bluuebunny/crossref_metadata_2025 huggingface dataset:
ChemInform Abstract: Synthesis of Novel Anilinoquinolines as c‐fms Inhibitors.
Authors: Smalley Terrence L. Jr. , Chamberlain Stanley D. , Mills Wendy Y. , Musso David L. , Randhawa Sab A. , Ray John A. , Samano Vicente , Frick Lloyd
Published: February 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Synthesis of 1‐[2‐(1,3‐Benzoxazol‐2‐yl)‐2‐oxoethylidene] ‐3,3‐dimethyl‐1,2,3,4‐tetrahydroisoquinoline Derivatives (III).
Authors: Surikova O. V. , Mikhailovskii A. G. , Polygalova N. N. , Neifel'd P. G. , Vakhrin M. I.
Published: February 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Studies on Quinazoline Chemistry. Part 4. Unexpected Route of Acylation of Alkyl 2‐(4,4‐Diphenyl‐1,2,3,4‐tetrahydro‐2‐quinazolinylidene)acetates. Molecular Structure of Methyl 2‐(4,4‐Diphenyl‐1,2,3,4‐tetrahydro‐2‐quinazolinylidene)‐3‐oxobutanoate.
Authors: Gromachevskaya E. V. , Kaigorodova E. A. , Zavodnik V. E. , Krapivin G. D.
Published: February 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Condensed Isoquinolines. Part 22. Synthesis and Properties of 6,11‐Dihydro‐13H‐isoquino[3,2‐b]quinazolin‐13‐ones.
Authors: Potikha L. M.
Published: February 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Regioselective Synthesis of Asymmetrically Substituted 2‐Quinoxalinol Salen Ligands.
Authors: Wu Xianghong , Gorden Anne E. V. , Tonks Stephen A. , Vilseck Jonah Z.
Published: February 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Part 6. Synthesis of Spiro 1,5‐Benzodiazepine Attached with Different Heterocyclic Moieties.
Authors: Khodairy A. , El‐Sayed A. M. , Salah H. , Abdel‐Ghany H.
Published: February 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Synthesis of Novel Well‐Defined Chain‐End‐Functionalized Polystyrene with Dentritic Chiral Ephedrine Moieties and Their Applications as Highly Enantioselective Diethylzinc Addition to N‐Diphenylphosphinoyl Arylimines.
Authors: El‐Shehawy Ashraf A.
Published: February 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Synthesis of Ethyl 4‐O‐[4‐(1,2,4‐Oxadiazol‐5‐yl)phenyl]‐α‐D‐mannopyranosides.
Authors: dos Anjos Janaina Versiani , Sinou Denis , de Melo Sebastiao Jose , Srivastava Rajendra Mohan
Published: February 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Synthesis of Semicyclic Dienes by Modified Julia Olefination of Vinyl Sulfones Derived from Carbohydrates.
Authors: Aouadi Kaiss , Defaut Benedicte , Goekjian Peter G. , Gueyrard David
Published: February 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Investigation of the Acid‐Catalyzed Rearrangement of Morphinans.
Authors: Csutoras Csaba , Berenyi Sandor , Neumeyer John L.
Published: February 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Asymmetric Total Syntheses of Two Phlegmarine‐Type Alkaloids, Lycoposerramines‐V and ‐W, Newly Isolated from Lycopodium serratum.
Authors: Shigeyama Takahide , Katakawa Kazuaki , Kogure Noriyuki , Kitajima Mariko , Takayama Hiromitsu
Published: February 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Isatisine A (Ia), a Novel Alkaloid with an Unpresedented Skeleton from Leaves of Isatis indigotica.
Authors: Liu Ji‐Feng , Jiang Zhi‐Yong , Wang Rui‐Rui , Zheng Yong‐Tang , Chen Ji‐Jun , Zhang Xue‐Mei , Ma Yun‐Bao
Published: February 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Synthesis and Evaluation of Substituted Benzoisoquinolinones as Potent Inhibitors of Chk1 Kinase.
Authors: Garbaccio Robert M. , et al. et al.
Published: February 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: N‐Alkylidenearylcarboxamides as New Potent and Selective CB2 Cannabinoid Receptor Agonists with Good Oral Bioavailability.
Authors: Ohta Hiroshi , Ishizaka Tomoko , Tatsuzuki Makoto , Yoshinaga Mitsukane , Iida Izumi , Tomishima Yasumitsu , Toda Yoshihisa , Saito Shuji
Published: February 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Asymmetric Catalytic Redox System: Tethered Bis(8‐quinolinolato) (TBOx) Chromium(III)/(II) Complexes
Authors: Yamamoto Hisashi , Xia Guoyao
Published: February 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Recent Advances on the Synthesis and Chemistry of Carbaporphyrins and Related Porphyrinoid Systems
Authors: Lash Timothy D.
Published: February 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Catalytic Enantioselective Stereoablative Reactions: An Unexploited Approach to Enantioselective Catalysis
Authors: Mohr Justin T. , Ebner David C. , Stoltz Brian M.
Published: February 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Click Chemistry as a High‐Throughput Amenable Platform in Catalomics
Authors: Kalesh Karunakaran Anandamma , Yang Peng‐Yu , Srinivasan Rajavel , Yao Shao Qin
Published: February 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Molecules that Target β‐Amyloid
Authors: Stains Cliff I. , Mondal Kalyani , Ghosh Indraneel
Published: February 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: IUPAC‐NIST Solubility Data Series. Part 82. Alcohols with Water‐Revised and Updated: Part 5. C8—C17 Alcohols with Water
Authors: Maczynski Andrzej , Shaw David G. , Goral Marian , Wisniewska‐Goclowska Barbara
Published: February 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Models for the Hydrogenases Put the Focus Where It Should Be — Hydrogen
Authors: Mealli Carlo , Rauchfuss Thomas B.
Published: February 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Combinatorial Enzymatic Synthesis of Heparan Sulfate
Authors: Linhardt Robert J. , Kim Jin‐Hwan
Published: February 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Mild gestational hyperglycaemia as a risk factor for metabolic syndrome in pregnancy and adverse perinatal outcomes
Authors: Negrato Carlos Antonio , Jovanovic Lois , Tambascia Marcos Antonio , Calderon Iracema de Mattos Paranhos , Geloneze Bruno , Dias Adriano , Rudge Marilza Vieira Cunha
Published: February 2008

Objective

The aims of this study were to evaluate the prevalence of metabolic syndrome (MS) in a cohort of pregnant women with a wide range of glucose tolerance, pre‐pregnancy risk factors for MS during pregnancy and the effects of MS in the occurrence of adverse perinatal outcomes.

Research Design and Methods

One hundred and thirty six women with positive screening for gestational diabetes (GDM) were classified by two diagnostic methods: glycaemic profile and 100 g oral glucose tolerance test (OGTT) as normoglycaemic, mild gestational hyperglycaemic, GDM, and overt GDM. Markers of insulin resistance were measured between 24–28 and 36th week of gestation, and 6 weeks after delivery.

Results

The prevalence of MS was 0; 20.0; 23.5 and 36.4% in normoglycaemic, mild hyperglycaemic, GDM and overt GDM groups, respectively. Previous history of GDM with or without insulin use, body mass index (BMI) ≥ 25, hypertension, family history of diabetes in first‐degree relatives, non‐Caucasian ethnicity, history of prematurity and polyhydramnios were statistically significant pre‐pregnancy predictors for MS in the index pregnancy, that by its turn increased the occurrence of adverse perinatal outcomes (p = 0.01).

Conclusions

The prevalence of MS increases with the worsening of glucose tolerance and is an independent predictor of adverse perinatal outcomes; impaired glycaemic profile identifies pregnancies with important metabolic abnormalities that are linked to the occurrence of adverse perinatal outcomes even in the presence of a normal OGTT, in patients that are not currently classified as having GDM. Copyright © 2008 John Wiley & Sons, Ltd.
Efficient, inducible Cre‐recombinase activation in vascular endothelium
Authors: Claxton Suzanne , Kostourou Vassiliki , Jadeja Shalini , Chambon Pierre , Hodivala‐Dilke Kairbaan , Fruttiger Marcus
Published: February 2008

In recent years, gene‐targeting studies in mice have elucidated many molecular mechanisms in vascular biology. However, it has been difficult to apply this approach to the study of postnatal animals because mutations affecting the vasculature are often embryonically lethal. We have therefore generated transgenic mice that express a tamoxifen‐inducible form of Cre recombinase (iCreERT2) in vascular endothelial cells using a phage artificial chromosome (PAC) containing the Pdgfb gene (Pdgfb‐iCreER mice). This allows the genetic targeting of the vascular endothelium in postnatal animals. We tested efficiency of tamoxifen‐induced iCre recombinase activity with ROSA26‐lacZ reporter mice and found that in newborn animals recombination could be achieved in most capillary and small vessel endothelial cells in most organs including the central nervous system. In adult animals, recombination activity was also widespread in capillary beds of skeletal muscle, heart, skin, and gut but not in the central nervous system where only a subpopulation of endothelial cells was labeled. We also tested recombination efficiency in a subcutaneous tumor model and found recombination activity in all detectable tumor blood vessels. Thus, Pdgfb‐iCreER mice are a valuable research tool to manipulate endothelial cells in postnatal mice and study tumor angiogenesis. genesis 46:74–80, 2008. © 2008 Wiley‐Liss, Inc.
Induction of apoptosis by Drosophila Myc
Authors: Montero Lilian , Müller Nadine , Gallant Peter
Published: February 2008

Myc proteins are essential regulators of cellular growth and proliferation during normal development. Activating mutations in myc genes result in excessive growth and are frequently associated with human cancers. At the same time, forced expression of Myc sensitizes vertebrate cells towards different pro‐apoptotic stimuli. Recently, the ability of overexpressed Myc to induce cell‐autonomous apoptosis has been shown to be evolutionarily conserved in Drosophila Myc (dMyc). Here, we show that dMyc induced apoptosis is accompanied by the induction of Drosophila p53 mRNA, but that dp53 activity is not essential for dMyc's ability to induce apoptosis. Conversely, larvae carrying a hypomorphic dmyc mutation are more resistant to the apoptosis‐promoting effects of X‐irradiation. These data suggest that the control of apoptosis is a physiological function of Myc and that dMyc might play a role in the response to DNA damage. genesis 46:104–111, 2008. © 2008 Wiley‐Liss, Inc.
The hexachiral prismatic wingbox concept
Authors: Martin Jamie , Heyder‐Bruckner Jean‐Jacques , Remillat Chrystel , Scarpa Fabrizio , Potter Kevin , Ruzzene Massimo
Published: February 2008

In this work the concept of using a chiral honeycomb as the internal structure for a passively morphing wing is explored. The use of a chiral honeycomb, which features an in‐plane negative Poisson's ratio, potentially offers high deformability whilst maintaining structural integrity of the wing box. A finite element simulation was carried out, coupling a complete two‐dimensional model of the wing and internal structure to a panel code flow solver. An iterative process was then used in order to predict the wing camber change with respect to airflow. The concept was validated experimentally through the construction of a prototype wing for wind‐tunnel testing. The measured response was non‐linear with respect to aerodynamic loading, but the final deflected shape at the design case compared well with the finite element prediction. The concept was proven to work for small camber changes, with larger deflections predicted by tailoring the mechanical properties of the hexachiral core. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The influence of the water surrounding on a long‐distance electron transport in the DNA
Authors: Matulewski J. , Orłowski S. , Baranovskii S. D. , Thomas P.
Published: February 2008

Results of the molecular dynamics simulations of the DNA double helix structure suggest that the additional low frequency oscillations appear if water surrounding is present as compared to the case of dry DNA. The effect of these oscillations on electron transport along the DNA is studied using a comprehensive quantum‐mechanical coherent approach in the framework of a one‐dimensional Kronig‐Penney model. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Vibrational excitations in systems with correlated disorder
Authors: Schirmacher W. , Schmid B. , Tomaras C. , Viliani G. , Baldi G. , Ruocco G. , Scopigno T.
Published: February 2008

We investigate a d ‐dimensional model (d = 2,3) for sound waves in a disordered environment, in which the local fluctuations of the elastic modulus are spatially correlated with a certain correlation length. The model is solved analytically by means of a field‐theoretical effective‐medium theory (self‐consistent Born approximation) and numerically on a square lattice. As in the uncorrelated case the theory predicts an enhancement of the density of states over Debye's ωd –1 law (“boson peak”) as a result of disorder. This anomay becomes reinforced for increasing correlation length ξ.

The theory predicts that ξ times the width of the Brillouin line should be a universal function of ξ times the wavenumber. Such a scaling is found in the 2d simulation data, so that they can be represented in a universal plot. In the low‐wavenumber regime, where the lattice structure is irrelevant there is excellent agreement between the simulation at small disorder. At larger disorder the continuum theory deviates from the lattice simulation data. It is argued that this is due to an instability of the model with stronger disorder. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Nanostructured antiferromagnetic spin glass in doped Ge near the insulator–metal transition
Authors: Zabrodskii A. G. , Veinger A. I. , Tisnek T. V. , Goloshchapov S. I.
Published: February 2008

It is shown that, on the insulator side of the insulator – metal transition, the single spin density exponentially disappears as T → 0. Such spins are bound into pairs to give an antiferromagnetic (AFM) phase. Upon an increase in temperature the AFM phase is destroyed, the single‐spin density, and, as a result, ESR absorption signal becomes stronger. The temperature dependencies of the densities of the pairs and single spins are typical of a chaotic distribution of neutral donors. In this case, there is no Neel temperature. In low degree of compensation, the crystal lattice of Ge with the AFM phase is actually a nanostructured system characterized by anisotropic internal stresses that are the strongest along one of the [110] directions. These stresses give rise to anisotropy of the g‐factor which is responsible for experimentally observed splitting of the ESR line. The compensating impurities destroy the AFM phase and reduce this splitting. Local stresses are present in this case, too, but now they appear because of the Coulomb interaction of oppositely charged impurities and have no preferred orientation. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Identification of Lysophosphatidylcholine–Chlorohydrin in Human Atherosclerotic Lesions
Authors: Messner M. C. , Albert C. J. , McHowat J. , Ford D. A.
Published: February 2008

Lysophosphatidylcholine (LysoPtdCho) levels are elevated in sera in patients with atherosclerosis and in atherosclerotic tissue. Previous studies have shown that reactive chlorinating species attack plasmalogens in human coronary artery endothelial cells (HCAEC), forming lysoPtdCho and lysoPtdCho–chlorohydrin (lysoPtdCho–ClOH). The results herein demonstrate for the first time that lysoPtdCho–ClOH is elevated over 60‐fold in human atherosclerotic lesions. In cultured HCAEC, 18:0 lysoPtdCho–ClOH led to a statistically significant increase in P‐selectin cell‐surface expression, but unlike 18:1 lysoPtdCho did not lead to cyclooxygenase‐2 protein expression. These data show that 18:0 lysoPtdCho–ClOH is elevated in atherosclerotic tissue and may have unique pro‐atherogenic properties compared to lysoPtdCho.
Turbulence‐induced forces in a freshwater macrophyte canopy
Authors: Plew David R. , Cooper Glenn G. , Callaghan Fraser M.
Published: February 2008

Drag forces on macrophytes in a steady turbulent flow consist of both a mean and fluctuating component. Macrophytes that form a canopy experience lower mean forces due to a reduction of velocities within the canopy. However, submerged canopies also generate additional turbulence. In this study, an experiment is conducted in a laboratory flume to investigate how canopy density influences both mean and unsteady forces on a macrophyte. Canopies with densities of 39, 156, and 625 stems m−2 are constructed from 25 cm lengths of Lagarosiphon major. Drag is measured on a single stem within the canopy at four flow rates. The results show that although mean forces are reduced with increasing canopy density, the unsteady force (characterized by RMS of fluctuations from the mean) increases with the square‐root of canopy density. The force response of the stem to the turbulence was frequency dependent with the strongest response at low frequencies.
Incorporation of the thermal radiative effect of CH4, N2O, CF2Cl2, and CFCl3 into the National Center for Atmospheric Research community climate model
Authors: Wang Wei‐Chyung , Shi Guang‐Yu , Kiehl Jeffrey T.
Published: February 2008

This paper documents the incorporation of the radiative effect of trace gases CH4, N2O, CF2Cl2, and CFCl3 into the National Center for Atmospheric Research community climate model (CCMl) longwave scheme, which presently includes the radiative effect of H2O, CO2, and O3. This development is intended for using the CCMl to study the combined greenhouse effect of increasing atmospheric CO2, CH4, CF2Cl2, CFCl3, and N2O. The radiative effect of the trace gases in a homogeneous layer is parameterized based on Wang and Shi's (1988) analytical expression for the total band absorptance. For an inhomogeneous path, a scaling approximation is used to calculate the effective total band model parameters. The same treatment of the overlapping gaseous absorption bands used in the present CCMl scheme is adopted for the new trace gases.
A simple parameterization of ozone infrared absorption for atmospheric heating rate calculations
Authors: Rosenfield Joan E.
Published: February 2008

A simple parameterization of ozone absorption in the 9.6‐μm region which is suitable for two‐ and three‐dimensional stratospheric and tropospheric models is presented. The band is divided into two parts, a band center region and a band wing region, grouping together regions for which the temperature dependence of absorption is similar. Each of the two regions is modeled with a function having the form of the Goody random model, with pressure and temperature dependent band parameters chosen by empirically fitting line‐by‐line equivalent widths for pressures between 0.25 and 1000 mbar and ozone absorber amounts between 1.0×10−7 and 1.0 cm atm. The model has been applied to calculations of atmospheric heating rates using an absorber amount weighted mean pressure and temperature along the inhomogeneous paths necessary for flux computations. In the stratosphere, maximum errors in the heating rates relative to line‐by‐line calculations are 0.1 K/d, or 5% of the peak cooling at the stratopause. In the troposphere the errors are at most 0.005 K/d.
A comparison of measured and calculated optical properties of atmospheric aerosols at infrared wavelengths
Authors: Rosen James M.
Published: February 2008

Measurements of 10.6‐μm lidar backscatter were compared with calculated backscatter based on nearly simultaneous observations of stratospheric and tropospheric aerosol size distributions. It was found that there is better agreement in the troposphere, even though the uncertainties of the calculation are greater for this region due to the variabilities in both the spacial concentration and physical makeup of the aerosol. A second comparison study was made to test the consistency of the mean tropospheric extinction values at 1.02 μm (as reported by the SAGE satellite) with the values calculated from an ensemble of 400 measured size distributions thought to be representative of mid‐continental tropospheric aerosol. The two methods produce consistent results within the expected degree of uncertainty. The ensemble of 400 “proven” size distributions is then used to calculate a statistical relationship between the 1.02‐μm extinction and the 10.6‐μm backscatter.
Applications of the POCS inversion method to interpolating topography and other geophysical fields
Authors: Menke William
Published: February 2008

We apply the method of Projection Onto Convex Sets (POCS) to the problem of solving geophysical inverse problems. The advantage of this iterative method is its flexability in handling non‐linear equality and inequality constraints, including constraints on the spectrum of unknown functions. We give examples of using POCS to interpolate topographic profiles, topographic maps, and the physical properties of the earth between well logs.
Dipolarization: A consequence of substorm expansion onset
Authors: Kan J. R.
Published: February 2008

Dipolarization observed in the near‐Earth plasma sheet can be initiated by the substorm expansion onset. Field‐aligned currents at the substorm expansion onset are enhanced first in the ionosphere in response to an enhanced magnetospheric convection. Closure of substorm field‐aligned currents through the plasma sheet can disrupt the cross‐tail current to cause dipolarization in the plasma sheet. The electric field induced by the current disruption can launch a fast‐mode compression wave to result in the plasma injection event. A new X line can form tailward of the dipolarization region during the substorm expansion phase. A timing sequence of substorm events is inferred from the proposed conceptual model of substorms based on the magnetosphere‐ionosphere coupling process on the Alfvén bounce time scale.
Energy balance of the KOSI 4 Experiment
Authors: Grün E. , Benkhoff J. , Heidrich R. , Hesselbarth P. , Kohl H. , Kührt E.
Published: February 2008

A detailed energy analysis of an ice‐dust‐sample under interplanetary space conditions is presented. It is based on measurements obtained during a comet simulation (KOSI) experiment. Results of the analysis show that visible and thermal reradiation from the sample surface, the sublimation energy of the ices and the increase of internal heat are the most important contributions to the energy balance. At the beginning of irradiation a relatively high ice sublimation rate is observed. Dust particles remaining on the surface, build up a nonvolatile mantle, producing an obstacle for heat flow inwards and gas flow outwards. Consequences for cometary nuclei models are discussed.
An estimate of the Antarctic ozone modulation by the QBO
Authors: Mancini E. , Visconti G. , Pitari G. , Verdecchia M.
Published: February 2008

The possible effects of the QBO on the ozone distribution have been studied including in a 2D model a parameterization of Kelvin and Rossby‐gravity wave forcing in the lower equatorial stratosphere. A chemical code complete with heterogeneous reactions allows a simulation of the ozone depletion due to the increase of stratospheric chlorine. With this model we study the possible modulation of the secular trend in the Antarctic ozone hole by the QBO. When heterogeneous chemistry is not included, the model shows a polar ozone oscillation (±6 Dobson Units) comparable to that deduced from early measurements (1970–1975). When heterogeneous reactions are taken into account, the model predicts a larger ozone oscillation in the Southern Hemisphere (±12 Dobson Units) comparable to that obtained from recent observations. This behavior seems to point out a QBO induced temperature effect and its feedback on PSC with the activation of heterogeneous chemistry.
Evidence for unusually high densities of plasma in the Venusian ionosheath
Authors: Intriligator D. S. , Brace L. H. , Brecht S. H. , Knudsen W. C. , Scarf F. L. , Strangeway R. J. , Taylor H. A.
Published: February 2008

An unusual occurrence was recorded by Pioneer Venus Orbiter (PVO) in the Venusian ionosheath on November 10‐11, 1981 (orbit 1071): more than an order of magnitude higher densities of ions and electrons were observed than have ever been measured by PVO before then or since. This region of enhanced densities covered an extended region in the dayside ionosheath. The purpose of this paper is to briefly present our analysis of these unique observations.
Was the coppermine homocline of northwestern Canada uplifted as part of a Middle Proterozoic forebulge
Authors: Cook Frederick A.
Published: February 2008

Application of the principles of elastic plate bending to subsurface geometric information and outcrop in northwestern Canada suggests that Proterozoic crust was loaded and deflected during orogenic activity between about 1.6 and 1.1 Ga. Exposed Hudsonian (ca. 1.8–2.0 Ga) basement separating younger but coeval stratigraphic sequences in the Coppermine Homocline on the west and Bathurst Inlet on the east can be explained as a forebulge associated with the loading.
Magnetohydrodynamic fluctuations in the Earth's magnetosheath at 1500 LT: ISEE 1 and ISEE 2
Authors: Gleaves D. G. , Southwood D. J.
Published: February 2008

In the first study to employ dual‐spacecraft cross‐spectral techniques in the magnetosheath, we have analyzed ISEE 1 and ISEE 2 magnetic field and plasma data from an afternoon magnetosheath crossing to determine dominant MHD wave modes and directions. Our principal discovery is of guided MHD waves traveling along the flow‐modified wave characteristics (the curves along which wave energy is propagated in a flowing medium ‐ see, for example, Akhiezer et al. [1975]). Wave polarizations were determined by transforming the magnetic field to a field‐ and boundary‐aligned coordinate system. We have inferred wave propagation directions using the time delays between the passage of coherent structures across the spacecraft. Weaker broadband coherent oscillations in the direction radial from the planet could be associated with large scale motions of the shock and/or magnetopause, but the dominant signals appear not to be from such a source. Separate broadband Alfven and slow magnetoacoustic waves have been identified in the inner sheath, propagating across the field and flow toward the magnetopause. In the outer magnetosheath the most prominent disturbances were narrow‐band Alfven waves propagating downstream and along the field. The phase propagation directions detected for the largest amplitude signals were closely aligned with the flow‐modified wave characteristics, the group propagation directions. From this result, we infer that the sources of the dominant wave activity are localized MHD disturbances on the bow shock and not spatially coherent distributed sources such as bulk boundary motion. We suggest that the flow‐modified characteristics of the two field‐guided MHD modes may play an important role within the magnetosheath, determining the directions along which energy is transmitted between the solar wind and the magnetosphere.
Identification and observations of the plasma mantle at low altitude
Authors: Newell Patrick T. , Burke William J. , Meng Ching‐I. , Sanchez Ennio R. , Greenspan Marian E.
Published: February 2008

The direct injection of magnetosheath plasma into the cusp produces at low altitude a precipitation regime with an energy‐latitude dispersion—the more poleward portion of which we herein term the “cusp plume.” An extensive survey of the Defense Meteorological Satellite Program (DMSP) F7 and F9 32 eV to 30 keV precipitating particle data shows that similar dispersive signatures exist over much of the dayside, just poleward of the auroral oval. Away from noon (or more precisely, anywhere not immediately poleward of the cusp) the fluxes are reduced by a factor of about 10 as compared to the cusp plume, but other characteristics are quite similar. For example, the inferred temperatures and flow velocities, and the characteristic decline of energy and number flux with increasing latitude is essentially the same in a longitudinally broad ring of precipitation a few degrees thick in latitude over much of the dayside. We conclude that the field lines on which such precipitation occurs thread the magnetospheric plasma mantle over the entire longitudinally extended ring. Besides the location of occurrence (i.e., immediately poleward of the dayside oval), the identification is based especially on the associated very soft ion spectra, which have densities from a few times 10−2 to a few times 10−1/cm³; on the temperature range, which is from a few tens of eV up to about 200 eV; and on the characteristic gradients with latitude. Further corroborating evidence that the precipitation is associated with field lines which thread the plasma mantle includes drift meter observations which show that regions so identified based on the particle data consistently lie on antisunward convecting field lines. Our observations indicate that some dayside high‐latitude auroral features just poleward of the auroral oval are embedded in the plasma mantle.
The role of the ionosphere in coupling upstream ULF wave power into the dayside magnetosphere
Authors: Engebretson M. J. , Cahill L. J. , Arnoldy R. L. , Anderson B. J. , Rosenberg T. J. , Carpenter D. L. , Inan U. S. , Eather R. H.
Published: February 2008

A series of recent studies of Pc 3 magnetic pulsations in the dayside outer magnetosphere has given new insights into the possible mechanisms of entry of ULF wave power into the magnetosphere from a bow shock related upstream source. In this paper we first review many of these new observational results by presenting a comparison of data from two 10‐hour intervals on successive days in April 1986 and then present a possible model for transmission of pulsation signals from the magnetosheath into the dayside magnetosphere. Simultaneous multi‐instrument observations at South Pole Station, located below the cusp/cleft ionosphere near local noon, magnetic field observations by the AMPTE CCE satellite in the dayside outer magnetosphere, and upstream magnetic field observations by the IMP 8 satellite show clear interplanetary magnetic field field magnitude control of dayside resonant harmonic pulsations and band‐limited very high latitude pulsations, as well as pulsation‐modulated precipitation of what appear to be magnetosheath/boundary layer electrons. We believe that this modulated precipitation may be responsible for the propagation of upstream wave power in the Pc 3 frequency band into the high‐latitude ionosphere, from whence it may be transported throughout the dayside outer magnetosphere by means of an “ionospheric transistor.” In this model, modulations in ionospheric conductivity caused by cusp/cleft precipitation cause varying ionospheric currents with frequency spectra determined by the upstream waves; these modulations will be superimposed on the Birkeland currents, which close via these ionospheric currents. Modulated region 2 Birkeland currents will in turn provide a narrow‐band source of wave energy to a wide range of dayside local times in the outer magnetosphere.
A particle simulation of large‐amplitude undulations on the evening diffuse auroral boundary
Authors: Yamamoto Takashi , Makita K. , Meng C.‐I.
Published: February 2008

The pattern of undulation on the equatorward boundary of the diffuse aurora, occasionally observed in the afternoon‐evening sector, is studied by two‐dimensional particle simulations for the motion of magnetospheric plasma perpendicular to the geomagnetic field. In the simulation model, the poleward electric field is assumed to be initially enhanced locally in latitude and independent of longitude, as suggested by the observations near the undulations of the diffuse auroral boundary. Such an electric field is assumed to be maintained by space charges carried by a cold plasma. The diffuse aurora is initially distributed over a longitudinally extended zone. Since this type of diffuse aurora is probably caused by precipitation of the energetic protons with energies in excess of a few keV, the temporal evolution of the diffuse auroral pattern, as displayed in photographs from the satellites, can be visualized by following the cluster of the energetic protons. Sheared plasma flow arising from the electric field distribution drives the Kelvin‐Helmholtz instability and causes undulations on the equatorward boundary of the diffuse aurora with wavelengths and amplitudes comparable to the typical observed values. Notably, the particle simulation can reproduce the outstanding indentations characteristic of large‐amplitude undulations which have occasionally been observed. The good agreement between the simulation results and the observed undulations suggests that the Kelvin‐Helmholtz shear‐driven process is responsible for undulations on the equatorward boundary of the diffuse aurora in the afternoon‐evening sector. It is also shown that the magnetic drift of the energetic protons producing the diffuse aurora is important in creating the characteristic pattern of the diffuse auroral boundary.
Ion cyclotron waves near L = 4.6: A ground‐satellite correlation study
Authors: Ludlow G. R. , Hughes W. J. , Engebretson M. J. , Slavin J. A. , Sugiura M. , Singer H. J.
Published: February 2008

We present results of the first ground‐satellite correlation study of ion cyclotron wave events inside geosynchronous orbit. We found several intervals during which waves at the same frequency were observed simultaneously by the DE 1 Goddard Space Flight Center Fluxgate Magnetometer and by the Air Force Geophysics Laboratory Magnetometer Network. This represents about 33% of the intervals during which waves were seen on the ground and DE 1 was in a favorable location (near the geomagnetic equator around L = 4.6) to observe the wave generation region. Three of seven simultaneous events showed a positive correlation when a detailed correlation analysis was performed. The broadband nature of the other events prevented any detailed correlation analysis. Peaks in the cross‐correlation function occurred at delays of 30–100 s and are interpreted as the group delay time of signals from space to the ground station. The small number of events seen in space during conjunction intervals results from the satellite's path missing the source region. When sources are missed by the satellite path, they either exist at higher or lower L shells and are ducted in the ionosphere to the network (L = 3) or they exist at the satellite L shell but are missed due to their small spatial extent in local time.
An evaluation of the Tsyganenko Magnetic Field Model
Authors: Fairfield D. H.
Published: February 2008

A data set of more than 22,000 vector averages of the magnetosphere magnetic field over 0.5 RE regions is used to evaluate Tsyganenko's 1982 and 1987 magnetospheric magnetic field models. The magnetic field predicted by the model in various regions is compared to observations to find systematic discrepancies which future models might address. While agreement is generally good, discrepancies are noted which include: (1) a lack of adequate field line stretching in the tail and ring current regions; (2) an inability to predict weak enough fields in the polar cusps; and (3) a deficiency of Kp as a predictor of the field configuration.
Theory of electric fields in the auroral acceleration region
Authors: Tetreault David
Published: February 2008

Electric field fluctuations identified as electrostatic ion cyclotron waves, double layers, and near solitary wave potential structures have been observed in the auroral particle acceleration region by the S3‐3 and Viking satellites. Here these electric fields are explained in terms of a three‐dimensional model of nonlinear ion hole/clump instability. A novel feature of the instability is its occurrence in plasma that is linearly stable to ion acoustic and electrostatic ion cyclotron waves, the inferred state of the plasma in the auroral acceleration region. A growing ion hole has a double layer potential structure which, in the latter phase of the instability, decays to a near solitary wave potential structure. In addition, the holes can coexist with and be a source for electrostatic ion cyclotron waves. Instability thresholds, amplitudes for potentials, electric fields, and density depletions, as well as fluctuation velocities, lifetimes, scale sizes, and relative probablities for occurrence are calculated and compared with the satellite data.
A high‐latitude, low‐latitude boundary layer model of the convection current system
Authors: Siscoe G. L. , Lotko W. , Sonnerup B. U. Ö.
Published: February 2008

Observations suggest that both the high‐ and low‐latitude boundary layers contribute to magnetospheric convection, and that their contributions are linked. In the interpretation pursued here, the high‐latitude boundary layer (HBL) generates the voltage while the low‐latitude boundary layer (LBL) generates the current for the part of the convection electric circuit that closes through the ionosphere. However, the interpretation has a self‐consistency problem: in their magnetospheric settings, the two boundary layer generators are ostensibly independent, but in the ionosphere, Ohm's law ties the voltage to the current, and, thereby, couples them. This paper gives a model that joins the high‐ and low‐latitude boundary layers consistently with the ionospheric Ohm's law. It describes an electric circuit linking both boundary layers, the region 1 Birkeland currents, and the ionospheric Pedersen closure currents. The model works by using the convection electric field that the ionosphere receives from the HBL to determine two boundary conditions to the equations that govern viscous LBL'ionosphere coupling. The result provides the needed self‐consistent coupling between the two boundary layers and fully specifies the solution for the viscous LBL‐ionosphere coupling equations. The solution shows that in providing the current required by the ionospheric Ohm's law, the LBL needs only a tenth of the voltage that spans the HBL. (This has led to undervaluing the LBL's role in convection.) The solution also gives the latitude profiles of the ionospheric electric field, parallel currents, and parallel potential. The parallel currents span the convection reversal and shift both north and south relative to the polar cap boundary as the strength of the transpolar potential changes, offering an empirical test of the model. It predicts that the plasma in the inner part of the LBL moves sunward instead of antisunward and that, as the transpolar potential decreases below about 40 kV, reverse polarity (region 0) currents appear at the poleward border of the region 1 currents. A possible problem with the model is its prediction of a thin boundary layer (∼1000 km), whereas thicknesses inferred from satellite data tend to be greater.
On the Stenbaek‐Nielsen and Hallinan pulsating auroras
Authors: D'Angelo N.
Published: February 2008

The exceptionally thin pulsating auroral patches observed by Stenbaek‐Nielsen and Hallinan (1979) may be caused by an ionization instability occurring at the end of the range of precipitating electrons. A comparison is made to laboratory results reported by Johnson et al. (1990).
On acceleration of plasmoids in magnetohydrodynamic simulations of magnetotail reconnection
Authors: Scholer M. , Hautz R.
Published: February 2008

The formation and acceleration of plasmoids is investigated by two‐dimensional magnetohydrodynamic simulations. The initial equilibrium contains a plasma sheet with a northward magnetic field (Bz) component and a tailward pressure gradient. Reconnection is initiated by three different methods: Case A, a constant resistivity is applied everywhere and a tearing mode evolves, case B, a spatially localized resistivity is fixed in the near‐Earth region, and case C, the resistivity is allowed to depend on the electrical current density. In case A we obtain the same results as have been presented by Otto et al. (1990): the tearing instability releases the tension of the closed field lines so that the inherent pressure gradient of the two‐dimensional system is not balanced anymore. The pressure gradient then sets the plasmoid into motion. Any sling‐shot effect of open magnetic field lines is of minor importance. A completely different behavior has been found in cases B and C. In these cases the high‐speed flow in the wedge‐shaped region tailward of the near‐Earth neutral line pushes against the detached plasmoid and drives it tailward. The ideal terms contributing to the acceleration are still only the pressure and the magnetic field term. However, in these cases the pressure is due to the dynamic pressure of the fast outflow from the reconnection region. The outflow in the wedge‐shaped region on both sides of the neutral line is due to acceleration of plasma by tangential magnetic stresses at the slow mode shocks extending from the X line.