bluuebunny/crossref_metadata_2025 huggingface dataset:
Determination of porosity of platy materials using slit-shaped and bevelled pores
Authors: Delon J. F. , Lietard O. , Cases J. M. , Yvon J.
Published: November 2006

The pore-size distribution of kaolinite has been studied by nitrogen desorption isotherms. A new method is proposed which takes account of the fact that the intraparticle or ‘internal’ area is small in comparison with the total surface area. The crystals form dihedral angles with one another, and the irregularities of the crystal edges form a slit-shaped internal pore system. When the nitrogen pressure increases, the condensed volume in the pores grows by an amount greater than predicted by de Boer's law. This excess is shown to result from capillary condensation in bevelled pores and this accounts for the main part of the intercrystalline or ‘external’ porosity. A model of condensation in bevelled capillaries has been developed and its range of validity determined.
Dissolution of apatite in North Sea Jurassic sandstones: implications for the generation of secondary porosity
Authors: Morton A. C.
Published: November 2006

Heavy-mineral studies on Jurassic sandstones from the central and northern North Sea areas and from the Lossiemouth Borehole (onshore NE Scotland) show that the dissolution of apatite is a function of depositional environment rather than burial depth. In the shallow marine Upper Jurassic sands of the Claymore, Clyde and Tartan Fields, and in the deeper-water Magnus sands, apatite is ubiquitous, even where burial depths exceed 3800 m. Conversely, the fluvio-deltaic sands of the Beatrice, Heather, Ninian and Murchison Fields, and of the Lossiemouth Borehole, have suffered apatite dissolution, although burial depths range from very shallow (Lossiemouth Borehole) to about 3300 m. This clearly indicates that apatite dissolution has taken place through penetration of low-pH meteoric groundwaters at a very early stage in diagenesis, and that high-temperature fluids circulating in deep burial have had little or no effect. This is in accord with patterns of mineral dissolution observed in other sedimentary basins and in the North Sea Palaeocene. Although dissolution of heavy minerals is unlikely to generate significant secondary porosity, the process is nevertheless caused by the same pore-fluids that dissolve major framework constituents. Patterns of heavy-mineral dissolution therefore provide clues to the nature of these pore-fluids. Here, the relative stability of apatite is particularly significant. The order of stability apatite > garnet > kyanite, which characterizes deep burial of North Sea sandstones, has previously been simulated experimentally using fluids of pH 8 at room temperature. This suggests that high-temperature acidic pore-fluids may not have played a significant role in the development of secondary porosity in North Sea sandstones.
Morphological characterisation of portal myofibroblasts and hepatic stellate cells in the normal dog liver
Authors: IJzer Jooske , Roskams Tania , Molenbeek Ronald F , Ultee Ton , Penning Louis C , Rothuizen Jan , van den Ingh Ted SGAM
Published: November 2006

Background

Hepatic fibrosis is a common outcome of hepatic injury in both man and dog. Activated fibroblasts which develop myofibroblastic characteristics play an essential role in hepatic fibrogenesis, and are comprised of three subpopulations: 1) portal or septal myofibroblasts, 2) interface myofibroblasts and 3) the perisinusoidally located hepatic stellate cells (HSC). The present study was performed to investigate the immunohistochemical characteristics of canine portal myofibroblasts (MF) and HSC in the normal unaffected liver as a basis for further studies on fibrogenesis in canine liver disease.

Results

In the formalin-fixed and paraffin embedded normal canine liver vimentin showed staining of hepatic fibroblasts, probably including MF in portal areas and around hepatic veins; however, HSC were in general negative. Desmin proved to react with both portal MF and HSC. A unique feature of these HSC was the positive immunostaining for alpha-smooth muscle actin (α-SMA) and muscle-specific actin clone HHF35 (HHF35), also portal MF stained positive with these antibodies. Synaptophysin and glial fibrillary acidic protein (GFAP) were consistently negative in the normal canine liver. In a frozen chronic hepatitis case (with expected activated hepatic MF and HSC), HSC were negative to synaptophysin, GFAP and NCAM. Transmission electron microscopy (TEM) immunogold labelling for α-SMA and HHF35 recognized the positive cells as HSC situated in the space of Disse.

Conclusion

In the normal formalin-fixed and paraffin embedded canine liver hepatic portal MF and HSC can be identified by α-SMA, HHF35 and to a lesser extent desmin immunostaining. These antibodies can thus be used in further studies on hepatic fibrosis. Synaptophysin, GFAP and NCAM do not seem suitable for marking of canine HSC. The positivity of HSC for α-SMA and HHF35 in the normal canine liver may eventually reflect a more active regulation of hepatic sinusoidal flow by these HSC compared to other species.
Four-day antithrombin therapy does not seem to attenuate hypercoagulability in patients suffering from sepsis
Authors: Gonano Christopher , Sitzwohl Christian , Meitner Eva , Weinstabl Christian , Kettner Stephan C
Published: November 2006

Introduction

Sepsis activates the coagulation system and frequently causes hypercoagulability, which is not detected by routine coagulation tests. A reliable method to evaluate hypercoagulability is thromboelastography (TEG), but this has not so far been used to investigate sepsis-induced hypercoagulability. Antithrombin (AT) in plasma of septic patients is decreased, and administration of AT may therefore reduce the acquired hypercoagulability. Not clear, however, is to what extent supraphysiologic plasma levels of AT decrease the acute hypercoagulability in septic patients. The present study investigates the coagulation profile of septic patients before and during four day high-dose AT therapy.

Methods

Patients with severe sepsis were randomly assigned to receive either 6,000 IU AT as a bolus infusion followed by a maintenance dose of 250 IU/hour over four days (n = 17) or placebo (n = 16). TEG, platelet count, plasma fibrinogen levels, prothrombin time and activated partial thromboplastin time were assessed at baseline and daily during AT therapy.

Results

TEG showed a hypercoagulability in both groups at baseline, which was neither reversed by bolus or by maintenance doses of AT. The hypercoagulability was mainly caused by increased plasma fibrinogen, and to a lesser extent by platelets. Plasmatic coagulation as assessed by the prothrombin time and activated partial thromboplastin time was similar in both groups, and did not change during the study period.

Conclusion

The current study shows a distinct hypercoagulability in patients suffering from severe sepsis, which was not reversed by high-dose AT treatment over four days. This finding supports recent data showing that modulation of coagulatory activation in septic patients by AT does not occur before one week of therapy.

Trial registration: Current Control Trials ISRCTN22931023
ProCAT: a data analysis approach for protein microarrays
Authors: Zhu Xiaowei , Gerstein Mark , Snyder Michael
Published: November 2006

Protein microarrays provide a versatile method for the analysis of many protein biochemical activities. Existing DNA microarray analytical methods do not translate to protein microarrays due to differences between the technologies. Here we report a new approach, ProCAT, which corrects for background bias and spatial artifacts, identifies significant signals, filters nonspecific spots, and normalizes the resulting signal to protein abundance. ProCAT provides a powerful and flexible new approach for analyzing many types of protein microarrays.
Assessment of Seismic Fragility of Structures with Consideration of the Quality of Construction
Authors: Dimova Silvia L. , Negro Paolo
Published: November 2006

A method for the assessment of the seismic vulnerability of structures with consideration of the quality of construction is demonstrated on the example of single-story, industrial reinforced-concrete frames designed according to Eurocodes. Two experimental models of the prototype are considered: a structure erected under strict control of the workmanship and a structure with significant deficiencies in the arrangement of the reinforcement. Fragility analysis is performed for four damage states. The epistemic and aleatory uncertainties in the seismic demand and capacity for each damage state are determined. Among the considered different errors in the assembling of the reinforcement, the tying of the stirrups and the arrangement of the reinforcement in the beam-column joints are identified as critical deficiencies, which should be strictly controlled. The damage states of the studied structures are related to the European Macroseismic Scale and it is illustrated that the quality of construction does influence considerably the observed macroseismic intensity.
Performance of Two 18-Story Steel Moment-Frame Buildings in Southern California during Two Large Simulated San Andreas Earthquakes
Authors: Krishnan Swaminathan , Ji Chen , Komatitsch Dimitri , Tromp Jeroen
Published: November 2006

Using state-of-the-art computational tools in seismology and structural engineering, validated using data from the Mw=6.7 January 1994 Northridge earthquake, we determine the damage to two 18-story steel moment-frame buildings, one existing and one new, located in southern California due to ground motions from two hypothetical magnitude 7.9 earthquakes on the San Andreas Fault. The new building has the same configuration as the existing building but has been redesigned to current building code standards. Two cases are considered: rupture initiating at Parkfield and propagating from north to south, and rupture propagating from south to north and terminating at Parkfield. Severe damage occurs in these buildings at many locations in the region in the north-to-south rupture scenario. Peak velocities of 1 m.s−1 and 2 m.s−1 occur in the Los Angeles Basin and San Fernando Valley, respectively, while the corresponding peak displacements are about 1 m and 2 m, respectively. Peak interstory drifts in the two buildings exceed 0.10 and 0.06 in many areas of the San Fernando Valley and the Los Angeles Basin, respectively. The redesigned building performs significantly better than the existing building; however, its improved design based on the 1997 Uniform Building Code is still not adequate to prevent serious damage. The results from the south-to-north scenario are not as alarming, although damage is serious enough to cause significant business interruption and compromise life safety.
Vibration Frequencies of Woodframe Residential Construction
Authors: Kharrazi Mehdi H. K. , Ventura Carlos E.
Published: November 2006

Different methods of vibration measurement, such as ambient and forced vibration techniques, have been used in existing woodframe houses to determine fundamental frequency, but because of the highly nonlinear nature of this type of structural system, the reported results vary significantly. This paper discusses some of the differences of frequency values observed in various experimental studies, and identifies the source of these differences by relating the measured fundamental period to the level of shaking. The experimental results from different full-scale tests of woodframe houses and single wood shear walls are used in this paper to gain an improved understanding of the dynamic characteristics of this type of construction and to help explain the differences in results from ambient and forced vibration techniques. A simple equation to estimate forced vibration periods from ambient vibration periods is presented, and its possible application in engineering practice is discussed.
Code Approaches to Seismic Design of Masonry-Infilled Reinforced ConcreteFrames: A State-of-the-Art Review
Authors: Kaushik Hemant B. , Rai Durgesh C. , Jain Sudhir K.
Published: November 2006

Masonry infill (MI) walls are remarkable in increasing the initial stiffness of reinforced concrete (RC) frames, and being the stiffer component, attract most of the lateral seismic shear forces on buildings, thereby reducing the demand on the RC frame members. However, behavior of MI is difficult to predict because of significant variations in material properties and because of failure modes that are brittle in nature. As a result, MI walls have often been treated as nonstructural elements in buildings, and their effects are not included in the analysis and design procedure. However, experience shows that MI may have significant positive or negative effects on the global behavior of buildings and, therefore, should be addressed appropriately. Various national codes differ greatly in the manner effects of MI are to be considered in the design process from aseismic performance point of view. This paper reviews and compares analysis and design provisions related to MI-RC frames in seismic design codes of 16 countries and identifies important issues that should be addressed by a typical model code.
PLAC1 mRNA in Maternal Blood Correlates with Doppler Waveform in Uterine Arteries in Normal Pregnancies at the Second and Third Trimester
Authors: FARINA ANTONIO , CONCU MANUELA , BANZOLA IRINA , TEMPESTA ANNALISA , VAGNONI SONIA , GABRIELLI SANDRO , MATTIOLI MARA , CARINCI PAOLO , PILU GIANLUIGI , MORANO DANILA , RIZZO NICOLA
Published: November 2006

Abstract:  Doppler analysis of the uterine arteries is currently used for pre‐eclampsia (PE) screening. PLAC1 is a trophoblast‐specific gene, and it is known that in normal pregnancies, trophoblastic cells are released into the maternal circulation, where specific trophoblastic mRNA can be detected. In PE, as in women who eventually develop PE, an abnormal passage of fetal and placental cells is also present. In this study, we aimed to verify whether, in normal pregnancies, Doppler waveform of the uterine arteries correlates with PLAC1 mRNA concentrations. Thirteen cases of normal pregnancies at 37 weeks' gestation (23–41) were enrolled in the study. PLAC1 mRNA was extracted from 2 mL of blood by ABI PRISM 6100 nucleic acid Prep Station (Applied Biosystems, Foster City, CA) and quantitative reverse transcriptase‐polymerase chain reaction (RT‐PCR) analysis was performed by a PE 5700 Sequence detection system. Bulk RNA from normal placental tissue was used as the reference curve, and the amount of PLAC1 mRNA in the study samples was then expressed as the “relative amount” of weight of placental tissue (ng/mL). The uterine arterial mean resistance index (RI) and presence/absence of a dicrote waveform were calculated by using a 5 MHz transabdominal probe (Tecnos, ESAOTE) at the uterine cervico‐corporal junction. Doppler measurement was performed on the same day as blood collection. The median of the means of uterine arterial RI was 0.52 (0.39–0.68). RI of uterine arteries and PLAC1 mRNA were significantly correlated in a log‐linear regression (R2= 0.483, P= 0.024). Our data support that in normal pregnancy, the passage of trophoblast material into the maternal circulation is correlated with the quantitative measurement of uterine hemodynamics.
Circulating DNA and DNase Activity in Human Blood
Authors: TAMKOVICH SVETLANA N. , CHEREPANOVA ANNA V. , KOLESNIKOVA ELENA V. , RYKOVA ELENA Y. , PYSHNYI DMITRII V. , VLASSOV VALENTIN V. , LAKTIONOV PAVEL P.
Published: November 2006

Abstract:  The concentration of circulating DNA (cirDNA) and deoxyribonuclease activity in blood plasma of healthy donors and patients with colon or stomach cancer were analyzed. The concentration of DNA was measured using Hoechst 33258 fluorescent assay after the isolation by the glass–milk protocol. A 1‐kbp PCR product labeled with biotinylated forward and fluorescein‐labeled reverse primers was used as a substrate for DNase. DNase activity was estimated from the data of immunochemical detection of the nonhydrolyzed amplicon. The average concentration of cirDNA in the plasma of healthy donors was low (34 ± 34 ng/mL), and was accompanied with high DNase activity (0.356 ± 0.410 U/mL). The increased concentrations of cirDNA in blood plasma of patients with colon and stomach cancer were accompanied by a decrease in DNase activity below the detection level of the assay. The data obtained demonstrate that low DNase activity in blood plasma of cancer patients can cause an increase in the concentration of cirDNA.
Real‐Time Quantification of Human Telomerase Reverse Transcriptase mRNA in the Plasma of Patients with Prostate Cancer
Authors: DASÍ F. , MARTÍNEZ‐RODES P. , MARCH J.A. , SANTAMARÍA J. , MARTÍNEZ‐JAVALOYAS J.M. , GIL M. , ALIÑO S.F.
Published: November 2006

Abstract:  The aim of this study was to evaluate the potential diagnostic value of quantitative analysis of human telomerase reverse transcriptase (hTERT) mRNA in plasma for noninvasive diagnosis of prostate cancer (PCa). Expression levels of hTERT were analyzed by real‐time quantitative RT‐PCR in 68 patients showing elevated prostate‐specific antigen (PSA) levels and a control group of 44 healthy volunteers. Sensitivity and specificity were determined and compared to the corresponding PSA values. Median values for hTERT gene expression in the PCa patients (0.72 ng; range 0.01–12.86) were statistically significantly higher (P < 0.001) than in the control group (0.13 ng; 0.02–0.35). Patients with clinically confirmed prostatitis showed lower plasma hTERT expression than PCa patients (0.29; 0.01–66.07). At a cutoff value of 0.35 sensitivity and specificity for the diagnosis of PCa were 81% and 60%, respectively. We suggest that hTERT mRNA in plasma is a very specific and sensitive method that may aid to differentiate between malignant and nonmalignant prostate tissue and may be a useful marker (in combination with PSA) for early PCa diagnosis.
Circulating Nucleic Acids and Critical Illness
Authors: RAINER TIMOTHY H. , LAM NICOLE Y.L.
Published: November 2006

Abstract:  This article reviews some of the early work that has been performed to investigate the potential roles of circulating nucleic acids as prediction markers in acute illness and injury. Circulating DNA and RNA concentrations are elevated early in patients with trauma, stroke and ACS, and are generally highest in patients with a high risk of death. Circulating nucleic acids may be useful markers for the evaluation and risk‐stratification of such patients.
MALDI‐TOF Mass Spectrometry for Quantitative, Specific, and Sensitive Analysis of DNA and RNA
Authors: DING CHUNMING , LO YUK MING DENNIS
Published: November 2006

Abstract:  Cell‐free fetal DNA and RNA released into the maternal circulation offer new opportunities to study fetal and pregnancy‐associated abnormalities. Similarly, tumor cells can release cell‐free DNA and RNA into the peripheral circulation, and these cell‐free DNA and RNA can be used for cancer diagnosis, monitoring, and prognosis. However, these DNA and RNA often exist at very low concentrations (for fetal DNA, ∼20 genome‐equivalents (G.E.)/mL of plasma in the first trimester). The analysis is further complicated by the predominant amount of blood cell‐derived DNA and RNA. MALDI‐TOF mass spectrometry can provide quantitative, specific, and sensitive analysis of DNA and RNA, and thus may be a useful technology for the field.
“The Prose of the World”: Romanticism, the Nineteenth Century, and the Reorganization of Knowledge
Authors: Rajan Tilottama
Published: November 2006

Tilottama Rajan is Canada Research Chair in English and Theory, and former director of the Centre for Theory and Criticism, at the University of Western Ontario. She is author of three books, most recently Deconstruction and the Remainders of Phenomenology: Sartre, Derrida, Foucault, Baudrillard (2002), and coeditor of four collections, most recently Idealism without Absolutes: Philosophy and Romantic Culture (2004). She is working on a book about encyclopedic thought and the organization of knowledge from German idealism to deconstruction, as well as on a book about Romantic narrative.
Juxtaposed Polycomb complexes co-regulate vertebral identity
Authors: Kim Se Young , Paylor Suzanne W. , Magnuson Terry , Schumacher Armin
Published: November 2006

Best known as epigenetic repressors of developmental Hox gene transcription, Polycomb complexes alter chromatin structure by means of post-translational modification of histone tails. Depending on the cellular context, Polycomb complexes of diverse composition and function exhibit cooperative interaction or hierarchical interdependency at target loci. The present study interrogated the genetic, biochemical and molecular interaction of BMI1 and EED, pivotal constituents of heterologous Polycomb complexes, in the regulation of vertebral identity during mouse development. Despite a significant overlap in dosage-sensitive homeotic phenotypes and co-repression of a similar set of Hox genes, genetic analysis implicated eed and Bmi1 in parallel pathways, which converge at the level of Hox gene regulation. Whereas EED and BMI1 formed separate biochemical entities with EzH2 and Ring1B, respectively, in mid-gestation embryos, YY1 engaged in both Polycomb complexes. Strikingly, methylated lysine 27 of histone H3 (H3-K27), a mediator of Polycomb complex recruitment to target genes, stably associated with the EED complex during the maintenance phase of Hox gene repression. Juxtaposed EED and BMI1 complexes, along with YY1 and methylated H3-K27, were detected in upstream regulatory regions of Hoxc8 and Hoxa5. The combined data suggest a model wherein epigenetic and genetic elements cooperatively recruit and retain juxtaposed Polycomb complexes in mammalian Hox gene clusters toward co-regulation of vertebral identity.
Nonlethal Sampling of Sunfish and Slimy Sculpin for Stable Isotope Analysis: How Scale and Fin Tissue Compare with Muscle Tissue
Authors: Kelly Maureen H. , Hagar William G. , Jardine Timothy D. , Cunjak Richard A.
Published: November 2006

We found that the sampling of tissues that do not result in the death of the fish, such as scale and fin tissue, may be substituted for muscle tissue in stable isotope analysis (SIA) of fishes. Comparisons were made between the values of δ13C and δ15N found in muscle tissue with the corresponding scale tissue of three sunfish species (bluegill Lepomis macrochirus, pumpkinseed L. gibbosus, and redbreast sunfish L. auritus) and with caudal fin tissue of slimy sculpin Cottus cognatus. The fish showed strong linear correlation in δ13C values between their nonlethally sampled scale or fin tissue and their muscle tissue (combined sunfish: r = 0.97; slimy sculpin: r = 0.84). Sunfish δ13C values were higher in scale tissue than in muscle tissue and required a correction factor for converting the scale values to the muscle values (regression equation: y = 1.1673x + 1.0531). Slimy sculpin δ13C fin and muscle values were similar and did not require a correction factor. The correlation of δ15N values between the tissues was also strong in both sunfish (r = 0.94) and slimy sculpin (r = 0.90). A correction factor was needed to convert δ15N values from scale to muscle in the three sunfish species (y = 0.8504x + 2.6698) and from fin to muscle in slimy sculpin (y = 1.2658x − 3.3234). Results of this study and other literature support the use of nonlethally sampled tissues for SIA of fish. These methods may be used for investigations of rare and endangered species and also allow for analysis of archived fish scales.
Historical Changes in Abundance of Floating-Leaf and Emergent Vegetation in Minnesota Lakes
Authors: Radomski Paul
Published: November 2006

To assess the consequences of shoreline development, whole-lake vegetation abundance of dense floating-leaf and emergent vegetation in 100 north-central Minnesota lakes was estimated from aerial photographs for selected years between 1939 and 2003. Lakes were randomly selected from three shoreland development classifications, which define statewide minimum shoreline development standards for Minnesota. The three classes, in order of increasing restrictions for development, are general development, recreational development, and natural environment. Image analysis techniques were used to estimate vegetation abundance (percent cover). Shoreline development varied by shoreland development class. Floating-leaf and emergent vegetative cover (percent of lake surface area) was significantly affected by development. Increases in shoreline development, indexed by dock sites per shoreline kilometer, reduced plant cover. A linear mixed-effects model estimated that in 2003, the mean floating-leaf and emergent vegetation cover loss from development was 6% for natural-environment lakes, 14% for recreational-development lakes, and 17% for general-development lakes. Total vegetation cover loss for north-central Minnesota lakes was estimated at 15%. Shoreline regulatory policies may need to be changed or riparian owner incentive programs added to address cumulative impacts to fish and wildlife habitat.
Radiation Recall Dermatitis with Cefotetan: A Case Study
Authors: Ayoola Ayodele , Lee Young Joo
Published: November 2006

Radiation recall dermatitis (RRD) is an inflammatory skin reaction that occurs in a previously irradiated body part following drug administration. This phenomenon may occur from days to years following exposure to ionizing radiation. The case of a 54-year-old Caucasian woman who was initially treated with external-beam radiation to the right thoracic region following the diagnosis of a poorly differentiated squamous cell carcinoma of the right lung is reported. She received four cycles of consolidated chemotherapy with docetaxel and carboplatin. Four months later, she was admitted to the hospital for acute cholecystitis and was placed on cefotetan. She developed a tender, erythematous rash on the posterior region of her right thorax 48 hours later. The drug was withdrawn, supportive care was instituted, and the patient subsequently improved. RRD should be suspected in patients who develop an erythematous rash in a previously irradiated region. To our knowledge this entity has not been associated with cefotetan previously.
Bone Loss and Fracture Risk Associated with Cancer Therapy
Authors: Guise Theresa A.
Published: November 2006

Learning Objectives

After completing this course, the reader will be able to: Identify cancer therapies associated with bone loss.Explain the unique aspects of cancer therapy–associated bone loss.Screen for and manage bone loss in cancer patients.Describe the safety profile of bisphosphonate drug treatment.

Access and take the CME test online and receive 1 AMA PRA Category 1 Credit™ at CME.TheOncologist.com

Background. Cancer patients experience osteoporosis resulting from accelerated loss of bone mineral density (BMD) caused by their treatment. Such bone loss greatly increases the risk for fracture and can have other serious effects on quality of life.

Methods. In the current report, the author focuses on studies of cancer therapy-associated bone loss, its prevalence and pathogenesis, and resulting clinical impact. Options for management and prevention are also reviewed, including treatment guidelines where available.

Results. A variety of cancer therapies, including hormonal therapy, chemotherapy, and glucocorticoids, affect gonadal hormone production, which increases bone resorption and decreases BMD. Such bone loss occurs more rapidly and to a greater degree than normal age-related osteoporosis, increases the risk for fracture and other morbidities, and decreases survival. Regular BMD screening and early intervention can prevent further decline in bone density and bone quality. Pharmacologic therapy with oral and i.v. bisphosphonates has been shown to slow bone loss in patients receiving cancer therapy, and the i.v. bisphosphonate zoledronic acid can increase BMD in patients with cancer treatment-related bone loss. Lifestyle changes, including supplementation with calcium and vitamin D, diet, and proper exercise, can also slow the rate of bone loss.

Conclusions. Bone loss associated with various cancer therapies significantly affects bone health. Early initiation of bisphosphonates, when indicated, and lifestyle modification can improve patient outcomes. Education of patients and health care professionals regarding the importance of this complication and effective treatment options is essential.
An Evaluation of Methods and Available Software for Seismic Refraction Tomography Analysis
Authors: Sheehan Jacob R. , Doll William E. , Mandell Wayne A.
Published: November 2006

Seismic refraction tomography is an alternative to conventional seismic refraction analysis methods. While the limitations and potential pitfalls of conventional refraction methods are well-known the same is not true for refraction tomography. As refraction tomography becomes more widely used, the need to know and understand its capabilities as well as its limitations becomes more critical. In this study we created eight representative models for use in evaluating three commercially available codes as well as refraction tomography in general. These models range from simple two-layer or dipping-layer problems to more complicated models designed to represent features of karst terrains. We demonstrate quantitatively and qualitatively that all three codes perform at a similar level, although each has strengths and weaknesses. Refraction tomography performs well in many situations where conventional methods fail, e.g., where lateral or vertical gradients compose a significant component of the velocity structure.
Detecting Anomalous Inclusions in Soil Profiles: Encouraging the Use of Geophysics to Solve Engineering Problems Editorial
Authors: Luke Barbara , Calderón-Macías Carlos
Published: November 2006

Geotechnical site investigations often do not take full advantage of geophysical methods. As examples, when delineating cemented strata and when detecting shallow cavities, investigations can be enhanced greatly for low additional cost by incorporating seismic surface-based measurements.
Shear-wave Velocity Profile for Holocene Sediments Measured from Microtremor Array Studies, SCPT, and Seismic Refraction
Authors: Asten Michael W. , (Bill) Stephenson W. R. , Davenport Peter N.
Published: November 2006

The microtremor method was trialed on soft Holocene sediments overlying glacial gravels near the Hutt River, Wellington New Zealand. A triangular four-station array of radius [Formula: see text], processed using a modified spatial autocorrelation (SPAC) method was sufficient to establish shear velocity for sediments and gravels, and a thickness of [Formula: see text] for the soft sediments. The interpretation was performed blind to geological and geophysical data, and subsequent comparison with seismic cone penetrometer and seismic refraction data shows the accuracy from the SPAC interpretation to be better than 5%. Interpretation of horizontal: vertical spectral ratio data assists with estimates of thickness of the glacial gravels (hundreds of meters) but accuracy in thickness is poor, perhaps due to uncertainty in the 2D nature of the base of the gravel-filled glacial valley.
Active-passive Array Surface Wave Inversion and Comparison to Borehole Logs in Southeast Missouri
Authors: Malovichko Alexei A. , Anderson Neil L. , Malovichko Dmitriy A. , Shylakov Denis Yu. , Butirin Pavel G.
Published: November 2006

In May 2002, both active- and passive-source surface wave data were acquired using 4-channel arrays at six selected bridge sites in southeast Missouri. Processing of acquired data (increase of signal-to-noise ratio, estimation of phase velocities) was carried out and dispersion curves of Rayleigh wave phase velocities were constructed. Each fundamental mode dispersion curve was then inverted by linearised optimization to a layered shear-wave velocity profile to depths of up to [Formula: see text]. The estimated shear-wave velocity profiles were compared to other geotechnical data that had been previously acquired at each test site for the Missouri Department of Transportation (MoDOT) including cone penetrometer test (CPT) data, borehole lithologic control, seismic cone penetrometer test (SCPT) shear-wave data and cross-borehole (CH) shear-wave data. The surface wave models, although smoother than the destructive test logs, are accurate and consistent (17% average difference with CH results on two sites), and, moreover, provide information on lithology above the water table and at depths beyond the SCPT and CH limitations, in a more logistically-easier and cost-effective manner.
Analyzing and Filtering Surface-Wave Energy By Muting Shot Gathers
Authors: Ivanov Julian , Park Choon B. , Miller Richard D. , Xia Jianghai
Published: November 2006

Accurate estimation of the fundamental-mode dispersion curve is the most critical processing step of many shallow surface-wave methods. Use of multichannel analysis of surface waves (MASW), has proven very effective in separating different dispersive events that share the same seismic-frequency range. Yet, under certain circumstances, even when using such a data-redundant method, it may not be possible to separate the fundamental mode of the surface waves from higher modes. Dominant higher surface-wave modes, together with body- and guided waves, can impede the estimation of the fundamental mode. This is especially true when relatively short spread lengths are required for the survey for reasons such as higher lateral-resolution demands or presence of noise at the far offsets. A simple multichannel processing technique that mutes the interfering seismic waves in the shot records (offset-time [Formula: see text] domain) can be used to analyze and filter noisy surface-wave modes and thus significantly improve the range and resolution of multimodal dispersion curves in the phase-velocity-frequency domain. This is demonstrated on both synthetic and real shot gathers. One shortcoming of the muting method is the estimation of artificially high phase-velocity values at low frequencies. This artifact can be countered by employing dispersion-curve estimation in the same low-frequency range using the unmuted shot records. The proposed muting technique can be beneficial not only for the evaluation of the fundamental mode of the Rayleigh wave, but also for other types of dispersive seismic energy, such as higher Rayleigh-wave modes, Lamb, guided, and Love waves.
Resolution of 3-D Electrical Resistivity Images from Inversions of 2-D Orthogonal Lines
Authors: Gharibi Mehran , Bentley Laurence R.
Published: November 2006

Three-D electrical resistivity imaging (ERI) using sets of orthogonal of 2-D survey lines provides an efficient and cost effective tool for site characterization in environmental and engineering investigations. A 3-D survey design using sparse sets of lines reduces the survey time at the expense of the resolution. The effects of line spacing on the resolution of 3-D electrical resistivity images were investigated using numerical modeling with synthetic and field data for two standard configurations, dipole-dipole and Wenner arrays. Synthetic data studies indicate that dipole-dipole configuration produces a more accurate map of the subsurface than the Wenner configuration. A severely under-sampled 3-D survey could result in introducing small-scale shallow spurious artifacts at the surface of the resistivity model caused by the projection of the anomalies located in the deeper parts of the model. Results from inversion of the real and synthetic data showed that lines should be separated by no more than four electrode spacings and, if the shallow subsurface is important, by no more than two electrode spacings. The dipole-dipole array performs better than the Wenner array, but it requires more acquisition effort and is more sensitive to noise. These modeling results provide insight into quantitative survey designs that produce sufficient information to meet survey objective within a given field efforts.
Airborne Electromagnetic Mapping for Buried Quaternary Sands and Gravels in Northeast British Columbia, Canada
Authors: Best Melvyn E. , Levson Victor M. , Ferbey Travis , McConnell Doug
Published: November 2006

An airborne electromagnetic (AEM) survey using the Fugro RESOLVE™ system was conducted over a known, buried sand and gravel deposit in northeast British Columbia, Canada to determine its effectiveness for mapping similar deposits in the area. The rarity of gravel deposits in this region provides a significant economic constraint for developing oil and gas infrastructure. Topographic relief is minimal and the area is overlain by organic materials, clay-rich tills, and glaciolacustrine sediments. Traditional exploration methods, such as airphoto interpretation, are therefore ineffective for locating these buried deposits. The buried deposit appears as a resistivity high on the apparent resistivity maps, particularly the [Formula: see text] map. The resistivity high covers a larger area than that defined initially by test pitting. Trenching within this extended zone verified the presence of sand and gravel. Other resistive features in the region were identified by the survey and one of these was confirmed by recent test pitting to be a large sand and gravel occurrence. No surface indications of sand and gravel were evident over any of these occurrences. The cross sections indicated these sand and gravel occurrences have resistivity values greater than [Formula: see text], often greater than [Formula: see text], whereas the surrounding till has resistivity values between 5 and [Formula: see text]. The airborne survey proved to be a highly successful method of locating sand and gravel deposits in this area of British Columbia that could be widely used in other plains regions with similar geological settings.
Electromagnetic Properties of Cemented Paste Backfill
Authors: Klein Katherine , Simon Dragana
Published: November 2006

The effect of specimen composition on the physicochemical processes in cemented paste backfill is studied using small perturbation electromagnetic waves. The factors that are tested include binder type and content, selected chemical admixtures (superplasticizers), mineral additives (e.g., fly ash), and pore fluid chemistry (e.g., ionic concentration and pH). Two measurement techniques are used: a two-electrode capacitor-type system at low frequencies [Formula: see text] and an open-ended coaxial termination probe at high frequencies [Formula: see text]. The electromagnetic measurements are sensitive to changes in the CPB composition. The temporal variations in the effective conductivity reflect the various hydration stages, while the decrease in the real relative permittivity with time is due to a reduction in free water content.
Th∕K and Th∕U Ratios from Spectral Gamma-Ray Surveys Improve the Mapped Definition of Subsurface Structures
Authors: Ruffell A. , McKinley J. M. , Lloyd C. D. , Graham C.
Published: November 2006

Spectral gamma-ray data can be obtained by non-destructive, automated, rapid and inexpensive survey methods. Previous studies utilise only total count, or total count as well as K, U and Th data. This work examines the use of [Formula: see text] and [Formula: see text] ratios to define the subsurface extent of partially-buried features at the centimeter to meter scale. On-site results are presented from two case studies as two-dimensional cross-sections. Changes in [Formula: see text] and [Formula: see text] ratios coincide with the known location of buried structures to within [Formula: see text] horizontal resolution. Gradual changes in total count, K, U and Th measurements give a lower horizontal accuracy of [Formula: see text]. Grids of data were manipulated in ArcGIS™ using a thin plate spline function to maximise information use and provide ‘easy to interpret’ maps of the survey areas. Unlike total count or individual element maps, [Formula: see text] and [Formula: see text] ratio maps can be compared to the known location of subsurface structures, vindicating the use of ratio cross-sections and maps in archaeological, geotechnical and forensic applications. It is concluded that the capacity to observe sub-surface features is enhanced through the use of [Formula: see text] and [Formula: see text] ratios.
Increasing quantity of water: perspectives from rural households in Uganda
Authors: Sugita Elli W.
Published: November 2006

Community involvement, low-technology and affordability are some of the important concepts in increasing water access to the rural poor. This study examines water-collection behavior of households in a rural area without piped-water in the Mbale district, Uganda. It tests for the determinants of water quantity available at the household level and suggests measures to increase water quantity. The results of multiple regression analysis showed that the amount of water per capita per day increased by 0.86 liters (L) (11% of the current average water quantity of 7.87 l) with the addition of one 20-L jerry can to a household. If a household has a sheet-metal roof (facilitating rainwater collection) and also uses a bicycle to carry water, the amount of water per capita increased by 2.08 L (26%), compared to not having both factors or having only one. This result implies that the amount of water at the household level can be increased by means other than constructing new water sources.
Privatization model for water enterprise in Kenya
Authors: K'Akumu O. A.
Published: November 2006

The world over, the role and eligibility of the state in the provision of water supply is increasingly coming into question. Policy makers and analysts are advocating the abdication of the state in favour of private participation. This is expected to bring with it a host of benefits to all the stakeholders concerned. Kenya is one of the developing countries that have endeavoured to privatize their water sectors. Kenya has done this by enactment and implementation of the Water Act of 2002. The paper carries out an analysis of the water institutions being created under the new legislation. This has been done against conventional policy and conceptual frameworks. Overall, the institutional set-up is found to be public sector-oriented rather than private sector-oriented. Recommendations are made for legislative review for mainstreaming private sector participation.
Evaluation of catheter-associated urinary tract infections and multi–drug-resistant Escherichia coli isolates from the urine of dogs with indwelling urinary catheters
Authors: Ogeer-Gyles Jennifer , Mathews Karol , Weese J. Scott , Prescott John F. , Boerlin Patrick
Published: November 2006

Objective—To determine the frequency of urinary tract infections (UTIs) in dogs with indwelling urinary catheters in an intensive care unit (ICU) and the frequency of multi–drug-resistant (MDR) Escherichia coli UTIs in those dogs.

Design—Prospective study.

Animals—All dogs in the ICU with an indwelling urinary catheter from January 2003 through December 2003.

Procedures—Urine samples and rectal swab specimens were collected at admission and every 3 days until discharge from the hospital. Escherichia coli isolates from urine samples and rectal swab specimens and those from dogs that were temporally or spatially associated with dogs with MDR E coli UTIs underwent antimicrobial susceptibility testing. Pulsed-field gel electrophoresis was performed on MDR isolates from urine and rectal swab specimens.

Results—Urinary catheters were placed in 137 dogs. Twenty-six UTIs were diagnosed, 15 on the day of admission and 11 after 3 or more days of catheterization. Of 12 dogs with E coli UTIs, 6 were infected at admission and 6 acquired the infection in the ICU. Two MDR E coli UTIs were detected, 1 of which was acquired in the ICU. One MDR E coli urinary isolate had an electrophoresis pattern similar to that of rectal isolates from the same dog. Urinary E coli isolates were most frequently resistant to ampicillin and cephalothin.

Conclusions and Clinical Relevance—The ICU-acquired MDR E coli UTI likely originated from the dog's intestinal flora during hospitalization. Dogs that have been referred from a community practice may have MDR E coli UTIs at the time of admission.
A solid-phase dot assay using silica/gold nanoshells
Authors: Khlebtsov Boris , Dykman Lev , Bogatyrev Vladimir , Zharov Vladimir , Khlebtsov Nikolai
Published: November 2006

We report on the first application of silica-gold nanoshells to a solid-phase dot immunoassay. The assay principle is based on staining of a drop (1 µl) analyte on a nitrocellulose membrane strip by using silica/gold nanoshells conjugated with biospecific probing molecules. Experimental example is human IgG (hIgG, target molecules) and protein A (probing molecules). For usual 15-nm colloidal gold conjugates, the minimal detectable amount of hIgG is about 4 ng. By contrast, for nanoshell conjugates (silica core diameter of 70 nm and gold outer diameter of 100 nm) we have found significant increase in detection sensitivity and the minimal detectable amount of hIgG is about 0.5 ng. This finding is explained by the difference in the monolayer particle extinction.
Mixed micelles of hexadecylpyridinium bromide + tetradecyltrimethylammonium bromide in aqueous glycol oligomers
Authors: Bakshi Mandeep Singh , Kaur Gurjeet
Published: November 2006

Conductances of hexadecylpyridinium bromide (HPyBr) + tetradecyltrimethylammonium bromide (TTAB) mixtures over the entire mole fraction range of HPyBr (αHPyBr) were measured in pure water as well as in the presence of various aqueous ethylene glycol oligomers containing 10 and 30 wt% of each additive in their respective binary mixtures at 30°C. Each conductivity curve shows two breaks corresponding to two critical micelle concentrations (cmc; C1 and C2 over the whole mole fraction range of HPyBr + TTAB mixtures except in the presence of pure HPyBr and TTAB, where a single break was observed. From the conductivity data, various micellar paramelers in the absence and presence of glycol additives were computed. A variation in the micellar parameters in the presence of additive showed that additive introduction mainly influence the medium properties and therefore the micellar properties. However, no significant micelle‐glycol interactions were observed even with an increase in the number of repeating units from ethylene glycol to polyethylene glycol 600. The mixing behavior of HPyBr + TTAB is close to nonideal and is identical in pure water and in the presence of various glycols. This has been attributed to the presence of synergistic interactions between unlike monomers at C1 that are not influenced even by the presence of additives. The appearance of the second cmc is mainly attributed to structural transitions of the mixed micelles at C1 with a further increase in surfactant concentration.
Simplified synthesis of oligoethylene glycols
Authors: Zada Anat , Avny Yair , Zilkha Albert
Published: November 2006

Simple economical syntheses in good yield of octa‐, nona‐, and undecaethylene glycols were developed based on a coupling methodology whereby monobenzyl trior tetraethylene glycols were chain‐extended either by coupling them together in the presence of tosyl chloride or through reaction with α,ω‐ditosyl triethylene glycol in dioxane in the presence of powdered KOH. The α,ω‐O‐benzyl‐protecting groups were removed by catalytic hydrogenolysis.