bluuebunny/crossref_metadata_2025_split huggingface dataset:
Petrological and geochemical constraints on the composition of the lithospheric mantle beneath the Syrian rift, northern part of the Arabian plate
Authors: Ismail M. , Delpech G. , Cottin J.-Y. , Grégoire M. , Moine B. N. , Bilal A. 
Published: January 2008

Abstract

A suite of mantle xenoliths from the Neogene–Quaternary volcanic province of Jabel El Arab (Syria) is dominated by spinel±amphibole harzburgites, with rare lherzolites and wehrlites that were equilibrated at temperatures of 900–1100 °C. The major elements of pristine minerals and trace element compositions of clinopyroxene and amphibole indicate that the lithospheric mantle experienced various degrees of melt extraction (olivine Mg-number=89.4–91.8, spinel Cr-number=10.4–46.4), followed by a multistage metasomatic history. The primary clinopyroxene has variable and high Mg-number (89.1–93.6) and highly variable major element concentrations (Al
2
O
3
2.7–7.6 wt%, Na
2
O 0.5–2.5 wt% and Cr
2
O
3
0.4–2.5 wt%). Three groups of harzburgites were identified on the basis of petrographical, mineralogical and geochemical data. Group I harzburgites have compositions indicating a residual origin after polybaric partial melting with
F
<20%, which started in the garnet stability field and continued in the spinel stability field. Group II harzburgites are interpreted as a result of a percolation mechanism involving the infiltration of large volumes of undifferentiated basaltic melts through the residual lithosphere. Finally, the mineral major element compositions and the selectively enriched trace element contents of clinopyroxenes in group III harzburgites (high (La/Sm)
N
and Th, U, Sr and low high field strength element contents) are attributed to a percolation mechanism involving small volume melt fractions. Such small melt fractions correspond to CO
2
-bearing alkaline silicate magmas that have evolved to CO
2
-rich melts during repeated percolation-reaction within the Syrian lithospheric mantle. Shortly before eruption, some xenoliths were infiltrated by small silicate melt fractions, which produced discrete reaction zones composed of cpx±ol±sp±glass surrounding reacting primary spinels. The glass in the melt pockets has a trachytic to trachy-andesitic composition and its composition suggests that glass is derived from melting of pre-existing amphibole in the lithospheric mantle, triggered by infiltration of a Na-rich metasomatic agent.
The role of HIMU metasomatic components in the North African lithospheric mantle: petrological evidence from the Gharyan lherzolite xenoliths, NW Libya
Authors: Beccaluva L. , Bianchini G. , Ellam R. M. , Marzola M. , Oun K. M. , Siena F. , Stuart F. M. 
Published: January 2008

Abstract

The Neogene–Quaternary alkali-basalt–hawaiite lavas of the Gharyan volcanic field (NW Libya) contain mantle xenoliths. These mostly consist of protogranular spinel lherzolites with superimposed metasomatic textures represented by reaction patches where primary orthopyroxene (opx), clinopyroxene (cpx) and spinel (sp) are the main reacting phases. The secondary parageneses include clinopyroxene (cpx2), olivine (ol2) and feldspar (feld) as reaction rims around opx, spongy-textured clinopyroxene with recrystallized portions (cpx2±feldspar), and brown spinel destabilized in a higher Cr/(Cr+Al) black vermicular aggregate (sp2) generally associated with feldspar microlites. Cpx2 are typically depleted in Na
2
O and Al
2
O
3
relative to cpx; feldspar includes both alkali-feldspar (Or 17–51) and plagioclase (An 23–64). Bulk rocks have flat heavy rare earth element (HREE) patterns (1.2–2.3 times chondrite) and are variably enriched in light REE (LREE; La
N
/Yb
N
up to 6.6). The constituent clinopyroxenes are characterized by flat HREE distributions (8–14.5 times chondrite) and variable LREE enrichment with La
N
/Yb
N
up to seven, which generally conform to the bulk-rock chemistry. Samples relatively unaffected by metasomatism have clinopyroxene Sr–Nd isotopic composition (
87
Sr/
86
Sr down to 0.7023,
143
Nd/
144
Nd up to 0.5139) that approaches the depleted mantle (DM), suggesting that the lithospheric mantle beneath the area underwent a long-term depletion probably by pre-Palaeozoic extraction of basic melts. The remaining samples approach
87
Sr/
86
Sr
c
. 0.7030,
143
Nd/
144
Nd
c
. 0.5130, with
206
Pb/
204
Pb up to 19.66. These data imply that the causative agents of metasomatism were Na-alkali silicate melts with a clear HIMU affinity, in accordance with the isotopic signature of the host lavas (
87
Sr/
86
Sr=0.7032,
143
Nd/
144
Nd=0.5130,
206
Pb/
204
Pb=19.60). This prevalent HIMU geochemical signature is comparable with that recorded in Cenozoic alkaline basic lavas and associated mantle xenoliths from other occurrences of the northern–central African lithosphere, suggesting a common regional sub-lithospheric component. The relatively low
3
He/
4
He of the Gharyan xenoliths (5.3–6.5
R
a
) indicates that this component originates within the upper mantle and is unrelated to the deep-seated mantle plume source of the Ethiopian–Yemen plateau basalts. Therefore, the Cenozoic volcanic districts of the Saharan belt could be related to smaller-scale shallow mantle upwellings (also referred to as ‘hot fingers’) triggered by intraplate reactivation of regional tectonic lineaments within the Pan-African cratonic basement, as a foreland reaction of the African–Europe collisional system.
The Jurassic Ligurian Tethys, a fossil ultraslow‐spreading ocean: the mantle perspective
Authors: Piccardo G. B. 
Published: January 2008

Abstract

Alpine–Apennine ophiolites derive from the Jurassic Ligurian Tethys oceanic basin formed by lithosphere extension and failure in the pre-Triassic Europe–Adria system. The basin was floored by mantle peridotites and was characterized by along-axis alternation of avolcanic and volcanic segments. Lithosphere extension and thinning caused asthenosphere adiabatic upwelling and decompressional melting. Mid-ocean ridge basalt (MORB)-type melts diffusely percolated through and reacted with the overlying lithospheric peridotites, which were strongly modified, both depleted (harzburgites and dunites) and enriched (plagioclase peridotites), by melt–peridotite interaction and melt refertilization. The stratigraphic–structural features (mantle at the sea floor and alternation of avolcanic and volcanic segments) coupled with petrological features (presence of alkaline melts and strongly heterogeneous, melt-modified peridotites) allow us to interpret
the Ligurian Tethys as a Jurassic analogue of modern ultraslow‐spreading oceans
. The Liguria Mode for the inception of an oceanic basin consists of: (1)
the rifting (continental) stage
, dominated by extension of continental lithosphere and tectonic exhumation of lithospheric mantle; (2)
the drifting (transition) stage
, characterized by melt-related processes (i.e. inception of asthenosphere partial melting and MORB melt percolation through the overlying mantle lithosphere); (3)
the spreading (oceanic) stage
, characterized by failure of the continental crust, sea‐floor exposure of mantle peridotites and discontinuous MORB extrusion.
Types of metasomatism in mantle xenoliths enclosed in Neogene-Quaternary alkaline mafic lavas from Catalonia (NE Spain)
Authors: Galán G. , Oliveras V. , Paterson B. A. 
Published: January 2008

Abstract
Mantle xenoliths in within-plate alkaline mafic lavas from NE Spain are mainly anhydrous spinel lherzolites and harzburgites, grading into each other, and subordinate pyroxenites. Peridotites followed an earlier melt depletion caused by mantle decompression and subsequent metasomatism. Two main types of metasomatism are differentiated affecting mainly the harzburgites: a silicate-melt metasomatism of Fe–Ti type and a carbonatite metasomatism. Both types are recognized in the nearby Pyrenean peridotite massifs, but the presence of hydrous minerals is less frequent in the xenoliths. The two metasomatic styles could have been generated by the intrusion of Cretaceous alkaline magmas, if a chromatographic fractionation–reaction process at decreasing melt mass took place. This would account for the evolution of the original alkaline silicate percolating melt towards a carbonatite-rich melt, allowing the coexistence in both space and time of the two metasomatic styles. Metasomatism in lherzolites could be explained in the same way. The pyroxenite xenoliths are interpreted as cumulates from these alkaline basic magmas that crop out in the area as rare camptonite dykes. Interaction with host lavas is minor and could explain the partial melting, enrichment and disequilibrium observed in a deformed composite xenolith and sporadic veins filled with glass.
Plume-related stable isotope compositions and fluid–rock interaction processes in the Basal Complex of La Palma, Canary Islands, Spain
Authors: Demény A. , Casillas R. , Vennemann T. W. , Hegner E. , Nagy G. , Ahijado A. , De La Nuez J. , Sipos P. , Pilet S. , Milton J. 
Published: January 2008

Abstract
Chemical and isotopic compositions of amphiboles, biotites, pyroxenes and feldspars from gabbros and basalts of La Palma, Canary Islands, were studied to determine primary, plume-related compositions and effects of late-stage water–rock interactions. All the studied amphiboles have Sr isotope ratios close to those typical for the mantle, excluding the possibility of significant seawater influence. The pyroxenes and amphiboles also have stable isotope compositions that are typical for mantle-derived phases, whereas biotites and feldspars show signs of interaction with meteoric water. On the basis of the oxygen isotopic compositions, the infiltrating meteoric water derived from precipitation at an approximate elevation of 3500 m above sea level, indicating that La Palma reached this height when the gabbro complexes were formed. The unaltered hydrogen and oxygen isotope compositions of amphiboles show a trend from normal mantle ranges to −90‰ and 5.1‰, respectively; these values are very close to compositions found in other Canary Island complexes by earlier studies, and support the theory that these compositions reflect a plume component originating from depth, rather than local phenomena.
Estimating Nielsen Numbers on Wedge Product Spaces
Authors: Khamsemanan Nirattaya , Kim Seung Won 
Published: January 2008

AbstractLet "Equation missing" be a self-map of a finite polyhedron that is an aspherical wedge product space "Equation missing". In this paper, we estimate the Nielsen number "Equation missing" of "Equation missing". In particular, we study some algebraic properties of the free products and then estimate Nielsen numbers on torus wedge surface with boundary, Klein bottle wedge surface with boundary, and torus wedge torus.
A Parametric Time Domain Method for Spectral Moment Estimation and Clutter Mitigation for Weather Radars
Authors: Nguyen Cuong M. , Moisseev Dmitri N. , Chandrasekar V. 
Published: January 2008

Abstract
A parametric time domain method (PTDM) for clutter mitigation and precipitation spectral moments’ estimation for weather radars is introduced. Use of PTDM allows for the simultaneous estimation of clutter and precipitation echo spectral moments. It is shown that this approach leads to accurate estimates of precipitation spectral moments in the presence of clutter. Based on simulations, the PTDM performance is evaluated and compared against the clutter spectral filtering technique. In this study special attention is paid to the cases of strong clutter contamination. Furthermore, both methods, the PTDM and spectral clutter filter, are illustrated using the Colorado State University–University of Chicago–Illinois State Water Survey (CSU–CHILL) observations.
Simulated Doppler Radar Observations of Inhomogeneous Clouds: Application to the EarthCARE Space Mission
Authors: Schutgens N. A. J. 
Published: January 2008

Abstract
A new simulation technique for spaceborne Doppler radar observations that was developed specifically for inhomogeneous targets is presented. Cloud inhomogeneity affects Doppler observations in two ways. First, line-of-sight velocities within the instantaneous field of view are unequally weighted. As the large forward motion of a spaceborne radar contributes to these line-of-sight velocities this causes biases in observed Doppler speeds. Second, receiver voltages now have time-varying stochastical properties, increasing the inaccuracy of Doppler observations. The new technique predicts larger inaccuracies of observed Doppler speeds than the traditional random signal simulations based on the inverse Fourier transform.
The accuracy of Doppler speed observations by a spaceborne 95-GHz radar [as part of the proposed European Space Agency (ESA)/Japan Aerospace Exploration Agency (JAXA)/National Institute for Information and Communications Technology (NICT) EarthCARE mission] is assessed through simulations for realistic cloud scenes based on observations made by ground-based cloud-profiling radars. Close to lateral cloud boundary biases as large as several meters per second occur. For half of the cloud scenes investigated, the distribution of the in-cloud bias has an rms of 0.5 m s−1, implying that a bias in excess of 0.5 m s−1 will not be uncommon.
An algorithm to correct the bias in observed Doppler observations, based on the observed gradient of reflectivity along track, is suggested and shown to be effective; that is, the aforementioned rms bias reduces to 0.14 m s−1.
Feature Extraction from Whole-Sky Ground-Based Images for Cloud-Type Recognition
Authors: Calbó Josep , Sabburg Jeff 
Published: January 2008

Abstract
Several features that can be extracted from digital images of the sky and that can be useful for cloud-type classification of such images are presented. Some features are statistical measurements of image texture, some are based on the Fourier transform of the image and, finally, others are computed from the image where cloudy pixels are distinguished from clear-sky pixels. The use of the most suitable features in an automatic classification algorithm is also shown and discussed. Both the features and the classifier are developed over images taken by two different camera devices, namely, a total sky imager (TSI) and a whole sky imager (WSC), which are placed in two different areas of the world (Toowoomba, Australia; and Girona, Spain, respectively). The performance of the classifier is assessed by comparing its image classification with an a priori classification carried out by visual inspection of more than 200 images from each camera. The index of agreement is 76% when five different sky conditions are considered: clear, low cumuliform clouds, stratiform clouds (overcast), cirriform clouds, and mottled clouds (altocumulus, cirrocumulus). Discussion on the future directions of this research is also presented, regarding both the use of other features and the use of other classification techniques.
Impact of Resolution and Optimized ECCO Forcing on Simulations of the Tropical Pacific
Authors: Hoteit I. , Cornuelle B. , Thierry V. , Stammer D. 
Published: January 2008

Abstract
The sensitivity of the dynamics of a tropical Pacific Massachusetts Institute of Technology (MIT) general circulation model (MITgcm) to the surface forcing fields and to the horizontal resolution is analyzed. During runs covering the period 1992–2002, two different sets of surface forcing boundary conditions are used, obtained 1) from the National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) reanalysis project and 2) from the Estimating the Circulation and Climate of the Ocean (ECCO) assimilation consortium. The “ECCO forcing” is the “NCEP forcing” adjusted by a state estimation procedure using the MITgcm with a 1° × 1° global grid and the adjoint method assimilating a multivariate global ocean dataset. The skill of the model is evaluated against ocean observations available in situ and from satellites. The model domain is limited to the tropical Pacific, with open boundaries located along 26°S, 26°N, and in the Indonesian throughflow. To account for large-scale changes of the ocean circulation, the model is nested in the global time-varying ocean state provided by the ECCO consortium on a 1° grid. Increasing the spatial resolution to 1/3° and using the ECCO forcing fields significantly improves many aspects of the circulation but produces overly strong currents in the western model domain. Increasing the resolution to 1/6° does not yield further improvements of model results. Using the ECCO heat and freshwater fluxes in place of NCEP products leads to improved time-mean model skill (i.e., reduced biases) over most of the model domain, underlining the important role of adjusted heat and freshwater fluxes for improving model representations of the tropical Pacific. Combinations of ECCO and NCEP wind forcing fields can improve certain aspects of the model solutions, but neither ECCO nor NCEP winds show clear overall superiority.
Photoencapsulation of Bone Morphogenetic Protein-2 and Periosteal Progenitor Cells Improve Tendon Graft Healing in a Bone Tunnel
Authors: Chen Chih-Hwa , Liu Hsia-Wei , Tsai Ching-Lin , Yu Chung-Ming , Lin I-Hsuan , Hsiue Ging-Ho 
Published: January 2008

Background Tissue-engineered solutions for promoting the tendon graft incorporation within the bone tunnel appear to be promising. Hypothesis To determine the feasibility that conjugation of hyaluronic acid-tethered bone morphogenetic protein-2 can be used to stimulate periosteal progenitor cells direct fibrocartilagenous attachment and new bone formation in an extra-articular tendon-bone healing model. Study Design Controlled laboratory study. Methods A total of 42 mature New Zealand White rabbits were used. The long digitorum extensor tendon was transplanted into a bone tunnel of the proximal tibia. The tendon was pulled through a drill hole in the proximal tibia and attached to the medial aspect of the tibia. Photopolymerizable hydrogel based on poly (ethylene glycol) diacrylate with hyaluronic acid-tethered bone morphogenetic protein-2 was injected and photogelated in a bone tunnel. Histological and biomechanical examination of the tendon-bone interface was evaluated at postoperative weeks 3 and 6. Results Histological analysis showed an interface fibrocartilage and new bone formed by photoencapsulation of bone morphogenetic protein-2 and periosteal progenitor cells at 6 weeks. Biomechanical testing revealed higher maximum pullout strength and stiffness in experimental groups with a statistically significant difference at 3 and 6 weeks after tendon transplantation. Conclusion The healing tendon-bone interface undergoes a gradual remodeling process; it appears that photoencapsulation of bone morphogenetic protein-2 and periosteal progenitor cells possesses a powerful inductive ability between the tendon and the bone to incorporate the healing in a rabbit model. Clinical Relevance Novel technologies, such as those described in this study, including photopolymerization and tissue engineering, may provide minimally invasive therapeutic procedures via arthroscopy to enhance biological healing after reconstruction of the anterior cruciate ligament.
An Analysis of Capsular Area in Patients with Anterior, Posterior, and Multidirectional Shoulder Instability
Authors: Dewing Christopher B. , McCormick Frank , Bell S. Josh , Solomon Daniel J. , Stanley Mark , Rooney Timothy B. , Provencher Matthew T. 
Published: January 2008

Background Although increased capsular volume has been implicated in shoulder instability, there is a paucity of clinical evidence to quantify the size of the capsule with specific instability conditions of the shoulder. Hypothesis Shoulder capsular area, as measured by magnetic resonance arthrography, is increased with specific patterns of shoulder instability. Study Design Cross-sectional study; Level of evidence, 4. Methods During an 8-month period, all patients with a diagnosis of anterior (n = 19), posterior (n = 14), or multidirectional (n = 13) instability of the shoulder and who were assessed with a magnetic resonance arthrogram were reviewed. A group of 10 control patients without clinical instability were also identified. The magnetic resonance arthrograms of all groups were randomly mixed, and 5 reviewers recorded measures of capsular length and area and determined labral abnormalities. The magnetic resonance arthrogram measurements were compared between groups, and interobserver agreement was determined. Results The cross-sectional area of the capsule was increased in patients with posterior ( P = .017) or multidirectional instability ( P = .021) versus controls, but not in patients with anterior instability. Additionally, the posteroinferior cross-sectional area was increased in patients with posterior ( P = .001), multidirectional ( P = .003), and anterior ( P = .008) instability. In patients with a posterior labral tear, the mean axial ( P = .043) and mean posteroinferior sagittal cross-sectional area ( P = .011) was increased, but there were no differences in cross-sectional area for those with an anterior labral tear. The overall interobserver reliability was very good (correlation coefficient range, 0.68–0.94). Conclusion Our results reinforce the concept that capsular elongation and laxity, either preexisting or acquired, play a role in certain instability conditions of the shoulder. Additional work is needed to determine how to correlate surgical decision making with the cross-sectional area measurements demonstrated in this study.
Quality of Frozen Turkey Crepes in Relation to Antioxidants Used and Length of Storage at 0°F.1
Authors: Payton Sharon B. , Carlin Agnes Frances 
Published: January 2008

The major objective was to evaluate the quality of precooked frozen turkey crepes stored at 0°F. (−18°C.) up to 6 months. Strips of raw breast or thigh meat, treated with a solution of salt, sugar, and one of the antioxidants (polyphosphates, ascorbic acid, or a combination of the two) were made into rolls and cooked in waterproof casings to 160°F. (71°C.) in 190°F. (88°C.) water. Rolls were sliced and cubed. The cubed turkey meat in cream sauce was enclosed in a crepe. Turkey crepes were packaged four in each aluminum pan (770 g., 1.7 lbs.), and frozen. After storage at 0°F. for 0, 4, or 6 months, samples were heated at 350°F. (177°C.) to 160°F. (71°C.) and scored for quality. The light or the dark turkey meat cubes, the cream sauce, and the crepes (thin pancakes) were evaluated separately.Evaluation by a trained taste panel revealed that the three antioxidant treatments were effective in maintaining turkey flavor and in preventing rancidity. Ascorbic acid alone was slightly less effective than polyphosphates either alone or combined with ascorbic acid. Cream sauces made with flour (1/3) and modified cornstarch (2/3) did not separate after freezing and reheating to 160°F. Cream sauces containing corn oil and crepes containing margarine were not rancid. Thus, the results indicated that the frozen turkey crepes had good eating quality after storage for 6 months at 0°F.