bluuebunny/crossref_metadata_2025_split huggingface dataset:
The effect of fetoscopic laser therapy on fetal cardiac size in twin–twin transfusion syndrome
Authors: Sueters M. , Middeldorp J. M. , Vandenbussche F. P. H. A. , Teunissen K. A. , Lopriore E. , Kanhai H. H. H. , Le Cessie S. , Oepkes D. 
Published: February 2008

AbstractObjectivesTo evaluate the influence of fetoscopic laser therapy on fetal cardiac size in monochorionic twins complicated by twin–twin transfusion syndrome (TTTS).MethodsIn a longitudinal, prospective study, we assessed fetal cardiac size sonographically in monochorionic diamniotic twins with TTTS treated by laser therapy and in monochorionic twins without TTTS. The fetal cardiothoracic ratio (cardiac circumference divided by thoracic circumference) of TTTS twins was determined within 24 h before, 12–24 h after and 1 week after laser treatment, and from then on every 2–4 weeks until birth. TTTS twins were classified into Quintero Stages 1–2 (n = 18) and Stages 3–4 (n = 16), and measurements were compared with biweekly measurements of non‐TTTS monochorionic twins matched for gestational age (n = 38). Cardiomegaly was defined as a cardiothoracic ratio above the 97.5th percentile.ResultsBefore laser treatment, cardiomegaly was observed in 44% (8/18) and 50% (8/16) of recipients in Quintero Stages 1–2 and Stages 3–4, respectively. Cardiomegaly occurred in none of the donors before treatment. After laser treatment, cardiomegaly was observed in 76% (13/17) and 50% (7/14) of recipients in Stages 1–2 and Stages 3–4, respectively, and in 17% (3/18) and 13% (2/15) of donors in Stages 1–2 and Stages 3–4, respectively. Cardiomegaly was present in 18% (7/38) and 8% (2/25) of non‐TTTS monochorionic twins and singletons. After laser therapy, the cardiothoracic ratio of recipients in Stages 1–2 and Stages 3–4 was not significantly changed (P = 0.34 and P = 0.67, respectively). The cardiothoracic ratio of donors in Stages 1–2 and Stages 3–4 was increased compared with that before laser therapy (P = 0.0002 and P = 0.005, respectively). Cardiothoracic ratios of non‐TTTS monochorionic twins were not significantly different from our reference range in singletons throughout gestation, and were smaller than those in both recipients and donors after laser therapy.ConclusionsTTTS recipients show cardiomegaly before as well as after fetoscopic laser therapy for TTTS. Donors develop cardiomegaly only after laser treatment. Our findings emphasize the significant effect of TTTS and fetoscopic laser therapy on the fetal heart of both recipient and donor twins. Copyright © 2008 ISUOG. Published by John Wiley & Sons, Ltd.
Effects of carrot and tomato juice consumption on faecal markers relevant to colon carcinogenesis in humans
Authors: Schnäbele Kerstin , Briviba Karlis , Bub Achim , Roser Silvia , Pool-Zobel Beatrice L. , Rechkemmer Gerhard 
Published: February 2008

High intakes of carotenoid-rich fruits and vegetables are associated with a reduced risk of various cancers including colon cancer. A human intervention study with carrot and tomato juice should show whether a diet rich in carotenoids, especially high in β-carotene and lycopene, can modify luminal processes relevant to colon carcinogenesis. In a randomised cross-over trial, twenty-two healthy young men on a low-carotenoid diet consumed 330 ml tomato or carrot juice per d for 2 weeks. Intervention periods were preceded by 2-week depletion phases. At the end of each study period, faeces of twelve volunteers were collected for chemical analyses and use in cell-culture systems. Consumption of carrot juice led to a marked increase of β-carotene and α-carotene in faeces and faecal water, as did lycopene after consumption of tomato juice. In the succeeding depletion phases, carotenoid contents in faeces and faecal water returned to their initial values. Faecal water showed high dose-dependent cytotoxic and anti-proliferative effects on colon adenocarcinoma cells (HT29). These effects were not markedly changed by carrot and tomato juice consumption. Neither bile acid concentrations nor activities of the bacterial enzymes β-glucosidase and β-glucuronidase in faecal water changed after carrot and tomato juice consumption. Faecal water pH decreased only after carrot juice consumption. SCFA were probably not responsible for this effect, as SCFA concentrations and profiles did not change significantly. In summary, in the present study, 2-week interventions with carotenoid-rich juices led only to minor changes in investigated luminal biomarkers relevant to colon carcinogenesis.
Internal structure of the Sierra Nevada batholith based on specific gravity and gravity measurements
Authors: Oliver H. W. , Moore J. G. , Sikora R. F. 
Published: February 2008

About 6,000 specific‐gravity (SG) measurements of samples collected from nearly 200 granitic plutons comprising the central Sierra Nevada batholith yield a SG contour map across the batholith from 36.25° to 38° north latitude. With notable exceptions, SG decreases from values generally greater than 2.7 in the west to less than 2.6 over a few small areas of high‐silica, high‐potassium granites near the east edge. A good correlation between measured SG and analyzed weight percent SiO2 enables estimation of average silica variations across the batholith. The average SG is 2.69 corresponding to an average of 68 wt. % SiO2 for the 18,000 km² central part of the batholith.A 1‐km gridded version of the SG measurements has been used to generate a series of synthetic gravity maps, assuming that the SG of rocks at the surface extends unchanged to various depths. The synthetic map computed for a depth of 10 km shows the best correspondence with the isostatic residual gravity map indicating that variations in the observed gravity residuals are largely caused by SG variations of the plutonic rocks exposed at the surface that apparently extend downward to an average depth of about 10 km.Although the 10‐km synthetic gravity map gives the best overall fit to the observed gravity data, comparison of individual anomalies indicates that the bottoms of the plutons as defined by SG variations at the surface are generally shallower along the west edge of the Sierra Nevada (7±2 km) and deeper in the younger and more felsic eastern part (12±3 km). These depths do not necessarily represent a distinct base of the Sierra Nevada batholith. They may indicate the depth below which density homogenization occurs, either by igneous, or possibly, structural processes.
Large massive sulfide deposits in a newly discovered active hydrothermal system, The High‐Rise Field, Endeavour Segment, Juan De Fuca Ridge
Authors: Robigou Véronique , Delaney John R. , Stakes Debra S. 
Published: February 2008

Submersible observations and side‐scan sonar imagery delineate ten large venting sulfide‐sulfate‐silica structures located on an uplifted block of the axial valley floor on the central portion of the Endeavour Segment, Juan de Fuca Ridge. This newly discovered vent field lies 1.8 km north of the main Endeavour vent field. The axial valley, a horst, and faults controlling sulfide deposition trend parallel to the ridge axis. The horst rises 10 to 15 m above the valley floor and offsets a lava lake which extended 500 m in width across the valley. The largest sulfide structures are perched along the major horst‐bounding faults. One structure is the tallest single edifice (45 m) reported in the Pacific Ocean. Smaller, less‐active and inactive sulfide edifices are associated with faulted remnants of the lava lake surface, fissured pressure ridges, and at the edge of collapse pits.Based on the relationship between faults and sulfide structures, the morphology of sulfide edifices, and their venting characteristics, we infer that sulfide structures grow vertically by chimney accumulation and laterally by flange development. Late stage deposition of amorphous silica toughens the large deposits and may be responsible for the unusual size and aspect ratio of Endeavour edifices.
Intraplate earthquakes in the southwest Pacific Ocean Basin and the seismotectonics of the southern Tasman Sea
Authors: Valenzuela Raúl W. , Wysession Michael E. 
Published: February 2008

An examination of 311 intraplate earthquakes in the Australian plate portion of the Pacific Ocean basin reported from 1918 to 1990 reveals that only 113 events are reliably intraplate, with most of the rest relocating to active trenches and transforms. The non‐random distribution of the reliably intraplate events gives insight into the tectonic stresses present. The central Tasman Sea is mostly aseismic except for a swarm of activity at the predicted site of the Tasmantid hot spot. To the north, the broad regions of the Coral Sea, South Fiji Basin and Lord Howe Rise show very little intraplate seismicity, yet the narrow Norfolk Ridge and Three Kings Rise, caught between the double convergence of the New Hebrides and Tonga subduction zones, support many more earthquakes.High levels of intraplate seismicity in the southern Tasman Sea adjacent to the Macquarie Ridge Complex (MRC) indicate that this region may be undergoing internal deformation due to the unusual nature of the Australia‐Pacific plate boundary. Additional support exists in the form of intraplate focal mechanisms similar to those at the plate boundary and a set of parallel gravity rolls which are observed in recent geoid maps. Some aftershocks of the Mw = 8.2 Macquarie Ridge earthquake of 1989 occurred in a fracture zone west of the Macquarie Ridge Complex [Das, 1992], but we have found several earthquakes from as early as 1924 which relocate to this feature, suggesting that its reactivation may be more significant than previously thought. This reactivation of a fossil fracture zone may be the result of the increasing amount of oblique convergence between the Australia and Pacific plates at the Macquarie Ridge Complex, formerly a spreading center, and the stresses associated with subducting recently formed Australian ocean crust beneath the older Pacific plate.
Morphometric evolution of composite volcanoes
Authors: Wood Charles A. 
Published: February 2008

Statistical relations have been determined between geometry, volume, slope, and age for 26 circum‐Pacific composite (strato) volcanoes. General trends in eruption characteristics, repose periods, flow lengths, and petrology are also documented. Few examples of the earliest stages of composite volcano activity are known, perhaps because these small volcanoes are indistinguishable from cinder cones. If cinder cones evolve into composite volcanoes a fundamental change in morphometry, eruption style, and petrology occurs at a basal diameter of 2 km.Composite volcanoes (stratovolcanoes), composed of layered deposits of pyroclastics and lavas, are the characteristic volcanic landform at sub‐ducting plate margins, and are the most abundant type of large volcano on the Earth's surface. Composite volcano morphology results from repeated eruptions of pyroclastics and relatively short lava flows from a central vent. By comparison, pyroclastics are insignificant and lava flows tend to be much longer (10‐100 km) for shield volcanoes. Most composite cones are formed of andesites or basaltic andesites, but some are composed of basalts (Fuji, Fuego, Izalco); thus petrology may be less important in determining the morphology of composite cones than eruption style, as is true for shield volcanoes (Wood, 1977a). In this study, observations of eruption characteristics and chemical/petrological trends for a number of composite cones were synthesized with newly determined measurements of cone morphology to document statistically the evolution of composite volcanoes and to examine their relation to cinder cones. Additionally, such quantitative descriptions of terrestrial volcanoes provide basic data for comparisons with volcanic structures on Mars and the Moon.
A rapid method for magnetic granulometry with applications to environmental studies
Authors: Banerjee Subir K. , King John , Marvin James 
Published: February 2008

We have developed a rapid method of characterizing the fine‐scale variation (sub‐micron to hundreds of microns, µm) in the grain size of magnetite in long sediment cores. This method is a new rock magnetic tool and can be readily applied to the following disciplines: (1) environmental studies; (2) hydrology; (3) petrology; and (4) geomagnetism.The method consists of a comparative plot of the depth variation of two magnetic parameters. The first parameter, low field (less than 0.1 millitesla, mT, or 1 Oe) susceptibility in a steady field is plotted on the abscissa. The second parameter, anhysteretic remanent magnetization (ARM) imparted by a smoothly decreasing AF of peak value 100 mT (1,000 Oe) in the presence of a weak steady field (0.01‐0.1 mT, or 0.1‐1 Oe) is plotted on the ordinate. For a sediment column in which the magnetic mineral is magnetite, a plot of the two magnetic parameters shows transitions in the average magnetic grain size with depth as clearly discernible changes in the slope of a regression line fit to the individual points (χ, ARM).
Source pulse enhancement by deconvolution of an empirical Green's function
Authors: Mueller Charles S. 
Published: February 2008

Observations of the earthquake source‐time function are enhanced if path, recording‐site, and instrument complexities can be removed from seismograms. Assuming that a small earthquake has a simple source, its seismogram can be treated as an empirical Green's function and deconvolved from the seismogram of a larger and/or more complex earthquake by spectral division. When the deconvolution is well posed, the quotient spectrum represents the apparent source‐time function of the larger event. This study shows that with high‐quality locally recorded earthquake data it is feasible to Fourier transform the quotient and obtain a useful result in the time domain. In practice, the deconvolution can be stabilized by one of several simple techniques.In this paper, the method is implemented and tested on high‐quality digital recordings of aftershocks of the Jan. 9, 1982 Miramichi (New Brunswick) earthquake. In particular, seismograms from a Jan. 17 aftershock (017 13:33 GMT, local mag.=3.5) exhibit path or site effects which complicate the determination of source parameters. After deconvolution, the apparent far‐field source of this event is a simple pulse in displacement with duration ≈ 0.07 second for both P and S.
Magnetotelluric observations along the lithoprobe southeastern Canadian Cordilleran Transect
Authors: Jones Alan G. , Kurtz Ron D. , Oldenburg Doug W. , Boerner David E. , Ellis Rob 
Published: February 2008

As part of the LITHOPROBE Southern Cordilleran Transect investigations, twenty‐seven wideband magnetotelluric (MT) responses were obtained along 150 km of the reflection seismic lines. The MT profile begins to the east on the Rocky Mountain Trench above autochthonous North American basement, traverses across the Purcell anticlinorium, the Kootenay Arc, the Nelson batholith, and ends on the east side of the Valhalla gneiss complex.Sites near Kootenay Lake respond to a major near‐surface conductivity anomaly that is probably due to either graphitic schists or to an extension of the silver‐bearing mineralization found further north. The short period (<1 s) data from above the Nelson batholith indicate its thickness extent, whereas the long period (>1 s) data are highly complex and exhibit 3D regional features. Inversions of the data from the two sites on the Valhalla complex yield 1D models with interfaces in electrical conductivity at depths that agree with an increase in the number of reflectors at ≈9 km, “the base of layered reflections” at ≈22 km, and the Mono at ≈35 km.Of major significance to our understanding of the current composition and state of the lower continental crust is that although for the Valhalla complex there are few reflections below ≈22 km the MT responses indicate that the zone is conducting. This is the only location known to the authors where the lower crust is seismically transparent but electrically conductive.
Sensitivity of tropospheric hydrogen peroxide to global chemical and climate change
Authors: Thompson Anne M. , Owens Melody A. , Stewart Richard W. 
Published: February 2008

The sensitivities of tropospheric HO2 and hydrogen peroxide (H2O2) levels to increases in CH4, CO and NO emissions and to changes in stratospheric O3 and tropospheric O3 and H2O have been evaluated with a one‐dimensional photochemical model. Specific scenarios of CH4‐CO‐NOx emissions and global climate changes are used to predict HO2 and H2O2 changes between 1980 and 2030. Calculations are made for urban and nonurban continental conditions and for low latitudes. Generally, CO and CH4 emissions will enhance H2O2 (as OH is converted to HO2); NO emissions will suppress H2O2 except in very low NOx regions. A global warming (with increased H2O vapor) or stratospheric O3 depletion will add to H2O2. Hydrogen peroxide increases from 1980 to 2030 could be 100% or more in the urban boundary layer.Increases in CH4, CO and O3 that have occurred in the industrial era (since 1800) have probably produced temporal increases in background HO2 and H2O2. It might be possible to use H2O2 in ice cores to track these changes. Where formation of sulfuric acid in cloudwater and precipitation is oxidant limited, H2O2 and HO2 increases could be contributing to increases in acid precipitation.
Attenuation in western Nevada: Preliminary results from earthquake and explosion sources
Authors: Hough S. E. , Anderson J. G. , Patton H. J. 
Published: February 2008

We present preliminary results from a study of the attenuation of regional seismic waves at frequencies between 1 and 15 Hz and distances up to 250 km in Western Nevada. Following the methods of Anderson and Hough (1984) and Hough et al. (1988), we parameterize the asymptote of the high frequency acceleration spectrum by a two‐parameter model. We relate the model parameters to a two‐layer model for Qi and Qd, the frequency‐independent and the frequency dependent components of the quality factor. We comparing our results to previously published Q studies in the Basin and Range and find that our estimate of total Q, Qt, in the shallow crust is consistent with shear wave Q at close distances as determined by Chavez and Priestley (1985). For depths greater than 5 km, we obtain a Qt which is consistent with previous estimates of coda Q (Singh and Herrmann, 1983) and LgQ (Chavez and Priestley, 1986), suggesting that both coda Q and LgQ are insensitive to near‐surface contributions to attenuation.In addition to our attenuation results, we compare the high frequency content of explosions with that of earthquakes. Our results from S waves are similar to results for Pg waves by Chael et al. (1987), and Chael (1988), who find that the Pg wave spectra from explosions are depleted in high frequency energy with respect to earthquake spectra. Taylor et al. (1988) look at spectral energy at 1–2 Hz compared to energy at 6–8 Hz for earthquakes and explosions and find, especially for Lg waves, relative depletion of the higher frequencies for explosion sources. This result is also consistent with the results from this study.
Central and South America GPS geodesy ‐ CASA Uno
Authors: Kellogg James N. , Dixon Timothy H. 
Published: February 2008

In January 1988, scientists from over 25 organizations in 13 countries and territories cooperated in the largest Global Positioning System (GPS) campaign in the world to date (Table 1). 43 GPS receivers collected approximately 590 station‐days of data in American Samoa, Australia, Canada, Colombia, Costa Rica, Ecuador, New Zealand, Norway, Panama, Sweden, United States, West Germany, and Venezuela. The experiment was entitled CASA UNO, an acronym for Central and South America – and uno is the Spanish word for one, designating first epoch measurements. The CASA UNO experiment was the first civilian effort implementing a global GPS satellite tracking network.Scientific goals of the project include measurement of strain in the northern Andes, measurement of subduction rates for the Cocos and Nazca plates beneath Central and South America, and measurement of relative motion between the Caribbean plate and South America. A second set of measurements are planned in 1991 (CASA DOS), and should provide preliminary estimates of crustal deformation and plate motion rates in the region. The CASA series of experiments are intended to be carried out over at least one decade.
Plasma composition measurements of the Martian magnetosphere morphology
Authors: Lundin R. , Zakharov A. , Pellinen R. , Borg H. , Hultqvist B. , Pissarenko N. , Dubinin E. M. , Barabasj S. W. , Liede I. , Koskinen H. 
Published: February 2008

Plasma composition measurements from the Phobos‐2 spacecraft have revealed new data on the dynamics and composition of plasmas in the Martian magnetosphere—a magnetosphere being significantly wider and more dynamic than was anticipated before. The tail width is some 6–9 Mars radii at antisolar distances greater than ten Martian radii and it contains some features that are similar to those observed in the Geotail. The strong dominance of plasma of Martian origin implies a modest access of solar wind particles into the central tail. Heavy ions like O+ are in fact up to ten times more abundant then H+. Some plasma properties, such as the characteristics of the ionospheric ion outflow, the presence of a distinct plasma sheet and the overall width of the tail are arguments for a weak intrinsic magnetic field on Mars. However, yet other plasma characteristics, such as strong ion pick‐up processes, indicates a Venus‐like interaction. Thus, our present view based on primarily plasma measurements is that Mars constitutes a hybrid obstacle to the solar wind.The observation of two distinctly different plasma boundaries suggests that the magnetosphere of Mars is contained whithin an exterior / composition boundary—termed the Mass‐Loading Boundary (MLB), and an interior boundary—a “magnetopause”. MLB marks the boundary for a cometary‐like interaction and the “magnetopause” the limit of solar wind plasma entry—possibly also constituting the boundary for an intrinsic magnetic field.
δs at high pressure and dlnVs/dlnVp in the lower mantle
Authors: Agnon A. , Bukowinski M. S. T. 
Published: February 2008

δs, a measure of the sensitivity of the adiabatic bulk‐modulus to isobaric density changes, controls lateral variations of P‐wave velocities. To estimate the effect of pressure on δs, we have performed lattice dynamic calculations of the cubic alkaline earth oxides. We used a many‐body parametric Hamiltonian that reproduces the available laboratory data on thermoelastic properties. The calculations were carried out for P‐T conditions that correspond to those of the lower mantle. We find that δs decreases from 4±1 at standard conditions to ≤ 2 at lower mantle conditions. The latter value is consistent with D.L. Anderson's estimates based on geophysical data.With δs ≤ 2, and a corresponding parameter for shear modulus not decreasing with compression, no partial melting is required to account for the observation that ΔlnVs/ΔlnVp ≥ 2 in the lower mantle. Although more data and calculations on additional minerals are needed to draw any firm conclusions, our results indicate that the relatively small lateral variations of lnVp, when compared to lnVs, are due entirely to compressional effects.