimod alone. PDL test sites received a single treatment with a 585 nm wavelength; 1.5 milliseconds pulse duration; spot size 7 mm using a light dosage of 10 J/cm2 with cryogen spray cooling. For the PDL+Imiquimod and Imiquimod alone test sites, subjects were instructed to apply Imiquimod topically to the sites once daily for 1 month after PDL exposure. Subjects were followed-up at 1, 3, 6, and 12 months after PDL exposure to evaluate each of the three test sites. The primary efficacy measurement was the quantitative assessment of blanching responses as measured by a DermoSpectrometer to calculate the hemoglobin-index of each site at 1, 3, 6, and 12 months after PDL exposure. Subjects were also closely monitored for any adverse effects. Results Based on paired sample test analysis, there were clinically, and statistically significant, differences in blanching responses over time favoring PWS receiving PDL+Imiquimod as compared to either PDL or Imiquimod alone (P<0.05). At 12 months, it should be noted that there was some evidence of redarkening of PWS test sites treated by PDL+Imiquimod and PDL alone, presumably due to revascularization of blood vessels. However, based on comparison of the hemoglobin-indices determined at 1 and 12 months after PDL exposure, there was less revascularization of PWS test sites treated with PDL+Imiquimod as compared to PDL alone (P<0.05). Transient hyperpigmentation was noted in 10% (n,=,2) and 40% (n,=,8) of subjects on the PDL+Imiquimod and PDL alone test sites, respectively. On all sites, hyperpigmentation resolved spontaneously without medical intervention within 6 months. Permanent hypopigmentation or scarring was not observed on any test site. Conclusion Based on the results of this pilot study, PDL+Imiquimod resulted in superior blanching responses over time as compared to PDL alone for treatment of test sites on PWS lesions. Although the PDL+Imiquimod approach is intriguing, clinical validation in large PWS patient samples is required. Lesers Surg. Med. 40:605,610, 2008. © 2008 Wiley-Liss, Inc. [source] High Frequency AC Power SystemNAVAL ENGINEERS JOURNAL, Issue 4 2008RAYMOND M. CALFO The Navy's Next Generation Integrated Power System (NGIPS) master plan calls for the evolution of the IPS system from its current medium voltage, 60 Hz state to a high-frequency, medium-voltage AC (HFAC) system in the next 10 years. Beyond that, and pending development of key protection components, a medium-voltage DC system will be considered for implementation. The master plan calls for power generation modules at three power levels across these systems: ,A low power level (2,5 MW) driven by a fuel-efficient diesel prime mover, ,A medium power level (10,15 MW) driven by a gas turbine, and ,A main propulsion power level (20,40 MW) driven by a gas turbine. EMD is currently developing a high-speed, high-frequency, liquid-cooled generator under contract with NAVSEA that will effectively demonstrate the mid-level generator for the HFAC system. It will be coupled directly to the output of a GE LM1600 Gas Turbine to provide a TG set with power density four times more favorable than conventional ATG sets. The generator development is proceeding favorably, with testing at the Navy's land-based test site (LBTS) expected to begin in July 2008. The technology embodied in the high-speed generator can be easily extrapolated to main turbine generator power levels. Given the availability of prime movers at appropriate speeds, the power generation modules for the HFAC system, at all three power levels, could be provided in a much shorter time frame than noted in the NGIPS master plan. This paper will explore the combinations of prime movers and advanced generators that would suit the three power generation modules of the HFAC system. A description of the prime mover and the generator used for each module will be provided to demonstrate the modest level of development needed. The performance parameters for each generation module will be provided, along with key characteristics and dimensions for the set. In the end, the paper will make the case that demonstration of a HFAC power generation system can be made in the short term, allowing the shipbuilding community to take advantage of the benefits of state-of-the-art power dense electrical generation. [source] Pilot Scale Demonstration of the Electrochemical Peroxidation Process at a Petroleum Spill SiteREMEDIATION, Issue 1 2000William P. Healy In a pilot test experiment involving approximately 200,000 gallons of groundwater, Electrochemical Peroxidation (ECP) was used to degrade aqueous phase volatile organic compounds (VOCs) including benzene, toluene, ethylbenzene, and xylene (BTEX) compounds and methyl tertbutyl ether (MTBE) from a petroleum spill. ECP involves a form of the Fenton's Reagent reaction, which uses electrochemically generated iron and dilute hydrogen peroxide (<30 mg/L) to break down organic molecules through oxidation to carbon dioxide and water. This article discusses a pilot scale demonstration of the ECP technology and its application to aqueous phase organic contaminants. The remedial approach used at the pilot test site involves three phases: (1) ex-situ chemical oxidation, (2) in-situ oxidation by reinjection of treated effluent near the plume origin, and (3) reestablishment of aerobic biodegradation as the residual hydrogen peroxide discharged to a series of upgradient wells degrades to oxygen. Analytical results of the pilot demonstration indicate that the ex-situ chemical oxidation reduced total BTEX concentrations in groundwater from over 1,000 ppb to undetectable concentrations (<1 ppb). © 2000 John Wiley & Sons, Inc. [source] | |||||||||||||||||||||||||||||||||||||