bluuebunny/crossref_metadata_2025_split huggingface dataset:
Chapter 31 A Palaeozoic NW Passage and the Timanian, Caledonian and Uralian connections of some exotic terranes in the North American Cordillera
Authors: Colpron Maurice , Nelson Joanne L. 
Published: August 2011

Abstract
Exotic terranes of inferred Arctic affinity form an outer belt within the North American Cordillera extending from Alaska to northern California. The geological history, fossil and detrital zircon data for these terranes show strong correlations and linkages among them, and many features in common with the northern Caledonides, the Timanide orogen and the Urals. They probably occupied an intermediate position between Baltica, Laurentia and Siberia, in proximity to the northern Caledonides in Early Palaeozoic time. Westward dispersion of these terranes is interpreted to result from development of a Scotia-style subduction system between Laurentia–Baltica and Siberia in Mid-Palaeozoic time – the NW Passage – following closure of the Iapetus ocean. Diachronous orogenic activity from Late Silurian in Arctic Canada to Early Devonian in north Yukon and Alaska records passage of some of these terranes. Westward propagation of a narrow subduction zone coupled with a global change in plate motion, linked to closure of the Rheic Ocean are proposed to have led to initiation of subduction along the western margin of Laurentia. This is recorded by the Late Devonian initiation of arc magmatism along western Laurentia, and the Late Devonian–Early Mississippian Antler orogeny in the western US and Ellesmerian orogeny in the Canadian Arctic.
Chapter 33 Stratigraphic and tectonic framework of the US Chukchi Shelf: exploration insights from a new regional deep-seismic reflection survey
Authors: Kumar Naresh , Granath J. W. , Emmet P. A. , Helwig J. A. , Dinkelman M. G. 
Published: August 2011

Abstract

The US Chukchi Shelf is a proven petroleum province similar to the prolific hydrocarbon-bearing region in the adjacent North Slope of Alaska. This shelf is part of the Arctic Alaska plate that was presumably connected to the Canadian Arctic Islands until the opening of the Canada Basin. A new data set (3130 km) of deep 2D seismic reflection profiles, acquired in 2006 and depth processed to 40 km, provides excellent images of the drillable (
c
. 8 km depth) stratigraphy as well as of deeper structures. The data also permit regional mapping of the tops of crystalline basement and the Moho discontinuity. The area has a tectonic history of multiple phases of rifting: a pre-Late Devonian phase that culminated in inversion and thrusting; a Late Devonian–Mississippian phase that accommodated Ellesmerian sedimentary deposits as a sag sequence; and a Jurassic to Early Cretaceous phase that is contemporaneous with the opening of the Canada Basin. Hanna Trough is recognized as a Palaeozoic basin with a multistage history while the North Chukchi Basin formed in early Cretaceous as an extensional basin. Only five wells have been drilled in the area; hence numerous opportunities for further exploration exist in the Chukchi Shelf.
Chapter 39 Using discovery process and accumulation volumetric models to improve petroleum resource assessment in Sverdrup Basin, Canadian Arctic Archipelago
Authors: Chen Zhuoheng , Osadetz Kirk G. 
Published: August 2011

Abstract

Sverdrup Basin hosts a structural petroleum play in Mesozoic clastic reservoirs. Twenty-one discovered fields (eight crude oil and 25 natural gas pools) have 294.1×10
6
m
3
crude oil, and 500.3×10
9
m
3
natural gas, original in-place contingent resources. We discuss and compare discovery process and volumetric assessment methods that, respectively, predict a 673.1×10
6
m
3
or 698.7×10
6
m
3
median crude oil resource and a 1187.4×10
9
m
3
or 1202.8×10
9
m
3
median natural gas resource. Both methods predict that the largest crude oil and third-largest natural gas pools are undiscovered, a result inferred to be consistent with available data and the exploration history. Volumetric assessments can precede any discoveries and they use common geoscience data inputs; however, they can be affected by data interdependencies and biases from exploratory sampling and subjective parameter estimates, particularly those affecting the number of accumulations. Discovery process methods solve for the accumulation numbers and size distribution simultaneously, accounting for sampling bias and free of data interdependencies, but only once sufficient discoveries exist. The Sverdrup Basin dataset and exploration history permit us to cross-validate volumetric and discovery process assessments and validate their predictions, for example undiscovered pool sizes, against a regional geoscience dataset. The discovery process results agree well with geoscience constraints, but the initial volumetric assessment must be restricted to predict undiscovered pool sizes consistent with the geoscience dataset. Our analysis illustrates advantages and potential pitfalls for volumetric and discovery process assessments and shows that cross-validation between methods and against available data constrains resource potentials and improves confidence in result.
Chapter 44 Geology and petroleum potential of the Lincoln Sea Basin, offshore North Greenland
Authors: Sørensen Kai , Gautier Don , Pitman Janet , Jackson H. Ruth , Dahl-Jensen Trine 
Published: August 2011

Abstract

A seismic refraction line crossing the Lincoln Sea was acquired in 2006. It proves the existence of a deep sedimentary basin underlying the Lincoln Sea. This basin appears to be comparable in width and depth to the Sverdrup Basin of the Canadian Arctic Islands. The stratigraphy of the Lincoln Sea Basin is modelled in analogy to the Sverdrup Basin and the Central Spitsbergen Basin, two basins between which the Lincoln Sea intervened before the onset of seafloor spreading in the Eurasian Basin. The refraction data indicates that the Lincoln Sea Basin is capped by a kilometre-thick, low-velocity layer, which is taken to indicate an uplift history similar to, or even more favourable than, the fairway part of the Sverdrup Basin. Tectonic activity in the Palaeogene is likely to constitute the major basin scale risk. We conclude that the Lincoln Sea Basin is likely to be petroliferous and contains risked resources on the order of 1×10
9
barrels of oil, to which comes an equivalent amount of (associated and nonassociated) gas.
Chapter 48 Geology and petroleum potential of the Eurasia Basin
Authors: Moore Thomas E. , Pitman Janet K. 
Published: August 2011

Abstract

The Eurasia Basin petroleum province comprises the younger, eastern half of the Arctic Ocean, including the Cenozoic Eurasia Basin and the outboard part of the continental margin of northern Europe. For the USGS petroleum assessment (CARA), it was divided into four assessment units (AUs): the Lena Prodelta AU, consisting of the deep-marine part of the Lena Delta; the Nansen Basin Margin AU, comprising the passive margin sequence of the Eurasian plate; and the Amundsen Basin and Nansen Basin AUs which encompass the abyssal plains north and south of the Gakkel Ridge spreading centre, respectively. The primary petroleum system thought to be present is sourced in
c
. 50–44 Ma (Early to Middle Eocene) condensed pelagic deposits that could be widespread in the province. Mean estimates of undiscovered, technically recoverable petroleum resources include <1 billion barrels of oil (BBO) and about 1.4 trillion cubic feet (TCF) of nonassociated gas in Lena Prodelta AU, and <0.4 BBO and 3.4 TCF nonassociated gas in the Nansen Basin Margin AU. The Nansen Basin and Amundsen Basin AUs were not quantitatively assessed because they have less than 10% probability of containing at least one accumulation of 50 MMBOE (million barrels of oil equivalent).
Chapter 5 Palaeogeographic and tectonic evolution of the Arctic region during the Palaeozoic
Authors: Lawver Lawrence A. , Gahagan Lisa M. , Norton Ian 
Published: August 2011

Abstract
The Palaeozoic motion of the future Arctic continents is presented in the animation found in the accompanying CD-ROM. The animation shows snapshots of the motion of the tectonic blocks from 550 to 250 Ma in 3 million year steps. The locations of the blocks are controlled mainly by palaeomagnetic pole values for the blocks tied to known geological events, particularly the three main Arctic orogenies: the Scandian Caledonian which began in the Silurian, the Ellesmerian in the Late Devonian and the Uralian that began in the Late Pennsylvanian. Perhaps the most significant observation to come out of the animation is that the future Arctic continents were never very far from one another during the Palaeozoic. The maximum distance from Baltica to Laurentia may have reached 6000 km during the Middle Cambrian but the Arctic continents all surrounded the same eastern Iapetus Ocean and, by Silurian, they were quite close. Reliance on the ‘Y-loop’ palaeomagnetic data causes extremely rapid motion of Gondwana during the Silurian. Consequently the ‘X-path’ for that period is used. The palaeomagnetic poles for 422 and 406 Ma have been eliminated so that Gondwana motion is within the bounds of present day plate motion.

Supplementary material:

A Quicktime™ movie of palaeogeographic and tectonic evolution of the Arctic region during the Palaeozoic is available at
http://www.geolsoc.org.uk/SUP18472
.
Chapter 6 Phanerozoic palaeoenvironment and palaeolithofacies maps of the Arctic region
Authors: Golonka Jan 
Published: August 2011

Abstract
Sixty-three maps illustrate geodynamic evolution and development of palaeoenvironments and palaeolithofacies of the Circum-Arctic region during Phanerozoic times. After the break-up of Rodinia and Pannotia in the Early Palaeozoic, the major Arctic plates Baltica, Siberia and Laurentia drifted from their original position around the South Pole towards the Supercontinent Pangea, which existed in the equatorial position during Late Palaeozoic and Early Mesozoic times. During the Mesozoic and Cenozoic plates gathered around newly formed Arctic Ocean. Large continental masses were assembled from major plates and numerous small plates and terranes on the northern hemisphere and around the North Pole. All the continents were by now connected. Carbonates were abundant in Siberia and Laurentia during Palaeozoic times. Clastic sedimentation prevailed during Mesozoic and Cenozoic times. The distribution of lithofacies shows climatic change associated with continental assembly and disassembly as well as with the steady northward drift of the continents.
Chapter 7 Hydrocarbon finds in the Arctic basins: discovery history, discovered resources and petroleum systems
Authors: Chew Kenneth J. , Arbouille Didier 
Published: August 2011

Abstract
Over the past 75 years, hydrocarbon exploration of Arctic regions north of the Arctic Circle (66°N) has yielded some 450 discoveries which collectively account for 2.5% of global conventional liquids discovered to date and 15.5% of the world's discovered conventional natural gas. Accumulations occur in rocks ranging from Cambrian to Pleistocene in age but 94% of all Arctic hydrocarbon resources occur in clastic reservoirs of Mesozoic age. Although discoveries have been reported from 15 different basins onshore and offshore Alaska, Canada, Norway and Russia, 75% of all discovered resources are located in the portion of Russia's Western Siberia Basin that lies north of 66°N. Hydrocarbon accumulations discovered in the Arctic region have been generated from nearly 40 different petroleum systems. The main elements of these petroleum systems such as sources, reservoirs and seals are described and the chronology of these depositional events is summarized in two chronologic charts representing the Eastern and Western hemispheres.
Macrophage Elovl6 Deficiency Ameliorates Foam Cell Formation and Reduces Atherosclerosis in Low-Density Lipoprotein Receptor-Deficient Mice
Authors: Saito Ryo , Matsuzaka Takashi , Karasawa Tadayoshi , Sekiya Motohiro , Okada Nazuki , Igarashi Masaki , Matsumori Rie , Ishii Kiyoaki , Nakagawa Yoshimi , Iwasaki Hitoshi , Kobayashi Kazuto , Yatoh Shigeru , Takahashi Akimitsu , Sone Hirohito , Suzuki Hiroaki , Yahagi Naoya , Yamada Nobuhiro , Shimano Hitoshi 
Published: August 2011

Objective—
Elovl6, a long-chain fatty acid elongase, is a rate-limiting enzyme that elongates saturated and monounsaturated fatty acids and has been shown to be related to obesity-induced insulin resistance via modification of fatty acid composition. In this study, we investigated the roles of Elovl6 in foam cell formation in macrophages and atherosclerosis in mice.

Methods and Results—

To investigate the roles of Elovl6 in macrophages in the progression of atherosclerosis, we transplanted bone marrow cells of wild-type or Elovl6
−/−
mice into irradiated LDL-R
−/−
mice that were fed a western diet. Aortic atherosclerotic lesion areas and infiltration of macrophages were significantly smaller in Elovl6
−/−
bone marrow cells-transplanted LDL-R
−/−
mice than in wild-type. Accumulation of esterified cholesterol on exposure to acetylated-LDL was less severe in peritoneal macrophages from Elovl6
−/−
mice than those from wild-type. Cholesterol efflux and expression of cholesterol efflux transporters were increased in Elovl6
−/−
macrophages, although no difference in uptake of acetylated-LDL was found between the two groups. On analysis of fatty acid composition of the esterified cholesterol fraction in macrophages, n-6 polyunsaturated fatty acids were decreased by absence of Elovl6.

Conclusion—
These findings suggest that Elovl6 in macrophages may contribute to foam cell formation and progression of atherosclerosis.
Human Neutrophil Peptides Mediate Endothelial-Monocyte Interaction, Foam Cell Formation, and Platelet Activation
Authors: Quinn Kieran L. , Henriques Melanie , Tabuchi Arata , Han Bing , Yang Hong , Cheng Wei-Erh , Tole Soumitra , Yu Hanpo , Luo Alice , Charbonney Emmanuel , Tullis Elizabeth , Lazarus Alan , Robinson Lisa A. , Ni Heyu , Peterson Blake R. , Kuebler Wolfgang M. , Slutsky Arthur S. , Zhang Haibo 
Published: August 2011

Objective—
Neutrophils are involved in the inflammatory responses during atherosclerosis. Human neutrophil peptides (HNPs) released from activated neutrophils exert immune modulating properties. We hypothesized that HNPs play an important role in neutrophil-mediated inflammatory cardiovascular responses in atherosclerosis.

Methods and Results—
We examined the role of HNPs in endothelial-leukocyte interaction, platelet activation, and foam cell formation in vitro and in vivo. We demonstrated that stimulation of human coronary artery endothelial cells with clinically relevant concentrations of HNPs resulted in monocyte adhesion and transmigration; induction of oxidative stress in human macrophages, which accelerates foam cell formation; and activation and aggregation of human platelets. The administration of superoxide dismutase or anti-CD36 antibody reduced foam cell formation and cholesterol efflux. Mice deficient in double genes of low-density lipoprotein receptor and low-density lipoprotein receptor–related protein (LRP), and mice deficient in a single gene of LRP8, the only LRP phenotype expressed in platelets, showed reduced leukocyte rolling and decreased platelet aggregation and thrombus formation in response to HNP stimulation.

Conclusion—
HNPs exert proatherosclerotic properties that appear to be mediated through LRP8 signaling pathways, suggesting an important role for HNPs in the development of inflammatory cardiovascular diseases.
Proteasomal Inhibition Promotes ATP-Binding Cassette Transporter A1 (ABCA1) and ABCG1 Expression and Cholesterol Efflux From Macrophages In Vitro and In Vivo
Authors: Ogura Masatsune , Ayaori Makoto , Terao Yoshio , Hisada Tetsuya , Iizuka Maki , Takiguchi Shunichi , Uto-Kondo Harumi , Yakushiji Emi , Nakaya Kazuhiro , Sasaki Makoto , Komatsu Tomohiro , Ozasa Hideki , Ohsuzu Fumitaka , Ikewaki Katsunori 
Published: August 2011

Objective—
ATP-binding cassette transporter A1 (ABCA1) and ABCG1 are key molecules in an initial step of reverse cholesterol transport (RCT), a major antiatherogenic property of high-density lipoprotein (HDL). The ubiquitin-proteasome system (UPS) mediates nonlysosomal pathways for protein degradation and is known to be involved in atherosclerosis. However, little is known about the effects of the UPS on these molecules and overall RCT. We therefore investigated whether UPS inhibition affects ABCA1/G1 expression in macrophages and RCT in vitro and in vivo.

Methods and Results—

Various proteasome inhibitors increased ABCA1/G1 expression in macrophages, translating into enhanced apolipoprotein A-I– and HDL-mediated cholesterol efflux from macrophages. ABCA1 and ABCG1 were found to undergo polyubiquitination in the macrophages and HEK293 cells overexpressing these proteins, and pulse-chase analysis revealed that proteasome inhibitors inhibited ABCA1/G1 protein degradation. In in vivo experiments, the proteasome inhibitor bortezomib increased ABCA1/G1 protein levels in mouse peritoneal macrophages, and RCT assays showed that it significantly increased the fecal (54% increase compared with saline) and plasma (23%) appearances of the tracer derived from intraperitoneally injected
3
H-cholesterol-labeled macrophages.

Conclusion—
The present study provided evidence that the UPS is involved in ABCA1/G1 degradation, thereby affecting RCT in vivo. Therefore, specific inhibition of the UPS pathway might lead to a novel HDL therapy that enhances RCT.
Interactions Between Smoking, Pulmonary Surfactant Protein B, and Atherosclerosis in the General Population
Authors: Nguyen Ann B. , Rohatgi Anand , Garcia Christine K. , Ayers Colby R. , Das Sandeep R. , Lakoski Susan G. , Berry Jarett D. , Khera Amit , McGuire Darren K. , de Lemos James A. 
Published: August 2011

Objective—
Pulmonary surfactant protein B (SP-B), an alveolar protein normally detectable at only very low concentrations in blood, circulates at higher levels among smokers and those with alveolar injury and inflammation. We hypothesized that SP-B may serve as a marker of the vascular effects of smoking and would thus be associated with subclinical measures of atherosclerosis.

Methods and Results—

Plasma levels of SP-B were measured in 3294 subjects, ages 30 to 65, enrolled in the Dallas Heart Study, a probability-based population sample of Dallas County adults. Coronary artery calcium (CAC) was measured by computed tomography and abdominal aortic plaque (AP) by magnetic resonance imaging. The cohort comprised 29% current and 17% former smokers. The overall prevalence of CAC was 22%, and that of AP was 39%. Median SP-B levels were 5-fold higher among current versus never smokers (
P
<0.0001) and were significantly correlated with estimated pack-years smoked (Spearman ρ=0.35,
P
<0.0001). Increasing levels of SP-B also associated with other traditional cardiac risk factors and higher levels of inflammatory biomarkers. In univariable analyses, increasing SP-B quartiles associated with higher prevalence of both CAC and AP (
P
trend
<0.0001 for each). In multivariable analyses adjusting for traditional cardiovascular risk factors, SP-B remained associated with AP (OR 1.87 for the 4th versus 1st quartiles, 95% confidence interval 1.39 to 2.51;
P
<0.0001) but not CAC. An interaction was observed between SP-B, smoking status, and AP (
P
interaction
=0.01), such that SP-B associated with AP in current smokers (adjusted OR 2.15 for the 4th versus 1st quartile, 95% confidence interval 1.26 to 3.67;
P
=0.005) but not in former or never smokers.

Conclusion—
Circulating levels of SP-B increase with greater smoking burden and independently associate with abdominal AP among current smokers. Our findings support further investigation of the role of SP-B as a marker of the vascular effects of smoking.
Orally Administered Eicosapentaenoic Acid Induces Rapid Regression of Atherosclerosis Via Modulating the Phenotype of Dendritic Cells in LDL Receptor-Deficient Mice
Authors: Nakajima Kenji , Yamashita Tomoya , Kita Tomoyuki , Takeda Masafumi , Sasaki Naoto , Kasahara Kazuyuki , Shinohara Masakazu , Rikitake Yoshiyuki , Ishida Tatsuro , Yokoyama Mitsuhiro , Hirata Ken-ichi 
Published: August 2011

Objective—
Eicosapentaenoic acid (EPA) has been shown to have beneficial effects on cardiovascular diseases, although the precise mechanism is unknown. We investigated the effect of EPA on the regression of atherosclerosis.

Methods and Results—

LDL-receptor–deficient mice were fed a high-cholesterol diet for 8 weeks to build up aortic sinus atherosclerotic lesions and then were fed a normal diet with or without 5% EPA for 4 weeks. Atherosclerotic lesions were histologically assessed, and immunologic assays were performed. EPA treatment significantly regressed atherosclerosis (−22.7%,
P
<0.05) and decreased the content of macrophages, CD4
+
T cells, and dendritic cells (DCs) in atherosclerotic lesions, though only changing the chow never induced the regression. Flow cytometric analysis revealed that EPA increased immature DCs (CD11c
+
CD80
−
CD86
−
), increased the indoleamine 2,3-dioxygenase (IDO) in DCs, and decreased the number of CD4
+
T cells. In the presence of the IDO inhibitor, the beneficial effects of EPA on regression were inhibited, suggesting that the effect of EPA was mainly mediated through IDO.

Conclusion—
In addition to lowering plasma cholesterol, EPA regressed atherosclerosis probably due to modulation of DC phenotype and reduction in T cell numbers. The present findings might partly explain the beneficial effects of EPA in clinics and support clinical evidence.
Interleukin-10 Released by CD4
+
CD25
+
Natural Regulatory T Cells Improves Microvascular Endothelial Function Through Inhibition of NADPH Oxidase Activity in Hypertensive Mice
Authors: Kassan Modar , Galan Maria , Partyka Megan , Trebak Mohamed , Matrougui Khalid 
Published: August 2011

Objective—

We previously demonstrated that a reduced number of CD

4
+

CD

25
+

-regulatory T cells (Tregs) was associated with microvascular dysfunction in hypertension. However, the underlying mechanism by which Tregs regulate vascular endothelial function remains unknown.

Methods and Results—

Control and interleukin (IL)-10
−/−
knockout mice were infused with angiotensin II (400 ng/kg/min) for 2 weeks (hypertensive [HT] and HT-IL-10
−/−
). Endothelium-dependent relaxation (EDR) in response to acetylcholine was significantly reduced in mesenteric resistance artery (MRA) from HT and HT-IL-10
−/−
compared with control and IL-10
−/−
mice. Importantly, the incubation of MRA from HT mice with the conditioned media of cultured Tregs, isolated from control mice, reduced NADPH oxidase activity and improved EDR, whereas no effect was observed in MRA from control mice incubated with the same media. These effects were reversed when MRAs were preincubated with IL-10 antibody or IL-10 receptor antagonist, whereas incubation with transforming growth factor-β receptor antagonist had no effect. The transfer of cultured Tregs, isolated from control mice, into HT-IL-10
−/−
mice reduced systolic blood pressure (SBP) and NADPH oxidase activity and improved EDR in MRA compared with untreated HT-IL-10
−/−
mice. In vivo treatment of HT mice with IL-10 (1000 ng/mouse) significantly reduced SBP and NADPH oxidase activity and improved EDR in MRA compared with untreated HT mice. The transfer of cultured Tregs, isolated from IL-10
−/−
mice, into HT mice did not reduce SBP or NADPH oxidase activity or improve EDR. The incubation of MRA from HT mice with apocynin improved EDR, whereas NADPH oxidase substrate attenuated EDR in MRA from control mice, which was reversed with exogenous IL-10.

Conclusion—
These data demonstrate that IL-10 released from Tregs attenuates NADPH oxidase activity, which is a critical process in the improvement of microvascular endothelial function in hypertension, suggesting that Tregs/IL-10 could be a therapeutic target for treatment of vasculopathy in hypertension.