bluuebunny/crossref_metadata_2025 huggingface dataset:
Nanoscale capacitive behaviour of ion irradiated graphene on silicon oxide substrate
Authors: Sonde Sushant , Giannazzo Filippo , Raineri Vito , Rimini Emanuele
Published: December 2009

Single layers of graphene obtained by mechanical exfoliation of highly oriented pyrolytic graphite and deposited on a SiO2/n+‐Si substrate were irradiated with high‐energy (500 keV) C ions. Controlled amounts of defects were introduced in graphene by a precise control of the ion fluence, ranging from 1 × 1013 to 1 × 1014 cm−2. Scanning capacitance spectroscopy (SCS) was used as non‐destructive characterization technique to probe the effect of irradiation defects on the electrical properties of graphene. A wider variation between the capacitance curves measured at different positions on irradiated graphene is found in comparison with the pristine graphene. The quantum capacitance per unit area $C'_{\rm q} $ was extracted from raw data. In particular, an increase of $C'_{\rm q} $ is associated to the damaged regions.
Electron impact ionization in K‐, L‐, and M‐shells of atomic targets
Authors: Patoary M. A. R. , Uddin M. Alfaz , Haque A. K. F. , Shahjahan M. , Basak A. K. , Saha B. C.
Published: December 2009

Recently proposed extension of the empirical model (BELL) of Bell et al. (J Phys Chem Ref Data 1983, 12, 891) with incorporation of the quantum mechanical form of orbital radius from the DM model and a nonlinear feature in addition to the ionic and relativistic corrections is examined for electron‐impact single ionization in the K‐, L‐, and M‐shells of ionic and neutral atoms. This leads to the generalization of the parameters of the nonlinear form of the modified BELL (NMBELL) model in terms of the quantum numbers nl of the ionizing orbits. The generalization shows that only three species‐independent fitting parameters, dependent only on the orbitals, in the NMBELL model satisfactorily reproduce the electron‐impact single ionization cross sections of 42 ionic targets belonging to the He, Li, Be, B, C, O, F, Ne, Mg, Al, P, Ca, and Sc isoelectronic sequences over a wide range of energies up to 200 MeV. The NMBELL model is also found to well account for the L‐ and M‐shell ionization of six neutral atoms up to 1 GeV. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2011
Gaussian process learning for cyber‐attack early warning
Authors: Zhang Jian , Porras Phillip , Ullrich Johannes
Published: December 2009

Network security has been a serious concern for many years. For example, firewalls often record thousands of exploit attempts on a daily basis. Network administrators could benefit from information on potential aggressive attack sources, as such information can help to proactively defend their networks. For this purpose, several large‐scale information sharing systems have been established, in which information on cyberattacks targeting each participant network is shared such that a network can be forewarned of attacks observed by others.

However, the total number of reported attackers is huge in these systems. Thus, a challenging problem is to identify the attackers that are most relevant to each individual network (i.e. most likely to come to that network in the near future). We present a framework to estimate the relevance of each attacker with respect to each network. In particular, we model each attacker's relevance as a function over the networks. Different attackers have different functions. The distribution of the functions is modeled using a Gaussian process (GP). The relevance function of each attacker is then inferred from the GP, that itself is learned from the collection of attack information. We test our framework on the attack reports in the DShield information sharing system. Experiments show that attackers found relevant to a network by our framework are indeed more likely to come to that network in the future. Copyright © 2009 Wiley Periodicals, Inc. Statistical Analysis and Data Mining 3: 56‐68, 2010
Facilitating family group inquiry at science museum exhibits
Authors: Gutwill Joshua P. , Allen Sue
Published: December 2009

We describe a study of programs to deepen families' scientific inquiry practices in a science museum setting. The programs incorporated research‐based learning principles from formal and informal educational environments. In a randomized experimental design, two versions of the programs, called inquiry games, were compared to two control conditions. Inquiry behaviors were videotaped and compared at pretest and posttest exhibits. Family members were also interviewed about their perceptions and use of the inquiry games. Results indicated that visitors who learned the inquiry games improved their inquiry more than those who did not. Effect sizes ranged from 0.3σ to 0.7σ, depending on the assessment measure. Visitors who learned the collaborative inquiry game showed even more improvement than those who learned the individualized game, spending more time investigating the posttest exhibit, making more frequent and more abstract interpretations of their experiments, building more collaborative explanations, and engaging in more coherent inquiry investigations than controls. Qualitative analysis suggested that the collaborative inquiry game was superior because it required all family members to participate, work together, and explicitly articulate their interpretations. Visitors in all conditions enjoyed their experience, varied in what they liked and disliked, and reported applying what they had learned at new exhibits. © 2009 Wiley Periodicals, Inc. Sci Ed 94:710–742, 2010
Electrochemical Deposition of ZnO Nanorods on Transparent Reduced Graphene Oxide Electrodes for Hybrid Solar Cells
Authors: Yin Zongyou , Wu Shixin , Zhou Xiaozhu , Huang Xiao , Zhang Qichun , Boey Freddy , Zhang Hua
Published: December 2009

Monocrystalline ZnO nanorods (NRs) with high donor concentration are electrochemically deposited on highly conductive reduced graphene oxide (rGO) films on quartz. The film thickness, optical transmittance, sheet resistance, and roughness of rGO films are systematically studied. The obtained ZnO NRs on rGO films are characterized by X‐ray diffraction, transmission electron microscopy, photoluminescence, and Raman spectra. As a proof‐of‐concept application, the obtained ZnO NRs on rGO are used to fabricate inorganic–organic hybrid solar cells with layered structure of quartz/rGO/ZnO NR/poly(3‐hexylthiophene)/poly(3,4‐ethylenedioxythiophene):poly(styrenesulfonate) (P3HT/PEDOT:PSS)/Au. The observed power conversion efficiency (PCE, η), ≈ 0.31%, is higher than that reported in previous solar cells by using graphene films as electrodes. These results clearly demonstrate that rGO films with a higher conductivity have a smaller work function and show a better performance in the fabricated solar cells.
MicroRNA-204 Regulates Runx2 Protein Expression and Mesenchymal Progenitor Cell Differentiation
Authors: Huang Jian , Zhao Lan , Xing Lianping , Chen Di
Published: December 2009

Differentiation of mesenchymal stem cells into a particular lineage is tightly regulated, and malfunction of this regulation could lead to pathological consequences. Patients with osteoporosis have increased adipocyte accumulation, but the mechanisms involved remain to be defined. In this study, we aimed to investigate if microRNAs regulate mesenchymal progenitor cells and bone marrow stromal cell (BMSC) differentiation through modulation of Runx2, a key transcription factor for osteogenesis. We found that miR-204 and its homolog miR-211 were expressed in mesenchymal progenitor cell lines and BMSCs and their expression was induced during adipocyte differentiation, whereas Runx2 protein expression was suppressed. Retroviral overexpression of miR-204 or transfection of miR-204 oligo decreased Runx2 protein levels and miR-204 inhibition significantly elevated Runx2 protein levels, suggesting that miR-204 acts as an endogenous attenuator of Runx2 in mesenchymal progenitor cells and BMSCs. Mutations of putative miR-204 binding sites upregulated the Runx2 3′-UTR reporter activity, suggesting that miR-204/211 bind to Runx2 3′-UTR. Perturbation of miR-204 resulted in altered differentiation fate of mesenchymal progenitor cells and BMSCs: osteoblast differentiation was inhibited and adipocyte differentiation was promoted when miR-204 was overexpressed in these cells, whereasosteogenesis was upregulated and adipocyte formation was impaired when miR-204 was inhibited. Together, our data demonstrated that miR-204/211 act as important endogenous negative regulators of Runx2, which inhibit osteogenesis and promote adipogenesis of mesenchymal progenitor cells and BMSCs.
Loss of LAP2α Delays Satellite Cell Differentiation and Affects Postnatal Fiber-Type Determination
Authors: Gotic Ivana , Schmidt Wolfgang M. , Biadasiewicz Katarzyna , Leschnik Michael , Spilka Rita , Braun Juliane , Stewart Colin L. , Foisner Roland
Published: December 2009

Lamina-associated polypeptide 2α (LAP2α) is a nucleoplasmic protein implicated in cell cycle regulation through its interaction with A-type lamins and the retinoblastoma protein. Mutations in lamin A/C and LAP2α cause late onset striated muscle diseases, but the molecular mechanisms are poorly understood. To study the role of LAP2α in skeletal muscle function and postnatal tissue homeostasis, we generated complete and muscle-specific LAP2α knockout mice. Whereas overall muscle morphology, function, and regeneration were not detectably affected, the myofiber-associated muscle stem cell pool was increased in complete LAP2α knockout animals. At molecular level, the absence of LAP2α preserved the stem cell-like phenotype of Lap2α−/− primary myoblasts and delayed their in vitro differentiation. In addition, loss of LAP2α shifted the myofiber-type ratios of adult slow muscles toward fast fiber types. Conditional Cre-mediated late muscle-specific ablation of LAP2α affected early stages of in vitro myoblast differentiation, and also fiber-type determination, but did not change myofiber-associated stem cell numbers in vivo. Our data demonstrate multiple and distinct functions of LAP2α in muscle stem cell maintenance, early phases of myogenic differentiation, and muscle remodeling.
Deductive reasoning
Authors: Johnson‐Laird Phil
Published: December 2009

This article begins with an account of logic, and of how logicians formulate formal rules of inference for the sentential calculus, which hinges on analogs of negation and the connectivesif, or, andand. It considers the various ways in which computer scientists have written programs to prove the validity of inferences in this and other domains. Finally, it outlines the principal psychological theories of how human reasoners carry out deductions. Copyright © 2009 John Wiley & Sons, Ltd.

This article is categorized under:

Psychology > Reasoning and Decision Making
Attention and consciousness
Authors: De Brigard Felipe , Prinz Jesse
Published: December 2009

For the past three decades there has been a substantial amount of scientific evidence supporting the view that attention is necessary and sufficient for perceptual representations to become conscious (i.e., for there to be something that it is like to experience a representational perceptual state). This view, however, has been recently questioned on the basis of some alleged counterevidence. In this paper we survey some of the most important recent findings. In doing so, we have two primary goals. The first is descriptive: we provide a literature review for those seeking an understanding of the present debate. The second is editorial: we suggest that the evidence alleging dissociations between consciousness and attention is not decisive. Thus, this is an opinionated overview of the debate. By presenting our assessment, we hope to bring out both sides in the debate and to underscore that the issues here remain matters of intense controversy and ongoing investigation. Copyright © 2009 John Wiley & Sons, Ltd.

This article is categorized under:

Philosophy > Consciousness
Government–binding/principles and parameters theory
Authors: Lasnik Howard , Lohndal Terje
Published: December 2009

Principles and Parameters Theory is an approach to the study of the human language capacity based on an abstract underlying representation and operations called ‘transformations’ successively altering that structure. It has gradually evolved from the Government and Binding Theory to the Minimalist Program. Copyright © 2009 John Wiley & Sons, Ltd.

This article is categorized under:

Linguistics > Linguistic Theory
Hypo‐ and Hypernatraemia in Surgical Patients: Is There Room for Improvement?
Authors: Herrod Philip J. J. , Awad Sherif , Redfern Andrew , Morgan Linda , Lobo Dileep N.
Published: December 2009

Background

Up to 30% of surgical inpatients develop complications related to fluid and electrolyte therapy. We sought to study the occurrence of hypo‐ and hypernatraemia in these patients to inform current standards of care.

Methods

This prospective audit took place over 80 days in a university hospital. Patients with a serum sodium concentration less than 130 or greater than 150 mmol/l were included. Daily intakes of Na+, K+ and Cl−, and fluid balance were recorded before and after development of dysnatraemia. Fluid balance charts were assessed, as was the presence of documented patient weights. Patients were followed up until one of these milestones was reached: normonatraemia, death, or hospital discharge.

Results

During the study period 55 (4%) of the 1,383 surgical admissions met the inclusion criteria. Fifteen patients had hypernatraemia, 13 (87%) of whom were identified on ICU/HDU. In the days preceding the hypernatraemia, patients received (in mmol/day) a median (IQR) of 157 (76–344) Na+, 38 (6–65) K+, 157 (72–310) Cl−, and 1.96 (1.13–2.96) L water. In the days preceding the hyponatraemia, patients received 50 (0–189) Na+, 0 (0–10) K+, 56 (0–188) Cl−, and 1.45 (0–2.60) L water. Before the dysnatraemias only 28% of fluid balance charts were completed accurately. During the audit 42% of patients were not weighed. Dysnatraemic patients had a higher hospital mortality rate than those who did not develop dysnatraemia (12.7 vs. 2.3%, P < 0.001).

Conclusions

Four percent of surgical inpatients developed dysnatraemias, which were associated with increased mortality. Fluid balance documentation was suboptimal and daily weights were not measured routinely, even in patients with severe electrolyte derangements.
Resolving an Enhanced Oil Recovery Challenge: Optimum Formulation of a Surfactant‐Oil–Water System Made Insensitive to Dilution
Authors: Arandia María Antonieta , Forgiarini Ana María , Salager Jean‐Louis
Published: December 2009

Upon dilution by the petroleum reservoir connate water, the anionic commercial surfactant blend often used in enhanced oil recovery by low tension, becomes more lipophilic at the interface because of so‐called selective partitioning. Hence, the optimum formulation is not maintained when the injected slug moves through the reservoir. An opposite variation is found for ethoxylated nonionic surfactant systems. As a consequence of these antagonistic influences, the optimum formulation shift produced by dilution may be eliminated by using an appropriate mixture of anionic and nonionic commercial surfactants, so that the two effects exactly cancel out.
Interaction of mitochondrial potassium channels with the permeability transition pore
Authors: Cheng Yu , Debska-Vielhaber Grazyna , Siemen Detlef
Published: December 2009

Three types of potassium channels cooperate with the permeability transition pore (PTP) in the inner mitochondrial membranes of various tissues, mtK(ATP), mtBK, and mtKv1.3. While the latter two share similarities with their plasma membrane counterparts, mtK(ATP) exhibits considerable differences with the plasma membrane K(ATP)‐channel. One important function seems to be suppression of release of proapototic substances from mitochondria through the PTP. Open potassium channels tend to keep the PTP closed thus acting as antiapoptotic. Nevertheless, in their mode of action there are considerable differences among them. This review introduces three K+‐channels and the PTP, and discusses known facts about their interaction.
The media's role in shaping Canadian civic and political engagement
Authors: O’Neill Brenda
Published: December 2009

How does mediatised information affect attitudes and engagement in the civic/political spheres? The question is an important one, not only because of changing media forms but also because of the important role of the media in providing political information. As such, its intermediary role in shaping both political interest and political knowledge is heightened, both of which are important determinants of political engagement. This work uses the data from the 2003 General Social Survey to assess and compare variation in the effects of various media forms on civic engagement in Canada in order to provide a means of developing generalizable comparative claims regarding individual media effects. At the end, the author offers an assessment of what these findings suggest about the media's role in shaping engagement in Canada, particularly in the future.
Marine ice-rafting as a new type of sedimentogenesis in the Arctic and novel approaches to studying sedimentary processes
Authors: Lisitzin A.P.
Published: December 2009

Research on sedimentogenesis and geochemistry of the Arctic Ocean over the last 10–20 years has allowed direct (in situ) studies to be made for all types of sedimentary matter that mix together and form the bottom deposit. Contrary to common knowledge, river sediment turned out to be insignificant; instead, more important is the dispersed sedimentary matter (suspension) from the atmosphere, cryosphere (snow, ice), marine water, riverine water, biosphere (plankton and benthos), and anthroposphere (all types of pollutants), supplemented by the endogenic mater supplied from spreading zone of the Gakkel Ridge. The mixture is dominated by sedimentary material discharged from sea ice; hence, this type of sedimentogenesis is referred to as the ice-rafted marine sedimentogenesis.

Application of new methods and tools (including satellites, remote hydrooptical, hydrophysical, and hydroacoustic survey, etc.) and in situ analyses produced measurements of content, composition, and characteristics of all types of dispersed sedimentary matter, its fluxes (mg/m2/year), vectors of movement, and rates for different segments of the Arctic Ocean; observations were carried out continuously on different time scale, from hours–days to seasons and dozens of years. It is a new approach to the study of sedimentary matter that opens up new possibility for a 4D quantitative sedimentology.
Geology and hydrocarbon resources of the continental shelf in Russian Arctic seas and the prospects of their development
Authors: Kontorovich A.E. , Epov M.I. , Burshtein L.M. , Kaminskii V.D. , Kurchikov A.R. , Malyshev N.A. , Prischepa O.M. , Safronov A.F. , Stupakova A.V. , Suprunenko O.I.
Published: December 2009

The overall jump in global demand for gas, and especially oil, gives rise to particular concern regarding mankind’s energy future. In the middle and late 21st century, the crucial role in securing oil and gas supply of mankind will be played by sedimentary basins in the Arctic Ocean deep-water area, including those of the continental shelf in Russia’s Arctic seas. There is a 0.90 probability that the initial in-place resources of hydrocarbons in the Arctic Ocean will be greater than 90 Btoe. The estimates predict the rise of oil and gas industries on the Arctic shelves in the near future.
The superdeep North Chukchi Basin: formation by eclogitization of continental lower crust, with petroleum potential implications
Authors: Artyushkov E.V.
Published: December 2009

The large North Chukchi Basin in the northeastern Eurasian shelf is filled with up to 22 km of sediments, which is far thicker than filling a basin upon oceanic crust would require. The basin sedimentation began 380 Myr ago, and about 16 km of sediments have been deposited for the past 125 Myr, long after the oceanic crust would have completed its subsidence. This fact is in favor of the continental instead of oceanic crust origin. Rapid basin subsidence appears to be driven by a mechanism other than crustal stretching as the latter has no evidence over the greatest part of the basin area. The suggested basin formation model implies a transformation of gabbro into denser eclogite in the lower crust and related contraction of mafic rocks. To sustain consolidated crust beneath 22 km thick sediments, the layer of dense eclogites under the granitic layer must be at least ∼25 km thick. The presence of basement flexures formed at several stages of the basin evolution indicates a considerable loss of lithospheric rigidity under the effect of fluid infiltration from small mantle plumes. The fluids catalyzed the eclogitization and thus increased the subsidence rate. Rapid subsidence apparently occurred in Barremian-Albian time when the basin had accumulated up to 11.5 km of sediments. Besides the Early Cretaceous event, there were, possibly several older events of rapid subsidence. This basin subsidence history, along with the evidence of steep lithospheric flexure, is a known feature of large petroleum basins. Therefore, the North Chukchi Basin may be expected to be an oil and gas producer.
The Svalbard–Kara plates junction: structure and geodynamic history
Authors: Shipilov E.V. , Vernikovsky V.A.
Published: December 2009

The structure and geodynamic history of the northern Barents–Kara continental margin, which had formed mostly by the latest Paleozoic, have been investigated using offshore geological and geophysical data and geological evidence from adjacent landmasses. In the context of the suggested model, the Saint Anna trough is interpreted as a boundary tectonic element between the Svalbard and Kara plates. Thus, the study focuses on a complex tectonic node with its structure having implications for the trough origin, as well as for the history of geodynamic relations among Arctic cratons and microplates. Trough structures of different ages in the area, including the northeastern East Barents trough and the St. Anna trough, appear to be a zone of triple or T-shaped junction. The reported reconstruction of the trough system history since the Middle Paleozoic shows that the St. Anna trough joined the East-Barents system in the Late Permian–Triassic to become its new segment extending the system to the north.
Formation of gas hydrate deposits in the Siberian Arctic shelf
Authors: Safronov A.F. , Shits E.Yu. , Grigor’ev M.N. , Semenov M.E.
Published: December 2009

Natural gas hydrate deposits have been estimated to store about 10% of gas in hydrate form (even with regard to a higher concentration of gas in hydrates), proceeding from the known ratio of dissolved-to-deposited gas. This high percentage is largely due to the fact that the buffer factor in natural gas hydrate deposits is lower than that for free gas because of less diverse structural conditions for gas accumulation. Therefore, the available appraisal of world resources of hydrated gas needs a revision.

Hydrates in rocks are either syngenetic or epigenetic. Syngenetic hydrates originate from free or dissolved gas which was present in rocks in situ at the time when PT-conditions became favorable for gas hydrate formation. Epigenetic hydrates are derived from gas which came by migration into rocks with their PT-conditions corresponding to formation of gas hydrates.

In addition to the optimum PT-conditions and water salinity, economic gas hydrate accumulation requires sustained supply of natural gas into a specific zone of gas hydrate formation. This condition is feasible only in the case of vertical migration of natural gas along faults, fractured zones, and lithologic windows, or, less often, as a result of lateral migration.

Of practical importance are only the gas hydrate deposits produced by vertical or lateral gas migration.
Natural bitumen fields in the northeast of the Siberian Platform (Russian Arctic sector)
Authors: Kashirtsev V.A. , Kontorovich A.E. , Ivanov V.L. , Safronov A.F.
Published: December 2009

In the northern and northeastern Siberian Platform, within the Anabar and Olenek zones, there are a number of hypergene bitumen accumulations (fields) and natural bitumen seeps, whose total resources are estimated at >5 bln tons. Bitumen fields are confined to a wide stratigraphic range from Precambrian to Mesozoic. A detailed geochemical study was performed for bitumens of the largest Olenek field, whose naphthides are localized mainly in Permian sandstones of deltaic and coast-marine genesis. Chromato-mass spectrometric analysis showed that normal alkanes are drastically reduced in the saturated fraction of the bitumens and most of terpanes are a homologous series of 25-norhopanes, which evidences the intense bacterial degradation of hydrocarbon pools. Identification of bicyclic sesquiterpenes, tetracyclic onocerane, and other biomarkers testifies that the organic matter of source rocks was rich in higher-plants remains. The concentrations of steranes are low, whereas those of earlier unknown 8-14-secosteranes are rather high. The set of geochemical data on the Permian bitumens of the Olenek field, including the isotopic characteristics of carbon (δ13C of −25.8 to −31.3‰), suggests that the coeval oil source rocks on the passive continental margin (at the place of the present-day Verkhoyansk fold belt) were the main source of hydrocarbons for the field. Assessment of oil and gas resources, including giant bitumen pools, and their exploration in the framework of “The fundamentals of Russian state policy in Arctic up to 2020” have become a top-priority problem. Petroleum refining products might be economically feasible raw materials in the eastern Russian Arctic sector to be supplied via the Northern Sea Route.
Geochemistry of organic matter of bottom sediments in the rises of the central Arctic Ocean
Authors: Petrova V.I. , Batova G.I. , Kursheva A.V. , Litvinenko I.V.
Published: December 2009

Based on geomorphological, lithological, and facial characteristics of the East Arctic continental margin, we studied the main factors controlling the Late Cenozoic supply of organic matter (OM) to the bottom sediments of the Central Arctic rises of the Arctic Ocean. Complex analysis of dispersed OM in the samples taken during the expeditions of the R/V “Akademik Fedorov” in 2000 and 2005 showed a significant difference between the sediments of the Lomonosov Ridge and Mendeleev Rise. The bottom sediments of the latter are strongly transformed and lack terrigenous components, as evidenced results from the main geochemical characteristics (contents of Corg, Ccarb, Norg, bitumens, and humic acids) and the composition and distribution of hydrocarbon molecular markers (alkanes, saturated and aromatic cyclanes). The obtained data evidence that ancient sedimentary rocks containing genetically uniform deeply transformed (up to mesocatagenesis) OM played a significant role in the formation of the Pleistocene–Holocene sediments of the axial part of the Mendeleev Rise.
Shelf placer deposits: a new technology for winter mining
Authors: Kislyakov V.E. , Korzun O.A. , Lakin D.A.
Published: December 2009

The paper concerns urgent problems of resources development in the Arctic shelf. A specially designed technology with the use of a coolant is suggested for winter mining at shelf deposits. The idea of the new technology stems from the concept of negative settling velocity of buoyant particles which has been investigated in laboratory tests.
Kimberlites of the Manchary pipe: a new kimberlite field in Central Yakutia
Authors: Smelov A.P. , Andreev A.P. , Altukhova Z.A. , Babushkina S.A. , Bekrenev K.A. , Zaitsev A.I. , Izbekov E.D. , Koroleva O.V. , Mishnin V.M. , Okrugin A.V. , Oleinikov O.B. , Surnin A.A.
Published: December 2009

This paper reports new petrographic and mineralogical data on the Manchary kimberlite pipe, which was discovered south of Yakutsk (Central Yakutia) in 2007–2008, 100 km. The pipe breaks through the Upper Cambrian carbonate deposits and is overlain by Jurassic terrigenous rock masses about 100 m thick. It is composed of greenish-gray kimberlite breccia with a serpentine-micaceous cement of massive structure. The porphyry texture of kimberlite is due to the presence of olivine, phlogopite, and picroilmenite phenocrysts. The SiO2 and Al2O3 contents of the groundmass are indicative of typical noncontaminated kimberlites. The groundmass has a significant content of ore minerals: Fe- and Cr-spinels, perovskite, magnetite, and, less commonly, magnesian Cr-magnetite. Pyropes occur in kimberlites as sharp-edged fragments and show uneven distribution. Chemically, they belong to lherzolite, wehrlite, or nondiamondiferous dunite–harzburgite parageneses. Garnets corresponding to lherzolites of anomalous composition make up 8%; this is close to the garnet content of Middle Paleozoic kimberlites from the Yakutian kimberlite province. The pyropes from the new pipe are compositionally similar to those from diamond-poor Middle Paleozoic kimberlites in the north of the Yakutian diamondiferous province. Chemically, pyropes from the Manchary pipe and those from the modern alluvium of the Kengkeme and Chakyya Rivers differ substantially. Consequently, the rocks of the pipe could not be a source of pyropes for this alluvium. They probably occured from other sources. This fact along with numerous “pipelike” geophysical anomalies, suggest the existence of a new kimberlite field in Central Yakutia.
Mineral potential of the Russian Arctic: state and efficient development
Authors: Safonov Yu.G.
Published: December 2009

The metallogeny of the Russian Arctic zone, with a high potential for U, platinum-group metals, Au, Sn, trace elements, etc., in its different sectors, has been controlled by the type of early continental structures and by the uniform Meso-Cenozoic evolution of the area. The suggested reasonable development strategy is to conserve and further develop the existing mining districts associated with known large fields and to discover new primary (U, Au, etc.) and placer deposits. It is important to provide scientific background and environmental monitoring in the area at the stages of mineral prediction, exploration, and development.
Anthropogenic perturbations of the silicon cycle at the global scale: Key role of the land‐ocean transition
Authors: Laruelle G. G. , Roubeix V. , Sferratore A. , Brodherr B. , Ciuffa D. , Conley D. J. , Dürr H. H. , Garnier J. , Lancelot C. , Le Thi Phuong Q. , Meunier J.‐D. , Meybeck M. , Michalopoulos P. , Moriceau B. , Ní Longphuirt S. , Loucaides S. , Papush L. , Presti M. , Ragueneau O. , Regnier P. , Saccone L. , Slomp C. P. , Spiteri C. , Van Cappellen P.
Published: December 2009

Silicon (Si), in the form of dissolved silicate (DSi), is a key nutrient in marine and continental ecosystems. DSi is taken up by organisms to produce structural elements (e.g., shells and phytoliths) composed of amorphous biogenic silica (bSiO2). A global mass balance model of the biologically active part of the modern Si cycle is derived on the basis of a systematic review of existing data regarding terrestrial and oceanic production fluxes, reservoir sizes, and residence times for DSi and bSiO2. The model demonstrates the high sensitivity of biogeochemical Si cycling in the coastal zone to anthropogenic pressures, such as river damming and global temperature rise. As a result, further significant changes in the production and recycling of bSiO2 in the coastal zone are to be expected over the course of this century.
Is summer monsoon rainfall decreasing over India in the global warming era?
Authors: Naidu C. V. , Durgalakshmi K. , Muni Krishna K. , Ramalingeswara Rao S. , Satyanarayana G. C. , Lakshminarayana P. , Malleswara Rao L.
Published: December 2009

Using long‐term (1871–2005) summer monsoon rainfall data over 30 meteorological subdivisions of India, overall tendencies of the rainfall have been studied. Further, the subseasonal (monthly) trends have been evaluated. For this purpose, simple linear regression technique is applied. To examine the trends in different segments for summer monsoon rainfall, 11‐year running averages are calculated. Most of the subdivisions reveal systematic increasing and decreasing trends in different segments of the time series. India experienced wet monsoon conditions during the late 1950s and dry monsoon conditions around the early 1900s. In the global warming era (1970–2005), 19 out of 30 meteorological subdivisions showed negative tendencies in summer monsoon rainfall. This decrease in summer monsoon rainfall is associated with a weakening of the Southern Oscillation and relaxation of the meridional temperature gradient over the Indian Ocean. The gamma distribution is used to study the distribution of the rainfall by calculating scale and shape parameters. In general, larger values of scale parameter are found over west coast during summer monsoon and individual months. The shape parameter is high over northeast India.
Solar UV‐B and UV‐A irradiance in arid high‐mountain regions: Measurements on the island of Tenerife as compared to previous tropical Andes data
Authors: Piazena H. , Häder D.‐P.
Published: December 2009

Spectroradiometric measurements of global and diffuse solar UV‐B and UV‐A irradiance were performed as a function of solar elevation under clear‐sky conditions at altitudes between sea level and the top of the volcano El Teide (3555 m above sea level (asl)) at the arid part of the island of Tenerife (Spain) and compared with irradiance data previously measured in the tropical Chilean Andes. Total optical depths and their components were calculated by using data of direct solar irradiance determined in dependence of the solar elevation angle and of altitude. The Ratio total/Rayleigh optical depth increased with altitude in the short‐wavelength UV range and decreased with altitude for long‐wavelength UV radiation. Rayleigh scattering contributed dominantly to the attenuation of irradiance for both UV‐A and for wavelengths between 308 nm and 319 nm in the total range of altitudes investigated as compared with the contributions of ozone absorption and of aerosol absorption and scattering. The latter effects were more effective for the attenuation of solar irradiance in the spectral range of UV‐B for altitudes above about 500–960 m asl as compared with the effect of Rayleigh scattering. Increases of global irradiance with increasing altitude were mainly caused by an increase of the direct component in both spectral ranges. Because of the attenuation of direct solar irradiance during its transmittance through vertically stratified near‐surface layers characterized by increased values of the aerosol optical depth, vertical gradients of global irradiance and of its direct component observed at Tenerife in the lower part of the investigated atmospheric layer exceeded in both spectral ranges the gradients determined in the upper part in the case of small solar elevation angles. Similarity with the vertical gradients of global irradiance in the Andes was observed in the case of solar elevation angles above about 40° for both UV‐A and UV‐B within the upper layer and above about 60° for both layers and for both spectral ranges whereas the gradients observed in both layers at Tenerife covered the gradients derived in the Andes for smaller solar elevation angles.
Effects of Typhoon Kaemi on coastal phytoplankton assemblages in the South China Sea, with special reference to the effects of solar UV radiation
Authors: Li Gang , Wu Yaping , Gao Kunshan
Published: December 2009

In order to see how physical and chemical changes in coastal environment caused by tropical cyclones would affect primary productivity of phytoplankton, we investigated the photosynthetic carbon fixation, the chlorophyll a concentration, and the species composition of phytoplankton assemblages in the surface coastal waters of the South China Sea, during 18 July to 7 August 2006, before and after Typhoon Kaemi's landing (on 25 July, 122 km away from the experimental site). Chlorophyll a concentration started to decrease from 12.3 μg L−1 30 h before to 1.5 μg L−1 40 h after its landing, reducing the capacity of photosynthetic carbon fixation in the seawater to one eighth. Prior to the typhoon's arrival, microplankton (>20 μm) accounted for 50% of the total chl a, being mainly dominated by the diatom Thalassiosira sp.; during the period 30 h before and 6 days after the typhoon, however, pico‐nanoplankton (<20 μm) comprised 98% of the total chl a. By 2 weeks after the typhoon, microcells (>20 μm) dominated the species again, and occupied 60% of the total chl a, with the diatom Nitzschia sp. being the dominant group. Since the typhoon induced changes in taxonomic structure and environmental factors, the apparent photosynthetic efficiency (α) of phytoplankton assemblages was markedly enhanced after the typhoon, while both the light‐saturating point (Ek) and noontime photosynthetic rates were significantly reduced. Solar ultraviolet radiation (UVR, >55 W m−2) significantly inhibited the photosynthetic carbon fixation by 17% and 28% before and after the typhoon, respectively, reflecting a higher UVR sensitivity of the posttyphoon phytoplankton assemblages.
A New Approach to Data Publication in Ocean Sciences
Authors: Lowry Roy , Urban Ed , Pissierssens Peter
Published: December 2009

Data are collected from ocean sciences activities that range from a single investigator working in a laboratory to large teams of scientists cooperating on big, multinational, global ocean research projects. What these activities have in common is that all result in data, some of which are used as the basis for publications in peer‐reviewed journals.

However, two major problems regarding data remain. First, many data valuable for understanding ocean physics, chemistry, geology, biology, and how the oceans operate in the Earth system are never archived or made accessible to other scientists. Data underlying traditional journal articles are often difficult to obtain. Second, when scientists do contribute data to databases, their data become freely available, with little acknowledgment and no contribution to their career advancement. To address these problems, stronger ties must be made between data repositories and academic journals, and a “digital backbone” needs to be created for data related to journal publications.
Biogeochemical iron budgets of the Southern Ocean south of Australia: Decoupling of iron and nutrient cycles in the subantarctic zone by the summertime supply
Authors: Bowie Andrew R. , Lannuzel Delphine , Remenyi Tomas A. , Wagener Thibaut , Lam Phoebe J. , Boyd Philip W. , Guieu Cécile , Townsend Ashley T. , Trull Thomas W.
Published: December 2009

Climate change is projected to significantly alter the delivery (stratification, boundary currents, aridification of landmasses, glacial melt) of iron to the Southern Ocean. We report the most comprehensive suite of biogeochemical iron budgets to date for three contrasting sites in subantarctic and polar frontal waters south of Australia. Distinct regional environments were responsible for differences in the mode and strength of iron supply mechanisms, with higher iron stocks and fluxes observed in surface northern subantarctic waters, where atmospheric iron fluxes were greater. Subsurface waters southeast of Tasmania were also enriched with particulate iron, manganese and aluminum, indicative of a strong advective source from shelf sediments. Subantarctic phytoplankton blooms are thus driven by both seasonal iron supply from southward advection of subtropical waters and by wind‐blown dust deposition, resulting in a strong decoupling of iron and nutrient cycles. We discuss the broader global significance our iron budgets for other ocean regions sensitive to climate‐driven changes in iron supply.
Mesozoic history of the Fairway‐Aotea Basin: Implications for the early stages of Gondwana fragmentation
Authors: Collot J. , Herzer R. , Lafoy Y. , Géli L.
Published: December 2009

The Fairway Ridge is a buried continental structure that separates the Fairway Basin from the New Caledonia Basin. The proposed Cretaceous age of the Fairway Basin has remained highly hypothetical to date. Deep offshore petroleum exploration wells revealed well‐dated Mesozoic carbonaceous sedimentary rocks in the Taranaki Basin at the southern end of the Aotea Basin. In this paper we use geophysical data to confirm the continuity of the 2000 km long Fairway‐Aotea Basin connecting New Caledonia to New Zealand and prove its early Late Cretaceous age. Analysis of seismic reflection profiles together with newly compiled gravity and magnetic maps reveals Late Cretaceous NE–SW trending lineaments projecting northeastward from major Tasman Sea fracture zones and the Bellona Trough, which demonstrate that the opening of the Fairway‐Aotea Basin predates the opening of the Tasman Sea. This result combined with observations of the Mesozoic regional geology suggests that the Lord Howe, Fairway, and Norfolk ridges are part of a remnant late Early Cretaceous continental arc, which was fragmented into three pieces by the late Early to early Late Cretaceous. This event might be contemporaneous with a plate motion change between the Gondwana and Pacific plates and/or the arrival of the Hikurangi plateau in the subduction zone around 105 Ma, which caused the cessation of subduction along this plate boundary. We interpret either of those two events as being possible trigger events for the post–Early Cretaceous fragmentation of the eastern Gondwana margin in a slab retreat process.
Coral proxy record of decadal‐scale reduction in base flow from Moloka'i, Hawaii
Authors: Prouty Nancy G. , Jupiter Stacy D. , Field Michael E. , McCulloch Malcolm T.
Published: December 2009

Groundwater is a major resource in Hawaii and is the principal source of water for municipal, agricultural, and industrial use. With a growing population, a long‐term downward trend in rainfall, and the need for proper groundwater management, a better understanding of the hydroclimatological system is essential. Proxy records from corals can supplement long‐term observational networks, offering an accessible source of hydrologic and climate information. To develop a qualitative proxy for historic groundwater discharge to coastal waters, a suite of rare earth elements and yttrium (REYs) were analyzed from coral cores collected along the south shore of Moloka'i, Hawaii. The coral REY to calcium (Ca) ratios were evaluated against hydrological parameters, yielding the strongest relationship to base flow. Dissolution of REYs from labradorite and olivine in the basaltic rock aquifers is likely the primary source of coastal ocean REYs. There was a statistically significant downward trend (−40%) in subannually resolved REY/Ca ratios over the last century. This is consistent with long‐term records of stream discharge from Moloka'i, which imply a downward trend in base flow since 1913. A decrease in base flow is observed statewide, consistent with the long‐term downward trend in annual rainfall over much of the state. With greater demands on freshwater resources, it is appropriate for withdrawal scenarios to consider long‐term trends and short‐term climate variability. It is possible that coral paleohydrological records can be used to conduct model‐data comparisons in groundwater flow models used to simulate changes in groundwater level and coastal discharge.
A novel method for determination of aragonite saturation state on the continental shelf of central Oregon using multi‐parameter relationships with hydrographic data
Authors: Juranek L. W. , Feely R. A. , Peterson W. T. , Alin S. R. , Hales B. , Lee K. , Sabine C. L. , Peterson J.
Published: December 2009

We developed a multiple linear regression model to robustly determine aragonite saturation state (Ωarag) from observations of temperature and oxygen (R2 = 0.987, RMS error 0.053), using data collected in the Pacific Northwest region in late May 2007. The seasonal evolution of Ωarag near central Oregon was evaluated by applying the regression model to a monthly (winter)/bi‐weekly (summer) water‐column hydrographic time‐series collected over the shelf and slope in 2007. The Ωarag predicted by the regression model was less than 1, the thermodynamic calcification/dissolution threshold, over shelf/slope bottom waters throughout the entire 2007 upwelling season (May–November), with the Ωarag = 1 horizon shoaling to 30 m by late summer. The persistence of water with Ωarag < 1 on the continental shelf has not been previously noted and could have notable ecological consequences for benthic and pelagic calcifying organisms such as mussels, oysters, abalone, echinoderms, and pteropods.
Cycling of DDT in the global environment 1950–2002: World ocean returns the pollutant
Authors: Stemmler Irene , Lammel Gerhard
Published: December 2009

The global distribution and fate of the insecticide DDT was modeled for the first time using a spatially resolved global multicompartment chemistry‐transport model comprising a 3D coupled atmosphere and ocean GCM, coupled to 2D vegetation surfaces and top soils. DDT enters the model environment as a pesticide in agriculture only. Final sinks of DDT in the total environment are degradation in air (hydroxyl radical reaction), on vegetation surfaces, in ocean sediments and soils. The process resolution of the ocean compartment, i.e., either a fixed or variable size and sinking velocity of suspended particles, has almost no effect on the large‐scale cycling and fate of DDT. The residence times in various ocean basins were declining but varied regionally. The global ocean absorbed until 1977 and since then has been losing DDT, while large sea areas are still accumulating the pollutant. The main sink is volatilization to the atmosphere. In 1990, the year when emissions ceased, 292 kt of DDT were deposited to the global ocean, 301 kt were volatilized, and 41 kt were exported from the surface layer to the deeper levels. The sea region that has been representing the most significant (secondary) DDT source is the western N Atlantic (Gulf stream and N Atlantic Drift regions). It has been a source since approximately 1970. Also large parts of the tropical ocean and the southern mid‐latitude ocean have turned net volatilizational (i.e., volatilization flux > deposition flux) during the 1980s. Despite the emissions migrating southward as a consequence of substance ban in mid latitudes, the geographic distribution of the contaminant (and, hence, environmental exposure) has been migrating steadily northward since the 1960s.
Self‐focused radio frequency L wave pumping of localized upper hybrid oscillations in high‐latitude ionospheric plasma
Authors: Leyser T. B. , Nordblad E.
Published: December 2009

In experiments on radio frequency pumping of ionospheric plasma it is usually assumed that the pump wave propagates in the ordinary (O) mode. However, it is shown by ray tracing that commonly excited filamentary density inhomogeneities will guide a transmitted O‐mode pump wave along the geomagnetic field as an L wave. Nonlinearly guided L‐wave pumping of long predicted localized upper hybrid oscillations offers a unified understanding of a range of experimental results, including strong self‐focusing for pump beams near geomagnetic zenith.