bluuebunny/crossref_metadata_2025_split huggingface dataset:
Early to middle Proterozoic dykes in the Mt. Riiser-Larsen area of the Napier Complex, East Antarctica: tectonic implications as deduced from geochemical studies
Authors: Suzuki Satoko , Ishizuka Hideo , Kagami Hiroo 
Published: November 2008

Abstract

NE–SW- and north–south-striking dykes were emplaced into ultrahigh-temperature (UHT) granulites apparently after UHT metamorphism in the Mt. Riiser-Larsen area of the Archaean Napier Complex, East Antarctica, of which the north–south-striking dykes interrupt the NE–SW-striking ones. The NE–SW-striking dykes are tholeiite basalt (THB) and high-magnesian andesite (HMA) in composition. The THB dykes display relict doleritic textures, whereas the HMA dykes shows blastoporphyritic textures characterized by phenocrysts of clinopyroxene and plagioclase. Both sets of dykes exhibit large ion lithophile element and light rare earth element enrichment and negative anomalies of Nb, Ti and/or P in a spider diagram normalized to primitive mantle, which is reminiscent of modern subduction-related arc volcanism or continental flood volcanism. The isotope ratios of the THB dykes define isochron ages of 2.0–1.9 Ga: 1979±80 Ma in the Rb–Sr system (initial ratio (
I
0
): 0.70239±0.00035) and 2078±104 Ma in the Sm–Nd system (
I
0
: 0.50964±0.00012). Such moderate
87
Sr/
86
Sr and low
143
Nd/
144
Nd initial ratios may represent source materials closely related to the mantle wedge of a subduction zone. The north–south-striking dykes are compositionally divided into two basalt types. One is an alkaline basalt (AL) showing intergranular texture and characterized by high concentrations of incompatible elements, similar to those of ocean island basalt. They yield an isochron age of
c.
1.2 Ga: 1161±238 Ma in the Rb–Sr system (
I
0
: 0.7047±0.0012). The other type (THB-m) is doleritic (ophitic) in texture, and has a tholeiitic affinity with a flat chondrite-normalized REE pattern, which is comparable with that of enriched mid-ocean ridge basalt. A comparison with dykes reported from other areas of the Napier Complex suggests that the north–south-striking dykes occur in restricted areas, whereas the NE–SW-striking dykes are more regional in occurrence. The 2.0–1.9 Ga magmatism of the NE–SW-striking dykes may have been related to the formation of continental crust of the Rayner Complex.
Magmatic evolution and tectonic setting of metabasites from Lützow-Holm Complex, East Antarctica
Authors: Suda Yoshimitsu , Kawano Yoshinobu , Yaxley Greg , Korenaga Hiroshi , Hiroi Yoshikuni 
Published: November 2008

Abstract
Metabasites from the Lützow-Holm Complex, East Antarctica, are the equivalent of metamorphosed ultramafic and mafic rocks with ultrabasic to intermediate compositions, which occur as layers and blocks in the quartzo-feldspathic or metasedimentary gneisses. Field occurrences and whole-rock geochemistry suggest that the ultramafic rocks are all cumulitic protoliths, whereas the mafic rocks are mostly basaltic protoliths including some cumulates. Moreover, in a regional context, the geochemistry of metabasites shifts from island arc to ocean-floor affinities in a southwesterly direction from the Prince Olav Coast to the Lützow-Holm Bay area. Neodymium isotopic data suggest that the metamorphic rocks from the Prince Olav Coast and the northern Lützow-Holm Bay areas were derived from immature continental crust formed by active Mesoproterozoic crustal growth, whereas those from the southern Lützow-Holm Bay area were derived from mature continental crust and oceanic crust of older age. Thus, these results suggest that the Lützow-Holm Complex includes lithological units with various origins and ages that were amalgamated by multiple subduction, and underwent high-grade metamorphism as a result of the final collision of East and West Gondwana during the Pan-African orogeny.
Geodynamic evolution of Mt. Riiser-Larsen, Napier Complex, East Antarctica, with reference to the UHT mineral associations and their reaction relations
Authors: Hokada Tomokazu , Motoyoshi Yoichi , Suzuki Satoko , Ishikawa Masahiro , Ishizuka Hideo 
Published: November 2008

Abstract

Mt. Riiser-Larsen is the largest outcrop in the Archaean–early Proterozoic Napier Complex, East Antarctica. The area is structurally divided into the Main and the Western Blocks by the subvertical Riiser-Larsen Main Shear Zone (RLMSZ) of about 200 m width composed of mylonite and pseudotachylite. Mineral parageneses including sapphirine+quartz and osumilite, diagnostic of ultrahigh-temperature (UHT) metamorphism, are found in Mg-rich aluminous, siliceous and quartzo-feldspathic gneiss layers in both the Main and the Western Blocks of the Mt. Riiser-Larsen area. Some of the sapphirine–quartz associations are accompanied by retrograde reaction textures, which include growth of cordierite and/or garnet between sapphirine and quartz in the Main Block, and of orthopyroxene+sillimanite in the Western Block. These textures indicate the reaction

(1)

sapphirine
+
quartz
(
+
orthopyroxene
)
=
cordierite

and

(2)

sapphirine
+
quartz
(
+
orthopyroxene
)
=
garnet

in the Main Block and

(3)

sapphirine
+
quartz
=
orthopyroxene
+
sillimanite

in the Western Block. Phase equilibria and
P
–
T
pseudosections for sapphirine+quartz-bearing associations suggest that these three reactions took place during a temperature drop from 1100 °C to 1000 °C at pressures of 0.6–0.8 GPa in the Main Block and 0.8–0.9 GPa in the Western Block. The geological structure and distribution of the UHT rocks provide an insight into the vertical extent of the>1000 °C UHT metamorphic zone: a minimum thickness of 4–5 km of the UHT-metamorphosed layers, which become deeper towards the west in the Main Block. The Western Block represents a
c.
0.1–0.3 GPa (
c.
3–10 km) deeper structural level than the Main Block. In addition to the extent of the horizontal distribution of UHT metamorphism in the Napier Complex, our results on the vertical component provide new constraints for modelling the heat source and tectonic process of the unusually high-temperature regional metamorphism in the late Archaean–early Proterozoic. Electron microprobe monazite U–Th–Pb dating for hydrated and mylonitized sapphirine–quartz gneiss gave a wide spectrum of monazite age distribution between 2300 and 800 Ma, suggesting the tectonic uplift and juxtaposition of the two blocks in the Mt. Riiser-Larsen area later than the mid–late Proterozoic.
Crystal size distribution of garnet in quartzo-feldspathic gneisses from the Lützow-Holm Complex at Skallen, East Antarctica
Authors: Goto Saori , Ikeda Takeshi 
Published: November 2008

Abstract
Crystal size distributions (CSDs) of garnet in quartzo-feldspathic gneisses from the Lützow-Holm Complex at Skallen, East Antarctica, indicate that significant annealing with Ostwald ripening did not take place even though the rocks underwent regional granulite-facies metamorphism with a peak phase of ultrahigh-temperature conditions. Absence of fluid as a result of the complete consumption of hydrous minerals during garnet-forming reactions could restrain intergranular diffusion and inhibit Ostwald ripening. Garnet-poor gneisses have experienced a single nucleation and growth event associated with a continuous garnet-forming reaction. In contrast, garnet-rich gneisses from the same outcrop have undergone additional garnet-forming reactions responsible for multiple stages of nucleation and growth.
Fe
2+
–Mg partitioning experiments between orthopyroxene and spinel using ultrahigh-temperature granulite from the Napier Complex, East Antarctica
Authors: Sato Kei , Miyamoto Tomoharu , Kawasaki Toshisuke 
Published: November 2008

Abstract

Temperature dependence of the Fe
2+
–Mg exchange between orthopyroxene (Opx) and spinel (Spl),

1
/
2

Fe
2

Si
2

O
6

+

MgAl
2

O
4

=
1
/
2

Mg
2

Si
2

O
6

+

FeAl
2

O
4

Opx

Spl

Opx

Spl

was experimentally determined at 9–13 kbar and 900–1200 °C using an ultrahigh-temperature (UHT) granulite collected from the Napier Complex in Enderby Land, East Antarctica. The Fe
2+
–Mg distribution coefficient,

K
D

=

X

Fe

Spl

X

Mg

Opx

X

Mg

Spl

X

Fe

Opx

is empirically obtained as

ln

K
D

=
−
1.134
+
[
2341
+
7.5
(
P
−
11
)
]
/
T

where
X
is the cationic mole fraction, and pressure
P
and temperature
T
are in kbar and Kelvin, respectively. The new geothermometer was applied to various natural UHT and associated high-grade metamorphic rocks from East Antarctica and other regions of the world. The results indicate temperatures between 735 and 902 °C at pressures in the range of 5–14 kbar. This geothermometer utilizing spinel does not give peak metamorphic condition, because it is relatively easy for spinel to re-equilibrate during the cooling stage of metamorphism. Hence, we conclude that the geothermometer is suitable for evaluating the closure temperature for the
K
D
between aluminous orthopyroxene and spinel during retrograde metamorphism rather than the thermal peak.
Terrane correlation between Antarctica, Mozambique and Sri Lanka; comparisons of geochronology, lithology, structure and metamorphism and possible implications for the geology of southern Africa and Antarctica
Authors: Grantham G. H. , Macey P. H. , Ingram B. A. , Roberts M. P. , Armstrong R. A. , Hokada T. , Shiraishi K. , Jackson C. , Bisnath A. , Manhica V. 
Published: November 2008

Abstract

Analysis of new lithological, structural, metamorphic and geochronological data from extensive mapping in Mozambique permits recognition of two distinct crustal blocks separated by the Lurio Belt shear zone. Extrapolation of the Mozambique data to adjacent areas in Sri Lanka and Dronning Maud Land, Antarctica permits the recognition of similar crustal blocks and allows the interpretation that the various blocks in Mozambique, Sri Lanka and Antarctica were once part of a mega-nappe, forming part of northern Gondwana, which was thrust-faulted
c.
600 km over southern Gondwana during amalgamation of Gondwana at
c.
590–550 Ma. The data suggest a deeper level of erosion in southern Africa compared with Antarctica. It is possible that this thrust domain extends, through the Zambezi Belt or Valley, as far west as the Damara Orogen in Namibia with the Naukluft nappes in Namibia, the Makuti Group, the Masoso Suite in the Rushinga area and the Urungwe klippen in northern Zimbabwe, fitting the mega-nappe pattern. Erosional products of the mountain belt are now represented by 700–400 Ma age detrital zircons present in the various sandstone formations of the Transantarctic Mountains, their correlatives in Australia, as well as the Urfjell Group (western Dronning Maud Land) and probably the Natal Group in South Africa.
Macroscopic geological structures of the Napier and Rayner Complexes, East Antarctica
Authors: Toyoshima T. , Osanai Y. , Nogi Y. 
Published: November 2008

Abstract

This paper presents a form-line map of the Napier and Rayner Complexes, East Antarctica, constructed from attitude data for foliations shown on published geological maps, and discusses the macroscopic geological structures. The form-line map shows that the two complexes consist of several, structurally distinct, units or blocks bounded by east–west-, NE–SW- and NW–SE-striking faults. The major boundary between the two complexes, as indicated on the published geological maps, is a structural discontinuity shown as a large fault on the form-line map. On the form-line map, east–west- and NE–SW-trending folds are abundant and NW–SE-trending ones occur locally in both complexes. North–south-trending folds are also abundant in the Napier Complex. Dome-and-basin fold patterns on a regional scale occur in some regions. The regional strikes, macroscopic structures, and the major boundary between the two complexes are considered to have resulted from the same later deformation episode. The form-line map and distribution map of key mineral assemblages show that the Napier Complex is not uniform and includes at least two types of metamorphic units or fragments of the Archaean crust that were formed through distinct
P
–
T
–
t
evolutionary processes and divided by several faults.
Pre-metamorphic carbon, oxygen and strontium isotope signature of high-grade marbles from the Lützow-Holm Complex, East Antarctica: apparent age constraints of carbonate deposition
Authors: Satish-Kumar M. , Miyamoto T. , Hermann J. , Kagami H. , Osanai Y. , Motoyoshi Y. 
Published: November 2008

Abstract

C, O and Sr isotope geochemistry of high-grade marbles from the Lützow-Holm Complex, East Antarctica, has given clues on the depositional ages and post-depositional alterations. Dolomitic and calcitic marbles occur as thin layers with varying thickness (up to 100 m) in several outcrops in eastern Dronning Maud Land, most of which underwent post-depositional geochemical alterations. In particular, the Sr and O isotope alterations are extensive, with
87
Sr/
86
Sr
(550 Ma)
ratios as high as 0.758 and δ
18
O values as low as −5‰. These data suggest that multiple stages of fluid–rock interaction processes during diagenesis, prograde to peak and retrograde metamorphic events have altered the depositional isotopic signatures. However, some of the marble layers, exceptionally, preserve pre-metamorphic geochemical characteristics, such as low Sr isotope ratios, high δ
18
O and δ
13
C values, and well-equilibrated unaltered trace and rare earth element patterns. Lowest
87
Sr/
86
Sr isotopic ratios of 0.7066 and 0.7053 with high δ
13
C and δ
18
O values suggest an apparent age of deposition around 730–830 Ma, although total geochemical resetting of carbonates by seawater of this age cannot be ruled out. The apparent depositional ages are consistent with carbonate deposition in the ‘Mozambique Ocean’ that separated East and West Gondwana.
Elastic properties of high-grade metamorphosed igneous rocks from Enderby Land and eastern Dronning Maud Land, Antarctica: evidence for biotite-bearing mafic lower crust
Authors: Ishikawa M. , Shingai E. , Arima M. 
Published: November 2008

Abstract

Ultrasonic measurements of P-wave velocity (
V
p
) and S-wave velocity (
V
s
) were conducted at high pressures up to 1.0 GPa and high temperatures up to 400 °C for ultrahigh-temperature (UHT) metamorphosed rocks from Mount Riiser-Larsen, in the Archaean Napier Complex of Enderby Land. The results at 1.0 GPa and 400 °C are
V
p
=7.17 km s
−1
,
V
s
=4.24 km s
−1
,
V
p
/
V
s
=1.69, Poisson's ratio (σ)=0.23 for pyroxenite (SiO
2
=44.2 wt%, density (ρ)=3.41 g cm
−3
);
V
p
=6.93 km s
−1
,
V
s
=3.81 km s
−1
,
V
p
/
V
s
=1.82, σ=0.28 for mafic granulite (SiO
2
=52.2 wt%, ρ=3.02 g cm
−3
);
V
p
=6.88 km s
−1
,
V
s
=3.72 km s
−1
,
V
p
/
V
s
=1.85, σ=0.29 for mafic granulite (SiO
2
=49.5 wt%, ρ=2.88 g cm
−3
); and
V
p
=6.17 km s
−1
,
V
s
=3.59 km s
−1
,
V
p
/
V
s
=1.72, σ=0.24 for orthopyroxene-bearing felsic gneiss (SiO
2
=65.4 wt%, ρ=2.68 g cm
−3
).
V
p
and
V
p
/
V
s
of these UHT rocks are not comparable with the previously proposed seismic velocity model (
V
p
=6.56 km s
−1
,
V
p
/
V
s
=1.70) for the lower crust beneath the Mizuho Plateau of eastern Dronning Maud Land. Combining the available measured velocity and density data with the seismic velocity profile defined for the Mizuho Plateau, we suggest that relatively low
V
p
and
V
s
characteristics of the lower crust beneath the Mizuho Plateau may be attributed to higher abundance of biotite in the mafic lower crustal rocks. It is proposed that the biotite-bearing lower crustal rocks were formed by metasomatic processes associated with Pan-African orogeny.
Acrolein health effects
Authors: Faroon O , Roney N , Taylor J , Ashizawa A , Lumpkin MH , Plewak DJ 
Published: November 2008

AbstractAcrolein is a chemical used as an intermediate reactive aldehyde in chemical industry. It is used for synthesis of many organic substances, methionine production, and methyl chloride refrigerant. The general population is exposed to acrolein via smoking, second-hand smoke, exposure to wood and plastic smoke. Firefighters and population living or working in areas with heavy automotive traffic may expose to higher level of acrolein via inhalation of smoke or automotive exhaust. Degradation of acrolein in all environmental media occurs rapidly, therefore, environmental accumulation is not expected. Acrolein degrade in 6 days when applied to surface water, and it has not been found as a contaminant in municipal drinking water. Acrolein vapor may cause eye, nasal and respiratory tract irritations in low level exposure. A decrease in breathing rate was reported by volunteers acutely exposed to 0.3 ppm of acrolein. At similar level, mild nasal epithelial dysplasia, necrosis, and focal basal cell metaplasia have been observed in rats. The acrolein effects on gastrointestinal mucosa in the animals include epithelial hyperplasia, ulceration, and hemorrhage. The severity of the effects is dose dependent. Acrolein induces the respiratory, ocular, and gastrointestinal irritations by inducing the release of peptides in nerve terminals innervating these systems. Levels of acrolein between 22 and 249 ppm for 10 min induced a dose-related decrease in substance P (a short-chain polypeptide that functions as a neurotransmitter or neuromodulator).
LineageSpecificSeqgen: generating sequence data with lineage-specific variation in the proportion of variable sites
Authors: Shavit Grievink Liat , Penny David , Hendy Mike D , Holland Barbara R 
Published: November 2008

Abstract

Background
Commonly used phylogenetic models assume a homogeneous evolutionary process throughout the tree. It is known that these homogeneous models are often too simplistic, and that with time some properties of the evolutionary process can change (due to selection or drift). In particular, as constraints on sequences evolve, the proportion of variable sites can vary between lineages. This affects the ability of phylogenetic methods to correctly estimate phylogenetic trees, especially for long timescales. To date there is no phylogenetic model that allows for change in the proportion of variable sites, and the degree to which this affects phylogenetic reconstruction is unknown.

Results
We present LineageSpecificSeqgen, an extension to the seq-gen program that allows generation of sequences with both changes in the proportion of variable sites and changes in the rate at which sites switch between being variable and invariable. In contrast to seq-gen and its derivatives to date, we interpret branch lengths as the mean number of substitutions per variable site, as opposed to the mean number of substitutions per site (which is averaged over all sites, including invariable sites). This allows specification of the substitution rates of variable sites, independently of the proportion of invariable sites.

Conclusion
LineageSpecificSeqgen allows simulation of DNA and amino acid sequence alignments under a lineage-specific evolutionary process. The program can be used to test current models of evolution on sequences that have undergone lineage-specific evolution. It facilitates the development of both new methods to identify such processes in real data, and means to account for such processes. The program is available at: http://awcmee.massey.ac.nz/downloads.htm.
Factorized spread sets and translation planes with large homology groups
Authors: Dempwolff Ulrich , Müller Peter 
Published: November 2008

Abstract
In this note we construct some series of translation planes of order q
2 which possess two commuting homology groups of order q – 1 and (q + 1)(q – 1, 2) respectively. These translation planes can be considered as relatives of nearfield planes: for nearfield planes the nontrivial part of the associated spread set is a group whereas in our case this set is the product of two groups.
The political economy of Croatian television: Exploring the impact of Latin American telenovelas
Authors: Vujnovic Marina 
Published: November 2008

Abstract
This article explores the implications of the emerging new players in the global arena of telenovelas. Latin American telenovelas have had phenomenal success in the post-communist countries of Eastern Europe. There has been an effort to localize the genre of telenovelas in some of those countries. The Croatian case emerges as a specific example because of its recent trend in the domestic production of telenovelas. Studying the political-economic aspect of this imported genre by examining debates surrounding the domestically produced Villa Maria could help us understand some of the logic of the global media flow.
Given the commercial development of broadcasting and the subsequent rise of U.S.- and Latin American-produced fiction, this article is an analysis of the political-economic and globalization debates that emerged in the Croatian press around domestically produced telenovela Villa Maria.
Mechanical Properties of High Strength Concrete with Field-Demolished Concrete as Aggregates
Authors: Liu Juanyu , Chen Bing 
Published: November 2008

Abstract
Environmental and economic factors are increasingly encouraging higher value utilization of demolition debris. While the use of recycled concrete aggregate (RCA) is confined mainly to low-grade application, it would be more beneficial if high strength concrete (HSC) can be produced with demolished concrete for new concrete construction. Hence, an experimental study was undertaken to explore the feasibility and potential of using field-demolished concrete as full replacement of natural aggregates to produce HSC, as reported in this paper. The workability of fresh concrete and mechanical properties of hardened concrete made with RCAs were investigated. The preliminary results indicated that HSC with up to 80 MPa of 28-day compressive strength made with field-demolished concrete as coarse aggregate and natural sand as fine aggregate can be obtained with the facilitation of a modified mixing method and the addition of silica fume. By providing a general basis for evaluating demolished concrete as aggregates for HSC, the investigation reported herein should contribute significantly to the understanding of recycled aggregate concrete as a viable option in the HSC construction industry.
Nonsurgical Management of Posterior Tibial Tendon Dysfunction With Orthoses and Resistive Exercise: A Randomized Controlled Trial
Authors: Kulig Kornelia , Reischl Stephen F , Pomrantz Amy B , Burnfield Judith M , Mais-Requejo Susan , Thordarson David B , Smith Ronald W 
Published: November 2008

Background and PurposeTibialis posterior tendinopathy can lead to debilitating dysfunction. This study examined the effectiveness of orthoses and resistance exercise in the early management of tibialis posterior tendinopathy.SubjectsThirty-six adults with stage I or II tibialis posterior tendinopathy participated in this study.MethodsParticipants were randomly assigned to 1 of 3 groups to complete a 12-week program of: (1) orthoses wear and stretching (O group); (2) orthoses wear, stretching, and concentric progressive resistive exercise (OC group); or (3) orthoses wear, stretching, and eccentric progressive resistive exercise (OE group). Pre-intervention and post-intervention data (Foot Functional Index, distance traveled in the 5-Minute Walk Test, and pain immediately after the 5-Minute Walk Test) were collected.ResultsFoot Functional Index scores (total, pain, and disability) decreased in all groups after the intervention. The OE group demonstrated the most improvement in each subcategory, and the O group demonstrated the least improvement. Pain immediately after the 5-Minute Walk Test was significantly reduced across all groups after the intervention.Discussion and ConclusionPeople with early stages of tibialis posterior tendinopathy benefited from a program of orthoses wear and stretching. Eccentric and concentric progressive resistive exercises further reduced pain and improved perceptions of function.