bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fetal cardiac output, distribution to the placenta and impact of placental compromise
Authors: Kiserud T. , Ebbing C. , Kessler J. , Rasmussen S. 
Published: July 2006

AbstractObjectivesIntrauterine growth restriction is a common clinical problem, but the underlying hemodynamic changes are not well known. Our aim was to determine the normal distribution of fetal cardiac output to the placenta during the second half of pregnancy, and to assess the changes imposed by growth restriction with various degrees of placental compromise.MethodsA cross‐sectional study of 212 low‐risk pregnancies with a gestational age of 18–41 weeks constituted the reference population. A second group of 64 pregnancies with an estimated fetal weight ⩽ 2.5th percentile constituted the study group. Ultrasound measurements of inner diameters and velocities at the fetal left and right ventricular outlets and intra‐abdominal umbilical vein were used to determine combined left and right cardiac output (CCO) and the fraction distributed to the placenta. Placental compromise was graded according to umbilical artery waveform: pulsatility index normal, > 97.5th percentile, or absent/reversed end‐diastolic velocity. Regression analysis and Z‐score (SD‐score) statistics were used to establish normal ranges and to compare groups.ResultsDuring gestational weeks 18–41 the normal CCO/kg was on average 400 mL/min/kg and the fraction directed to the placenta was on average 32%, while after 32 weeks it was 21%. In intrauterine growth restriction the CCO/kg was not significantly different, but the fraction to the placenta was lower (P < 0.001). This effect was more pronounced in severe placental compromise (P < 0.001).ConclusionsNormally, one third of the fetal CCO is distributed to the placenta in most of the second half of pregnancy, and one fifth near term. In placental compromise this fraction is reduced while CCO/kg is maintained at normal levels, signifying an increased recirculation of umbilical blood in the fetal body. Copyright © 2006 ISUOG. Published by John Wiley & Sons, Ltd.
Performance analysis of coded cooperation diversity in wireless networks
Authors: Zummo Salam A. 
Published: July 2006

AbstractDiversity is an effective technique in enhancing the link quality and increasing network capacity. When multiple antennas cannot be used in mobile units, user cooperation can be employed to provide transmit diversity. In this paper, we analyze the error performance of coded cooperation diversity with multiple cooperating users. We derive the end‐to‐end bit error probability of coded cooperation (averaged over all cooperation scenarios). We consider different fading distributions for the interuser channels. Furthermore, we consider the case of two cooperating users with correlated uplink channels. Results show that more cooperating users should be allowed under good interuser channel conditions, while it suffices to have two cooperating users in adverse interuser conditions. Furthermore, under bad interuser conditions, more cooperating users can be accommodated as the fading distribution becomes more random. Copyright © 2006 John Wiley & Sons, Ltd.
Two-fluid tokamak equilibria with reversed magnetic shear and sheared flow
Authors: POULIPOULIS G. , THROUMOULOPOULOS G. N. , TASSO H. 
Published: July 2006

AbstractThe aim of the present work is to investigate tokamak equilibria with reversed magnetic shear and sheared flow, which may play a role in the formation of internal transport barriers (ITBs), within the framework of the two-fluid model in cylindrical geometry. The study is based on exact self-consistent solutions by means of which the impact of the magnetic shear, s, and the ‘toroidal’ (axial) and ‘poloidal’ (azimuthal) ion velocity components, viz and viθ, on the radial electric field, Er, its shear, |dEr/dr|, and the shear of the E×B velocity, ωE×B≡|d/dr(E× B/B2)|, is examined. For a wide parametric regime of experimental concern it turns out that the contributions of the viz, viθ and pressure gradient (∇ Pi) terms to Er, |Er′| and ωE×B are of the same order of magnitude. The contribution of the ∇ Pi term is missing in the framework of magnetohydrodynamics (MHD) (G. Poulipoulis et al. 2004 Plasma Phys. Control. Fusion46, 639). The impact of s on ωE×B through the ∇ Pi term is stronger than that through the velocity terms; in particular for constant Bz the ion pressure gradient contribution to ωE×B at the point where dEr/dr=0 scales as (1−s)(2−s), whereas the ion flow contributions to ωE×B scale as (1−s). The results indicate that, like MHD, the magnetic shear and the sheared toroidal and poloidal velocities act synergetically in producing electric fields and therefore ωE×B profiles compatible with the ones observed in discharges with ITBs; owing to the ∇ Pi term, however, the impact of s on Er, |Er′| and ωE×B is stronger than that in MHD.
Modified Korteweg–de Vries theory of non-monotonic double layers in multi-species plasma
Authors: KIM T. H. , KIM S. S. , KIM H. Y. , HWANG J. H. 
Published: July 2006

AbstractThe analytic solution for the time stationary non-monotonic double layers in multi-species plasma is presented. This solution is the analytic extension of the monotonic double layer and the solitary hole. We have derived the modified Korteweg–de Vries equation in plasmas, taking account of negative ion effects. The effects of negative ion and density on the properties of the non-monotonic double layer are discussed.
Melanoma of the Nose: Prognostic Factors, Three‐Dimensional Histology, and Surgical Strategies
Authors: Jahn Verena , Breuninger Helmut , Garbe Claus , Maassen Marcus M. , Moehrle Matthias 
Published: July 2006

AbstractObjectives: The prominent position of the nose in the face accounts for its constant exposure to sunlight and thus its high incidence of malignant involvement. The aim of this prospective study was to define prognostic factors for nasal melanomas and to evaluate surgical strategies.Methods: Forty‐five patients with stage I/II melanoma were included. Malignant melanomas of the nose represented 0.8% of stage I/II cutaneous melanoma and 5.3% of head and neck melanoma (1983–2004). The median tumor thickness was 0.75 mm. Twenty‐two of 33 Lentigo maligna melanomas (LMM) underwent three‐dimensional (3D) histology in paraffin technique (i.e., micrographic surgery).Results: The 5 year disease‐specific survival rate was 96%, and the 5 year recurrence‐free survival rate was 93%. There were no statistically significant risk factors in the univariate analysis. LMMs that were removed with accompanying 3D histology were thinner than other histologic types (median 0.75 vs. 1.55 mm). Compared with conventional histology, using 3D histology made it possible to reduce the excision margins (median 5 vs. 10 mm). There was one lymph node recurrence after LMM with 3D histology. Of five sentinel lymph node biopsies (SLNB) there was no positive SLNB and no recurrence.Conclusion: This is the largest study of nasal melanomas so far. Excision of LMM using 3D histology allowed the reduction of excision margins for better cosmesis and function. Our results do not permit conclusions regarding the prognostic impact of SLNB.
Lipoplex and LPD Nanoparticles for In Vivo Gene Delivery
Authors: Shyh-Dar Li , Song Li , Leaf Huang 
Published: July 2006

INTRODUCTIONLipoplex (cationic liposome-DNA complex) is formed via electrostatic interaction of anionic nucleic acids with cationic liposomes. A thin film of lipids is dried on the bottom of a glass tube and rehydrated in an aqueous solution. The resulting liposome suspension is passed through polycarbonate filters of desired pore size. This protocol also describes the preparation, physical properties, and biological activity of liposome-polycation-DNA (LPD) nanoparticles. The LPD nanoparticles contain a highly condensed DNA core surrounded by lipid bilayers with an average size of ~100 nm. The nanoparticle complex is injected into mice, and expression of the transfected DNA is monitored with an appropriate assay.
Soil quality around a solid waste dumpsite in Port Harcourt, Nigeria
Authors: Ideriah Tubonimi J. K. , Omuaru Victor O. T. , Adiukwu Patricia U. 
Published: July 2006

AbstractThe levels of soil parameters and selected heavy metals around a solid waste dumpsite receiving untreated wastes from all sources and a control site within Port Harcourt, Nigeria have been examined. Top soil (0–15 cm) and sediment samples were collected and analysed for pH value, particle size, total nitrogen, potassium, available phosphorus, organic matter, effective cation exchange capacity, cadmium, nickel and lead using standard methods. The results showed that the waste dump contributed to the high levels of nutrients and heavy metals. The dry season mean concentrations were: organic matter (5.28 ± 1.34% or 132,422.4 kg ha−1), K (1.60 ± 0.52 meq per 100 g), N (0.09 ± 0.06% or 2257.2 kg ha−1), Av.P (15.11 ± 7.57 μg g−1), Cd (1.34 ± 0.72 μg g−1), Ni (4.10 ± 1.63 μg g−1) and Pb (38.85 ± 22.18 μg g−1) while the wet season mean concentrations were organic matter (5.46 ± 1.39% or 136,936.8 kg ha−1), K (2.79 ± 0.81 meq per 100 g), N (0.10 ± 0.05% or 2508 kg ha−1), Av.P (9.22 ± 2.69 μg g−1), Cd (1.72 ± 1.22 μg g−1), Ni (14.95 ± 14.94 μg g−1) and Pb (53.50 ± 40.09 μg g−1). There was efficient mineralization process in the area. The texture of soil on the main dumpsite was loamy sand, which suggests that the ground water in the area is susceptible to contamination by surface pollutants. The texture of soil at the control site is sandy loam while sediment has the textural class of sand. Decomposed organic materials and agricultural activities influenced the texture of soils. The soils from the main dump and sediment were slightly alkaline while the control soil was moderately acidic. In both seasons, a significant variation exists (P < 0.05) between the metal concentrations in soil at the main dump and those in the sediments with a positive correlation (r = 0.572149) in the wet season and (r = 0.956647) in the dry season. The presence of liming materials and activities of microorganisms on the waste dump increased the pH of the soils. The accumulation of nutrients results in the luxuriant growth of plants/crops on the waste dump.
Transaction costs of community‐based forest management: empirical evidence from Tanzania
Authors: Meshack Charles K. , Ahdikari Bhim , Doggart Nike , Lovett Jon C. 
Published: July 2006

AbstractLevels of transaction costs in community‐based forest management (CBFM) in four communities adjacent to the Ambangulu mountain forests of the north‐east of Tanzania were assessed through questionnaire responses from 120 households. Costs and benefits of CBFM to the rich, medium and poor groups of forest users were estimated. Costs of CBFM were participation in forest monitoring and time spent in meetings. Benefits included forest products consumed at household level. Transaction costs relative to benefits for CBFM were found to be higher for poorer households compared with medium income and richer households. Higher income groups obtained the most net benefits followed by medium and poorer households. Community involvement in forest management may lower the transaction costs incurred by government, but a large proportion of these costs are borne by poorer members of the community. Transaction costs are critical factors in the success or failure of CBFM and need to be incorporated into policies and legislation related to community‐based natural resource management.
Effects of three cytochrome P450 inhibitors, ketoconazole, fluconazole, and paroxetine, on the pharmacokinetics of lasofoxifene
Authors: Ouellet D. , Bramson C. , Roman D. , Remmers A. E. , Randinitis E. , Milton A. , Gardner M. 
Published: July 2006

AimsTwo studies were conduced to assess the effects of ketoconazole, a CYP3A4/5 inhibitor; fluconazole, a CYP2C9 inhibitor; and paroxetine, a CYP2D6 inhibitor, on lasofoxifene pharmacokinetics.MethodsThe first parallel group study was conducted in 45 healthy postmenopausal women (15 per group) to compare the pharmacokinetics of a single dose of lasofoxifene (0.25 mg) administered alone and in combination with ketoconazole (400 mg daily × 20 days) or fluconazole (400 mg daily × 20 days). Lasofoxifene was administered on day 2 and blood samples were collected serially for up to 456 h postdose (20 days). The second study enrolled 20 healthy postmenopausal women (10 per group) to compare the pharmacokinetics of a single dose of lasofoxifene (0.25 mg) alone and in combination with paroxetine (30 mg qd × 21 days). Lasofoxifene was given on day 8 of paroxetine treatment and blood samples were collected serially for up to 336 h postdose.ResultsAll subjects completed the study and the treatments were well tolerated. LasofoxifeneCmaxand AUC ratios [90% confidence interval (CI)] with/without ketoconazole were 111% (98.4, 127) and 120% (105, 136), respectively, and were 91.3% (80.3, 104) and 104% (91.4, 118), respectively, with/without fluconazole. LasofoxifeneCmaxand AUC ratios (90% CI) with/without paroxetine were 118% (95.4, 146) and 135% (120, 152), respectively.ConclusionsCoadministration of potent inhibitors of CYP3A4/5 and CYP2D6, but not CYP2C9, resulted in a moderate increase in lasofoxifene exposure. No dosage adjustment should be required when lasofoxifene is coadministered with ketoconazole, fluconazole, paroxetine or other agents that inhibit these CYP enzymes.
Characterizing a tropical deforestation wave: a dynamic spatial analysis of a deforestation hotspot in the Colombian Amazon
Authors: ETTER ANDRES , MCALPINE CLIVE , PHINN STUART , PULLAR DAVID , POSSINGHAM HUGH 
Published: July 2006

AbstractTropical deforestation is the major contemporary threat to global biodiversity, because a diminishing extent of tropical forests supports the majority of the Earth's biodiversity. Forest clearing is often spatially concentrated in regions where human land use pressures, either planned or unplanned, increase the likelihood of deforestation. However, it is not a random process, but often moves in waves originating from settled areas. We investigate the spatial dynamics of land cover change in a tropical deforestation hotspot in the Colombian Amazon. We apply a forest cover zoning approach which permitted: calculation of colonization speed; comparative spatial analysis of patterns of deforestation and regeneration; analysis of spatial patterns of mature and recently regenerated forests; and the identification of local‐level hotspots experiencing the fastest deforestation or regeneration. The colonization frontline moved at an average of 0.84 km yr−1 from 1989 to 2002, resulting in the clearing of 3400 ha yr−1 of forests beyond the 90% forest cover line. The dynamics of forest clearing varied across the colonization front according to the amount of forest in the landscape, but was spatially concentrated in well‐defined ‘local hotspots’ of deforestation and forest regeneration. Behind the deforestation front, the transformed landscape mosaic is composed of cropping and grazing lands interspersed with mature forest fragments and patches of recently regenerated forests. We discuss the implications of the patterns of forest loss and fragmentation for biodiversity conservation within a framework of dynamic conservation planning.
Histological evaluation of the osteoinduction capability of human dentine
Authors: Machado M. E. L. , Souza A. S. , Araújo V. C. 
Published: July 2006

AbstractAim  To assess whether human dentine has the potential to promote the development of calcified tissues when implanted in the muscle tissue of mice.Methodology  Root canals in extracted human teeth were instrumented to produce dentine fragments. The dentine fragments produced were divided into two. In group 1, fragments were demineralized and sterilized. In group 2, the fragments were not submitted to any additional treatment. The dentine fragments were then implanted in the muscle of mice. In group 3, the muscles were implanted with rehydrated lyophilized human bone powder. Animals were killed following test periods of 7, 15, 30, 60, 120 and 180 days, the fragments were removed together with adjacent muscle and examined under light microscopy to assess calcification.Results  Areas of calcification were observed in groups 1 and 3 after a period of 180 days. In group 2, the surrounding tissues displayed only chronic inflammatory infiltration.Conclusions  On the basis of the experimental model adopted in this study, fibroblast‐rich connective tissue formed in groups 1 and 3, which could reflect an osteoinductive process. Further studies are suggested to identify which dentinal factors are capable of inducing the formation of a calcified matrix.
Geographic and temporal genetic patterns ofAedes aegyptipopulations in Rio de Janeiro, Brazil
Authors: Da Costa‐Ribeiro Magda C. V. , Lourenço‐de‐Oliveira Ricardo , Failloux Anna‐Bella 
Published: July 2006

SummaryRio de Janeiro is considered as the most important entry point for dengue viruses in Brazil. Using isoenzyme markers, we investigated the genetic structure of the mosquito vectorAedes aegyptisampled at three‐month intervals in 14 districts in Rio de Janeiro from December 2002 to December 2003. We detected high levels of genetic differentiation (i.e. highFSTvalues and significantPvalues), which tended to persist throughout the year. The species does not take advantage of routes and railways to disperse. Genetic structuring was higher in the rainy season, suggesting low dispersion ofAe. aegyptiat this time of year when all dengue epidemics have been reported in the city.
The fate of alien conifers in long‐term plantings in the USA
Authors: Mortenson Susan G. , Mack Richard N. 
Published: July 2006

ABSTRACTFor more than 100 years, non‐native conifers have been introduced into habitats in the USA that already support native conifers. These introductions have yielded few naturalizations and even less evidence of invasions. We investigated the specific fates of nine non‐native conifers in an array of introduction sites across the USA (Priest River, Idaho, Wind River, Washington, Cedar Creek, Minnesota, and Nantucket Is. and Martha's Vineyard, Massachusetts) through tree‐ring analyses, comparisons of growth with adjacent native conifer populations, and surveys for regeneration and spread. Most of the original non‐native tree plantings have died (e.g.Abies veitchii,Pinus densiflora, andPinus halepensisat Wind River, WA); a few have survived but display low vigour and are not regenerating (e.g.Larix decidua,Pinus mugo, andPicea abiesstands at Priest River, ID).Pinus sylvestrisrecruitment is apparent at all sites examined.Pinus thunbergiiappears to be invasive on Nantucket Is., although the nativeBursaphelenchus xylophilus(pinewood nematode) causes high mortality in mature trees. Non‐nativePinusspp. at the Eddy Arboretum, California and Pack Forest, Washington also experienced high mortality. Dendroclimatic analyses revealed no difference in the effect of climate on the annual growth of native and non‐native conifers. Plantations of introduced conifers in the south‐eastern USA have dieden masse(e.g. Harrison Experimental Forest, Mississippi, Olustee Arboretum, Florida). Such widespread extirpations are in sharp contrast to the fate of native conifers in adjacent stands as well as the multiple cases of large‐scale conifer invasions in the Southern Hemisphere. Given the diversity of alien plant species that have invaded the USA, the circumstances surrounding the lack of persistence of introduced conifers becomes an important line of inquiry for understanding the factors and circumstances that facilitate or thwart biological invasions.
Energy For Sustainable Agricultural Development In Zimbabwe
Authors: WEINER DANIEL , MUNSLOW BARRY , MOYO SAM 
Published: July 2006

ABSTRACTZimbabwe's 1992 food crisis revealed both spatial and social contradictions associated with post‐independence agricultural growth. Zimbabwe's pattern of agricultural restructuring demonstrates the need for agrarian reform programs that are more socially and environmentally sustainable. This paper examines one aspect of agricultural sustainability—the use of energy. Post‐independence patterns of agricultural energy consumption are analyzed and traced historically, and the social relations of agricultural energy utilization are investigated. The energetic efficiencies of the primary farming systems are calculated as are the macro‐flows of energy to agriculture generally. The data and historical analysis point to the need for a restructuring of agriculture that involves greater reliance on local renewable energy in all farming systems, and the continued resettlement of black smallholders onto former white‐settler estates.
Migration Regions and Interstate Labor Flows by Occupation in the United States
Authors: ELLIS MARK , BARFF RICHARD , RENARD BEVERLY 
Published: July 2006

ABSTRACTThis paper investigates the migration patterns of occupational groups. The results confirm previous analyses of the differences in movement behavior between occupations but, in addition, show that this variation is a function of the industrial sector of employment. The chief aim of the paper, however, is to uncover the geography of labor flows for different occupational groups using a principal components analysis of interstate flow matrices. The resulting migration regions are homogeneous with respect to the movement behavior of particular classes or labor in each state. Results indicate that migration regions vary by occupation and industry and we argue that these differences reflect job information flows and regional employment structure for various classes of labor. The concluding remarks offer a number of additional avenues for research on occupational migration, and regions in general.
Stochastic analysis of crude oil procurement and processing under uncertain demand for bunker fuel oil
Authors: Zimberg Bernardo , Testuri Carlos E. 
Published: July 2006

AbstractBunker fuel oil (ifo), one of the products of petroleum refining, has a strong impact in the production process because it drives the availability of heavy residues that depend on the crude quality. A simplified stochastic model for the Administración Nacional de Combustibles Alcohol y Portland refinery, based on the uncertainty of the demand for ifo, is proposed for comparison with the current approach of deterministic demand. In this model, the benefits of the production process are maximized, taking decisions on the more suitable raw material, intermediate products and final blends in order to fulfill quality and demand requirements of final products. A specific case is analyzed where the maximum benefit is achieved when the most expensive crude quality is purchased, due to a lack of incentive to produce extra amounts of heavy fuel oil that must be exported at a non‐attractive price. Results are compared with the solution of a deterministic model with mean demand. In addition, the stochastic model solution depicts how the refinery should operate for each scenario of ifo demand.