bluuebunny/crossref_metadata_2025 huggingface dataset:
Two Novel Cobalt(II) Coordination Polymers Based on the Herbicide Glyphosate as a Building Block and their Magnetic Properties
Authors: Han Guang‐Fan , Luo Hui‐Zhou , Ye Qiong , Xiong Ren‐Gen
Published: August 2008

The hydrothermal reaction of glyphosate and Co(Ac)2·4H2O in the presence of water and ethanol at different temperatures affords two novel cobalt coordination polymers: C12H30N4O20P4Co (1) and C3H10NO7P1Co (2). Both structures were determined by single crystal X‐ray diffraction. The coordination polymer of 1 is a one‐dimensional chain polymer with the crystal data: $\rm P{\bar 1}$, a = 5.5010(7), b = 10.983(2), c = 11.381(2) Å, α = 69.848(2), β = 86.645(2)°, γ = 79.788(2), V = 634.6(2) Å3, Z = 1, R1 = 0.0548, wR2 = 0.1557, whereas the coordination polymer of 2 is a two‐dimensional layered polymer with the crystal data: $\rm P{\bar 1}$, a = 8.9669(7), b = 7.3670(5), c = 12.7577(9) Å, β = 101.433(2)°, V = 826.04(10) Å3 Z = 4, R1 = 0.0325, wR2 = 0.1125. The glyphosate ligand exhibits different coordination behaviors in these two coordination polymers. Research on magnetic behavior revealed an antiferromagnetic coupling interaction between the Co2+ ions in both compounds.
Syntheses and Structures of Organotin(IV) Thioesters of N‐Phthaloylamino Acids
Authors: Fard Zohreh Hassanzadeh , Müller Christian , Dehnen Stefanie
Published: August 2008

Five organotin(IV) thioesters of N‐phthaloyl amino acids with the general formulae R3SnL (R = Me, Ph) and nBu2SnL2 were synthesized with L = N‐phthaloyl‐thioalanine and N‐phthaloyl‐thioleucine. The structures of trimethyltin(IV) N‐phthaloyl‐thioleucinate (1), trimethyltin(IV) N‐phthaloyl‐thioalaninate (2), triphenyltin(IV) N‐phthaloyl‐thioleucinate (3), triphenyltin(IV) N‐phthaloyl‐thioalaninate (4), and di‐n‐butyltin(IV) di‐N‐phthaloyl‐thioalaninate (5) were characterized by means of X‐ray diffractometry. Quantumchemical investigations served to clarify several structural peculiarities of the isolated compounds.
Drei Heterocubanartige (MII4O4)‐Typ Verbindungen (M = FeII, CoII, NiII)
Authors: Diewald S. , Lan Y. , Clérac R. , Powell A.‐K. , Feldmann C.
Published: August 2008

By reaction of MIICl2·x H2O (M = Fe (x = 4), Co, Ni (x = 6)) and LiOH·H2O in diethylene glycol (DEG) rod‐like crystals of the composition MII4Cl4(OCH2CH2OCH2CH2OH)4 are formed. According to X‐ray diffraction data obtained by both, single crystals and powders, the CoII and NiII compounds crystallize monoclinic with C2/c (CoII4Cl4(OCH2CH2OCH2CH2OH)4 (1): a = 2084.1(4), b = 919.0(2), c = 1754.0(4) pm, β = 124.3(1)°, Z = 4; NiII4Cl4(OCH2CH2OCH2CH2OH)4 (2): a = 2055.2(4), b = 932.1(2), c = 1727.4(4) pm, β = 125.2(1)°, Z = 4), whereas FeII4Cl4(OCH2CH2OCH2CH2OH)4 (3) crystallizes tetragonal with $\rm P{\bar 4}2_{1}c$ (a = 1251.4(2), c = 915.3(2) pm, Z = 2). All compounds exhibit analogous molecular structures which are built of a heterocubane‐type core consisting of four metal ions and four deprotonated oxygen atoms of four coordinated diethylene glycol molecules. Neutrality of charge is realized by additional coordination of four chloride anions. In addition to the structural characterization, the thermal and magnetical properties of the title compounds are investigated in detail.
Revealing the Crystal Structure of Anhydrous Calcium Oxalate, Ca[C2O4], by a Combination of Atomistic Simulation and Rietveld Refinement
Authors: Hochrein Oliver , Thomas Annu , Kniep Rüdiger
Published: August 2008

The existence of three different modifications of anhydrous calcium oxalate is reported since decades. Their crystal structures, however, remained unclear, yet. In the present work the crystal structure of the so‐called β‐modification was revealed by a combination of atomistic computer simulations and Rietveld refinements of the X‐ray powder pattern. No indication for polymorphism was obtained.
The Low and High Temperature Crystal Structures of [Mg(H2O)6]XBr3 Double Salts (X = Rb, Cs
Authors: Dinnebier Robert E. , Liebold‐Ribeiro Yvonne , Jansen Martin
Published: August 2008

The crystal structures of the alkali double salts [Mg(H2O)6]XBr3 (X = Rb+, Cs+) were analyzed in dependence on temperature from laboratory and synchrotron X‐ray powder diffraction data. At room temperature, both compounds are isostructural to [Mg(H2O)6](NH4)Br3 (C2/c; Z = 4; a = 9.64128(6) Å, b = 9.86531(5) Å, c = 13.78613(9) Å, β = 90.0875(5)° for [Mg(H2O)6]RbBr3; a = 9.82304(7) Å, b = 9.98043(6) Å, c = 14.0100(1) Å, β = 90.1430(4)° for [Mg(H2O)6]CsBr3). At a temperature of T = 358 K, [Mg(H2O)6]RbBr3 undergoes a reversible phase transition towards a cubic perovskite type of structure with the [Mg(H2O)6]2+ octahedron in the cuboctahedral cavity exhibiting 4‐fold disorder ($Pm{\bar 3}m$; a = 6.94198(1) Å at T = 458 K). In case of [Mg(H2O)6]CsBr3 the lattice parameters in dependence on temperature show a distinct kink at T = 340 K, but no symmetry breaking phase transition occurs before decomposition starts. The dominant role of hydrogen bonding with respect to the stability of the crystal structures is discussed.
Crystal Structure of the B‐type Dierbium Oxide ortho‐Oxosilicate Er2O[SiO4]
Authors: Phanon Delphine , Černý Radovan
Published: August 2008

The crystal structure of B‐type Er2O[SiO4] has been determined by single crystal X‐ray diffraction. It crystallizes with the (Mn,Fe)2[PO4]F type structure in the monoclinic space group C2/c (a = 14.366(2), b = 6.6976(6), c = 10.3633(16) Å, ß = 122.219(10)°, Z = 8) and shows anionic tetrahedral [SiO4]4– units and non‐silicon‐bonded O2– anions in distorted [OEr4]10+ tetrahedra. The [(Er1)O6+1] and [(Er2)O6] polyhedra form infinite chains which are connected by common edges.
New Transition‐Metal Borides containing Trigonal‐Planar B4‐Units: Syntheses and Single‐Crystal Structure Analyses of Ti1.6Os2.4B2 and Ti1–xFexOs2RhB2 (0 < x < 0.5)
Authors: Fokwa Boniface P. T. , Dronskowski Richard
Published: August 2008

Single crystals of Ti1.6Os2.4B2 and the solid solution Ti1–xFexOs2RhB2 (0 < x < 0.5) were synthesized by arc‐melting the elements in a water‐cooled copper crucible under an argon atmosphere. The new silver‐like phases, structurally characterized by single‐crystal X‐ray and EDX analyses, crystallize in the hexagonal Ti1.6Os1.4RuB2 structure type (space group $ P{\bar 6}2m$ (Nr. 189), Z = 3) and contain trigonal‐planar B4‐units and one‐dimensional chains of titanium or mixed titanium/iron atoms, respectively.
Tris(trifluoromethyl)borane Adducts of Cyanogen Halides
Authors: Geier Jens , Willner Helge
Published: August 2008

The reactivity of carbonyl‐tris(trifluoromethyl)borane (CF3)3BCO against the homologous series of cyanogen (pseudo)halides NCX, X = F, Cl, Br, I, CN, was investigated. Lewis acid‐base adducts (CF3)3BNCX were obtained for X = Cl, Br, I, CN and were characterized by vibrational and NMR spectroscopy. It appeared that FCN did not react and twofold complexation of NCCN does not occur, in agreement with theoretical complexation energies and QTAIM charges.
Biochemical and molecular diagnosis of erythropoietic protoporphyria in an Ashkenazi Jewish family
Authors: Schneider‐Yin X. , Mamet R. , Minder E. I. , Schoenfeld N.
Published: August 2008

Erythropoietic protoporphyria (EPP) is a rare hereditary disorder due to a partial deficiency of ferrochelatase (FECH). The genotype of EPP patients features a mutation on one allele of the FECH gene and a common hypomorphic FECH IVS3–48c on the other allele (M/c). The resulting enzyme activity in patients is ∼35% of that in normal individuals. Ferrochelatase deficiency results in the accumulation of protoporphyrin in the skin, which is responsible for the clinical symptom of cutaneous photosensitivity in patients. In this study, we report the identification of a novel FECH mutation delT23 in an 11‐member EPP family of Jewish origin. Two EPP siblings shared an identical genotype of delT23/IVS3–48c (M/c). They were both photosensitive and showed highly increased erythrocyte protoporphyrin. The genotype of the patients’ mother, who did not present with any EPP clinical symptoms, was delT23/IVS3–48t (M/t). The patients’ father, an offspring of consanguineous parents, was homozygous IVS3–48 c/c. He exhibited a mild photosensitivity, and an increase of 4‐fold in erythrocyte protoporphyrin. His FECH mRNA amount was 71% of that of genotype t/t. It is the first reported case of an individual with c/c genotype who exhibits both biochemical and clinical indications of EPP. These results suggest that IVS3–48c is a functional variant of ferrochelatase. The clinical symptoms and biochemical abnormalities in the patients’ father could be the result of an interaction between genetic and environmental factors. In addition, the frequency of IVS3–48c in the Ashkenazi Jewish population was estimated at 8%, which is similar to that in the European populations.
Efficiency and safety of oxcarbazepine in mood disorders: A naturalistic study exploring the interest of plasma dosages
Authors: Misdrahi David , Tournier Marie , Droulout Tiphaine , Grolleau Adeline , Titier Karine , Molimard Mathieu , Verdoux Helene
Published: August 2008

Objective

To investigate whether measurement of plasma levels can predict tolerance to oxcarbazepine (OXC).

Methods

We reviewed medical records to identify all inpatients consecutively treated by OXC at the University Department of Psychiatry in Bordeaux. Adverse effects were rated before treatment onset, at day 3, then every week and at discharge or at discontinuation. Residual hydroxy-OXC concentrations were measured on blood samples at the same periods.

Results

OXC was prescribed to 20 patients with bipolar (n = 18) or schizoaffective bipolar-type disorder (n = 2). Reported side effects were transient and occurred mostly at the beginning of the treatment. Three patients stopped OXC because of severe cutaneous side effects. Residual hydroxy-OXC plasma levels were similar in patients with or without occurrence of side effects at all times of assessment.

Conclusion

Our data suggest that the occurrence of severe side-effects is relatively high with OXC. Measurement of plasma OXC levels does not appear to be of interest in clinical practice since plasma concentrations are not predictive of the occurrence of side effects.
Pelvic organ prolapse in rural Ghana
Authors: Wusu‐Ansah Osei K. , Opare‐Addo Henry S.
Published: August 2008

Objective

To determine the prevalence of pelvic organ prolapse (POP) and its impact on the lives of women in Sekyidumasi, a rural Ghanaian community.

Methods

A cross‐sectional study of 200 women was performed using a questionnaire and pelvic examination to detect symptoms and signs of prolapse. Main outcome measures were the presence of POP and its impact on quality of life.

Results

Out of 174 women included in the study, 21 women (12.07%) had POP. Seventeen of these women (81%) were symptomatic, of which only 6 women (35.3%) had sought treatment because of financial constraints. The odds of prolapse increased with increasing parity (P = 0.02) and age (P < 0.01). The main impacts of prolapse were on emotional well‐being (52.4%), the women's relationship with their partner (46.2%), and sex life (25%).

Conclusion

Only about one‐third of women with symptomatic prolapse sought treatment because the cost of medical care outweighed the impact of the condition on their lives.
Erratum to “Bargaining in Legislatures over Particularistic and Collective Goods” American Political Science Review 101(1): 79–92.
Authors: VOLDEN CRAIG , WISEMAN ALAN E.
Published: August 2008

The symmetric, stationary subgame-perfect Nash equilibrium in Volden and Wiseman (2007) is characterized by cutpoints between regions of purely collective, mixed, and purely particularistic budget allocations. The cutpoints in our published article were derived by finding conditions under which the proposer receives a higher utility in one region than in another. However, a stationary equilibrium requires that the proposer would not unilaterally offer a different type of proposal, given that all other players continue to play their present strategies.
Effects of ascorbic acid, phytic acid and tannic acid on iron bioavailability from reconstituted ferritin measured by anin vitrodigestion–Caco-2 cell model
Authors: Jin Fuxia , Frohman Charles , Thannhauser Theodore W. , Welch Ross M. , Glahn Raymond P.
Published: August 2008

The effects of ascorbic acid (AA), phytate and tannic acid (TA) on Fe bioavailability from Fe supplied as reconstituted ferritin were compared with FeSO4using anin vitrodigestion–Caco-2 cell model. Horse spleen apoferritin was chemically reconstituted into an animal-type ferritin (HSF) and a plant-type ferritin (P-HSF) according to the typical ratios of Fe:P found in these molecules. In the presence of AA (Fe:AA molar ratio of 1:20), significantly more Fe was absorbed from FeSO4(about 303 %), HSF (about 454 %) and P-HSF (about 371 %) when compared with ferrous sulfate or ferritin without AA. Phytic acid (PA; Fe:PA molar ratio of 1:20) significantly reduced Fe bioavailability from FeSO4(about 86 %), HSF (about 82 %) and P-HSF (about 93 %) relative to FeSO4and the ferritin controls. Treatment with TA (Fe:TA molar ratio of 1:1) significantly decreased Fe bioavailability (about 97 %) from both FeSO4and the ferritin samples. AA was able to partially reverse the negative effect of PA (Fe:PA:AA molar ratio of 1:20:20) on Fe bioavailability but did not reverse the inhibiting effect of TA (Fe:TA:AA molar ratio of 1:1:20) on Fe bioavailability from ferritin and FeSO4. Overall, there were no significant differences in bioavailable Fe between P-HSF, HSF or FeSO4. Furthermore, the addition of AA (a known promoter) or the inhibitors, PA and TA, or both, did not result in significant differences in bioavailable Fe from ferritin relative to FeSO4. The results suggest that Fe in the reconstituted ferritin molecule is easily released duringin vitrodigestion and interacts with known promoters and inhibitors.
Serum leptin levels in overweight children and adolescents
Authors: Antunes Henedina , Santos Cristina , Carvalho Susana
Published: August 2008

Leptin is an adipocyte-secreted hormone which plays a key role in energy homeostasis. Our aim was to determine the relationship between serum leptin and clinical and biochemical features in overweight children and adolescents. Overweight children and adolescents followed in this Unit with serum leptin ascertained were included. Clinical, biochemical and abdominal ultrasound data were analysed. Statistical analysis was performed byttest, χ2, Pearson's correlation and linear regression. One outlier of serum leptin was excluded to perform correlation and regression. Serum leptin was determined in 357 patients. At the first visit, the mean age was 9·5 (sd3·2) years and mean BMIz-score was 1·72 (sd1·34) (girls 1·71 (sd1·16); boys 1·72 (sd1·11)). Serum leptin levels were significantly related to: sex (mean: girls 48·0 ng/ml, boys 34·4 ng/ml;P = 0·003); Tanner stage (mean: I–II 37·0 ng/ml, III–V 45·2 ng/ml;P = 0·035); systolic blood pressure (mean: normal 41·3 ng/ml, high 44·0 ng/ml;P = 0·009); BMIz-score (r0·136;P = 0·010); C-peptide (r0·17;P = 0·002); insulin (r0·34;P < 0·001); homeostasis model assessment of insulin resistance (HOMA-IR) (r0·25;P < 0·001) and aspartate aminotransferase (r− 0·12;P = 0·023). In the multivariate analysis (with leptin as the dependent variable and sex, Tanner stage, BMIz-score, systolic blood pressure, aspartate aminotransferase, C-peptide, insulin and HOMA-IR as independent variables), sex and BMI were determinant factors. The present study in overweight children and adolescents showed that being female and greater BMI were significantly and independently associated with increased serum leptin. In this large cohort other associations with leptin described in the literature can be discharged.
Helminth communities of the autochthonous mustelids Mustela lutreola and M. putorius and the introduced Mustela vison in south-western France
Authors: Torres J. , Miquel J. , Fournier P. , Fournier-Chambrillon C. , Liberge M. , Fons R. , Feliu C.
Published: August 2008

This study presents the first comprehensive helminthological data on three sympatric riparian mustelids (the European mink Mustela lutreola, the polecat M. putorius and the American mink M. vison) in south-western France. One hundred and twenty-four specimens (45 M. lutreola, 37 M. putorius and 42 M. vison) from eight French departments were analysed. Globally, 15 helminth species were detected: Troglotrema acutum, Pseudamphistomum truncatum, Euryhelmis squamula, Euparyphium melis and Ascocotyle sp. (Trematoda), Taenia tenuicollis (Cestoda), Eucoleus aerophilus, Pearsonema plica, Aonchotheca putorii, Strongyloides mustelorum, Molineus patens, Crenosoma melesi, Filaroides martis and Skrjabingylus nasicola (Nematoda) and larval stages of Centrorhynchus species (Acanthocephala). The autochthonous European mink harboured the highest species richness (13 species) followed by the polecat with 11 species. The introduced American mink presented the most depauperate helminth community (nine species). The prevalence and worm burden of most of the helminths found in M. putorius and M. lutreola were also higher than those of M. vison. Some characteristics of their helminth communities were compared to relatively nearby populations (Spain) and other very distant populations (Belarus). This comparison emphasized M. patens as the most frequent parasite in all of the analysed mustelid populations. It was possible to conclude that the invasive M. vison contributes to the maintenance of the life cycle of the pathogenic T. acutum and S. nasicola helminths, with possible implications for the conservation of the endangered European mink.
Sprachlich-kognitive Kompetenzen beim Eintritt in den Kindergarten
Authors: Dubowy Minja , Ebert Susanne , von Maurice Jutta , Weinert Sabine
Published: August 2008

Zusammenfassung. Im Mittelpunkt der Arbeit steht die Frage, ob und in welcher Weise sich die sprachlichen und kognitiven Kompetenzen von Kindern mit und ohne Migrationshintergrund zu Beginn der Kindergartenzeit unterscheiden. Innerhalb der Gruppe von Familien mit Migrationshintergrund wird ergänzend die Bedeutung ausgewählter familiärer Merkmale, wie Muttersprache der Hauptbetreuungsperson, Alltagssprache in der Familie und wahrgenommene Integration für die deutschen Sprachkompetenzen des Kindes analysiert. Untersucht wurden 547 Kinder (119 mit und 428 ohne Migrationshintergrund), die zum Zeitpunkt der Erhebung im Schnitt 3;8 Jahre alt waren. Die Ergebnisse zeigen, dass Kinder mit Migrationshintergrund in einem weiten Kompetenzspektrum standardisierter Testverfahren schwächere Leistungen erreichen als ihre deutschen Altersgenossen. Dieser Befund wird für die einzelnen Kompetenzbereiche getrennt diskutiert, wobei insbesondere die Bedeutung der unterschiedlichen sprachlichen Anregung in den verschiedenen Subgruppen thematisiert wird.
Kurz- und langfristige Effekte mathematischer Frühförderung im Kindergarten durch das Programm „Mengen, zählen, Zahlen”
Authors: Krajewski Kristin , Nieding Gerhild , Schneider Wolfgang
Published: August 2008

Zusammenfassung. Es werden Befunde aus einer ersten Erprobung des mathematischen Frühförderprogramms „Mengen, zählen, Zahlen” (MZZ; Krajewski, Nieding & Schneider, 2007 ) berichtet. Insgesamt 260 Vorschulkinder nahmen im Verlauf ihres letzten Kindergartenjahres an verschiedenen Fördermaßnahmen teil. Neben der Gruppe mit MZZ-Förderung wurde eine weitere Gruppe mit einem Training induktiven Denkens gefördert. Die Kontrollgruppe erhielt im gleichen Zeitraum (Okt–Dez) kein spezifisches Training; ein Teil dieser Kinder wurde jedoch unter nicht-kontrollierten Bedingungen zwischen Mai und Juli mit einem anderen mathematischen Frühförderprogramm trainiert. Ein Jahr sowie acht bzw. zwei Monate vor Schuleintritt wurden spezifische und unspezifische Vorläuferkompetenzen erhoben. Nur für die Kinder der MZZ-Gruppe konnten Fördereffekte im Bereich der mathematischen Vorläuferkompetenzen (Mengen-Zahlen-Kompetenzen) nachgewiesen werden. Keine Effekte zeigten sich hingegen auf nicht-mathematikspezifische Kompetenzen (z.B. phonologische Bewusstheit, Arbeitsgedächtnis).
Eine Googleyse 1Eigene Wortkreation. zur Musiktherapie
Authors: Müller-Greiff Julian
Published: August 2008

Zusammenfassung. Der Autor präsentiert Ergebnisse einer Internetrecherche zum Thema Musiktherapie. Einleitend werden Methodik und Relevanz der Recherche anhand der geschichtlichen Entwicklung kurz erläutert. Mit Hilfe der Suchmaschine Google wurde die Präsenz des Begriffs „Musiktherapie”, in deutscher und englischer Sprache in Relation zu anderen Begrifflichkeiten analysiert. Ergebnisse des Vergleichs mit anderen Therapieformen und Städten, die einen musiktherapeutischen Studiengang anbieten, werden tabellarisch dargestellt und abschließend diskutiert.
Risk perception, risk communication and health behavior change
Authors: Renner Britta , Schupp Harald , Vollmann Manja , Hartung Freda-Marie , Schmälzle Ralf , Panzer Martina
Published: August 2008

Abstract. At a broad level, the Konstanz Health Psychology research group aims at understanding the judgment and decision making processes underlying health-relevant behaviors. Towards this goal, several more specific research agendas are addressed. A primary aim is to understand the transition from knowing about risks to personally feeling at risk. In particular, we study the reception of relevant personalised health feedback such as feedback on cholesterol levels or blood pressure. Contrary to the dominant models of biased reasoning, our results on feedback reception suggest that people respond adaptively to health risk feedback. Furthermore, we study changes in the perception of health risk across time and their associated effects on the onset, maintenance, and cessation of health-relevant behaviors. In current research, we try to utilize methods from affective neuroscience for assessing affective and intuitive processes relevant to personal feelings of risk. These efforts are motivated by the broader goal of developing theoretical frameworks that can be applied across a range of behavioral domains.
Nonlinear Change Models in Populations with Unobserved Heterogeneity
Authors: Kelley Ken
Published: August 2008

When unobserved heterogeneity exists in populations where the phenomenon of interest is governed by a functional form of change linear in its parameters, the growth mixture model (GMM) is useful for modeling change conditional on latent class. However, when the functional form of interest is nonlinear in its parameters, the GMM is not very useful because it is based on a system of equations linear in its parameters. The nonlinear change mixture model (NCMM) is proposed, which explicitly addresses unobserved heterogeneity in situations where change follows a nonlinear functional form. Due to the integration of nonlinear multilevel models and finite mixture models, neither of which generally have closed form solutions, analytic solutions do not generally exist for the NCMM. Five methods of parameter estimation are developed and evaluated with a comprehensive Monte Carlo simulation study. The simulation showed that the parameters of the NCMM can be accurately estimated with several of the proposed methods, and that the method of choice depends on the precise question of interest.
The 1870 space weather event: Geomagnetic and auroral records
Authors: Vaquero J. M. , Valente M. A. , Trigo R. M. , Ribeiro P. , Gallego M. C.
Published: August 2008

The great solar storm that took place on 24–25 October 1870 is not well known and has been almost absent from previous studies. In this work, a large amount of information that was registered at the time is compiled and analyzed, including early geomagnetic data and several comprehensive descriptions of the auroras observed during these two nights. These descriptions reveal unusual characteristics for a typical low‐latitude aurora. For example, unlike most low‐latitude auroras (generally red and diffuse), this event was mostly characterized by a variable palette of colors, including greenish and white. The geomagnetic records analyzed from Lisbon and Coimbra (Portugal), Greenwich (United Kingdom), Munich (Germany), and Helsinki (Finland) clearly show an intense geomagnetic disturbance on 24–25 October. The Coimbra magnetograms reveal that this disturbance consisted of two distinct geomagnetic storms, the first on 24 October (with amplitudes of 37′ in D and 182 nT and 48 nT in H and Z, respectively), and the second on 25 October (with amplitudes of 33′ in D and 281 nT and 192 nT in H and Z, respectively). Finally, from early photographic solar observations made during 1870, we have identified a long‐lived group of sunspots that are most likely related to the solar source of this great event of space weather.
Deep crustal structure of the Paraná Basin from receiver functions and Rayleigh‐wave dispersion: Evidence for a fragmented cratonic root
Authors: Julià J. , Assumpção M. , Rocha M. P.
Published: August 2008

The deep crustal structure of the Paraná Basin of southern Brazil is investigated by analyzing P‐ and PP‐wave receiver functions at 17 Brazilian Lithosphere Seismic Project stations within the basin. The study area can be described as a typical Paleozoic intracratonic basin that hosts one of the largest Large Igneous Province of the world and makes a unique setting for investigating models of basin subsidence and their interaction with mantle plumes. Our study consists of (1) an analysis of the Moho interaction phases in the receiver functions to obtain the thickness and bulk Vp/Vs ratio of the basin's underlying crust and (2) a joint inversion with Rayleigh‐wave dispersion velocities from an independent tomographic study to delineate the detailed S‐wave velocity variation with depth. The results of our analysis reveal that Moho depths and bulk Vp/Vs ratios (including sediments) vary between 41 and 48 km and between 1.70 and 1.76, respectively, with the largest values roughly coinciding with the basin's axis, and that S‐wave velocities in the lower crust are generally below 3.8 km/s. Select sites within the basin, however, show lower crustal S‐wave velocities slightly above 3.9 km/s suggestive of underplated mafic material. We show that these observations are consistent with a fragmented cratonic root under the Paraná basin that defined a zone of weakness for the initial Paleozoic subsidence of the basin and which allowed localized mafic underplating of the crust along the suture zones by Cenozoic magmatism.
Ground‐level nitrogen dioxide concentrations inferred from the satellite‐borne Ozone Monitoring Instrument
Authors: Lamsal L. N. , Martin R. V. , van Donkelaar A. , Steinbacher M. , Celarier E. A. , Bucsela E. , Dunlea E. J. , Pinto J. P.
Published: August 2008

We present an approach to infer ground‐level nitrogen dioxide (NO2) concentrations by applying local scaling factors from a global three‐dimensional model (GEOS‐Chem) to tropospheric NO2 columns retrieved from the Ozone Monitoring Instrument (OMI) onboard the Aura satellite. Seasonal mean OMI surface NO2 derived from the standard tropospheric NO2 data product (Version 1.0.5, Collection 3) varies by more than two orders of magnitude (<0.1–>10 ppbv) over North America. Two ground‐based data sets are used to validate the surface NO2 estimate and indirectly validate the OMI tropospheric NO2 retrieval: photochemical steady‐state (PSS) calculations of NO2 based on in situ NO and O3 measurements, and measurements from a commercial chemiluminescent NO2 analyzer equipped with a molybdenum converter. An interference correction algorithm for the latter is developed using laboratory and field measurements and applied using modeled concentrations of the interfering species. The OMI‐derived surface NO2 mixing ratios are compared with an in situ surface NO2 data obtained from the U.S. Environmental Protection Agency's Air Quality System (AQS) and Environment Canada's National Air Pollution Surveillance (NAPS) network for 2005 after correcting for the interference in the in situ data. The overall agreement of the OMI‐derived surface NO2 with the corrected in situ measurements and PSS‐NO2 is −11–36%. A larger difference in winter/spring than in summer/fall implies a seasonal bias in the OMI NO2 retrieval. The correlation between the OMI‐derived surface NO2 and the ground‐based measurements is significant (correlation coefficient up to 0.86) with a tendency for higher correlations in polluted areas. The satellite‐derived data base of ground level NO2 concentrations could be valuable for assessing exposures of humans and vegetation to NO2, supplementing the capabilities of the ground‐based networks, and evaluating air quality models and the effectiveness of air quality control strategies.
First successful prediction of a convective equatorial ionospheric storm using solar wind parameters
Authors: Kelley M. C. , Retterer J.
Published: August 2008

One of the major challenges of the National Space Weather Program in the United States is to predict the generation of intense turbulence in the equatorial and low‐latitude ionosphere. We term this a convective equatorial ionospheric storm since, much like a thunderstorm, low‐density media erupt upward, releasing stored gravitational energy. This is an important phenomenon since both communication and navigational systems can be severely affected by the associated turbulence. Here, for the first time, we use solar wind data obtained upstream of the Earth and a physics‐based assimilative model to successfully predict such an event during a strong magnetic storm in November 2004.
Modeling excess air and degassing in groundwater by equilibrium partitioning with a gas phase
Authors: Aeschbach‐Hertig Werner , El‐Gamal Hany , Wieser Martin , Palcsu Laszlo
Published: August 2008

Studies involving dissolved conservative gases in groundwater have usually found a gas excess above atmospheric solubility equilibrium (excess air), but sometimes also gas depletion (degassing). Both excesses and deficits of dissolved gases in groundwater can be explained by interactions with trapped gas bubbles. Excess air is formed when trapped air dissolves under increased pressure, degassing may occur if biogenic gases exsolve or pressure decreases. The concept of closed‐system equilibration between groundwater and trapped bubbles (CE‐model) proved successful in modeling excess air. Here we show that this concept can also be used to model the loss of dissolved gases and compare its performance to alternative models assuming a diffusion‐controlled degassing process. We find that for samples from laboratory tests and a shallow groundwater well that consistently exhibits gas undersaturation, the CE‐model provides the best available, albeit not perfect, description of degassing.
Simple model representations of transport in a complex fracture and their effects on long‐term predictions
Authors: Tsang Chin‐Fu , Doughty Christine , Uchida Masahiro
Published: August 2008

A complex fracture model for fluid flow and tracer transport that incorporates many of the important physical effects of a realistic fracture, including advection through a heterogeneous fracture plane, partitioning of flow into multiple subfractures in the third dimension, and diffusion and sorption into fracture‐filling gouge, small altered rock matrix blocks within the fracture zone, and the unaltered semi‐infinite rock matrix on both sides of the fracture zone, was previously developed. It is common, however, to represent the complex fracture by much simpler models consisting of a single fracture, with a uniform or heterogeneous transmissivity distribution over its plane and bounded on both sides by a homogeneous semi‐infinite matrix. Simple‐model properties are often inferred from the analysis of short‐term (one to a few days) site characterization (SC) tracer test data. The question addressed in this paper is: How reliable is the temporal upscaling of these simplified models? Are they adequate for long‐term calculations that cover thousands of years? In this study, a particle‐tracking approach is used to calculate tracer test breakthrough curves (BTCs) in a complex fracture model, incorporating all the features described above, for both a short‐term SC tracer test and a 10,000‐year calculation. The results are considered the “real world”. Next, two simple fracture models, one uniform and the other heterogeneous, are introduced. Properties for these simple models are taken either from laboratory data or found by calibration to the short‐term SC tracer test BTCs obtained with the complex fracture model. Then the simple models are used to simulate tracer transport at the long‐term timescale. Results show that for the short‐term SC tracer test, the BTCs calculated using simple models with laboratory‐measured parameters differ significantly from the BTCs obtained with the complex fracture model. By adjusting model properties, the simple models can be calibrated to reproduce the peak arrival time and height of the complex fracture model BTCs, but the overall match remains quite poor. Using simple models with short‐term SC‐calibrated parameters for long‐term calculations yields BTCs with order‐of‐magnitude errors: peak arrival time is 10 to 100 times too late, and peak height is 50 to 300 times too small. On the other hand, using simple models with laboratory‐measured properties of unfractured rock samples for 10,000‐year calculations yields BTCs with peak arrivals and heights up to a factor of 50 too early and large, respectively. The actual magnitudes of the errors made by using the simple models depend on the parameter values assumed for the complex fracture model, but in general, simple models are not expected to provide reliable long‐term predictions. The paper concludes with some suggestions on how to improve long‐term prediction calculations.
Changes in global land monsoon area and total rainfall accumulation over the last half century
Authors: Zhou Tianjun , Zhang Lixia , Li Hongmei
Published: August 2008

This study reports the changes of global land monsoon coverage and monsoon rainfall accumulation. We showed that the combination of monsoon area and rainfall intensity change has led to an overall weakening trend of global land monsoon rainfall accumulation during the last 54 years. This decreasing tendency is mainly caused by the North African monsoon and South Asian monsoon, due to the significant decreasing tendencies of both rainfall intensity and monsoon coverage. The long‐term changes of the other monsoon subsystems are not significant in the context of regional average. The monsoon area and rainfall accumulation indices are consistent with the rainfall intensity index in revealing both the inter‐decadal and interannual variability. The former appears as an inter‐decadal oscillation with a peak phase through 1970‐1980; the latter appears as the North African, North American and Australian monsoons having stronger spectrum power in the LF (3‐7yr) band, while the South African, South and East Asian monsoons having greater powers in the QB (2‐3yr) band.
Semiannual variation in the western tropical Pacific Ocean
Authors: Qu Tangdong , Gan Jianping , Ishida Akio , Kashino Yuji , Tozuka Tomoki
Published: August 2008

Analysis of altimeter data combined with results from a high‐resolution general circulation model has revealed the existence of a semiannual variation in the western tropical Pacific. The semiannual variation cannot be explained by local Ekman pumping alone, but is also related to the westward propagation of Rossby waves originating in the central tropical Pacific, corresponding in the northern hemisphere with the Inter‐Tropical Convergence Zone and in the southern hemisphere with the South Pacific Convergence Zone. This signal intensifies toward the western boundary and appears to have a notable impact on the circulation there. In the Mindanao Current, the semiannual variation is of comparable strength with the annual variation. This finding is supported by a moored acoustic Doppler current profile measurement during the period from October 1999 to July 2002.
Synchronous deposition of volcanic ash and sulfate aerosols over Greenland in 1783 from the Laki eruption (Iceland)
Authors: Wei Lijia , Mosley‐Thompson Ellen , Gabrielli Paolo , Thompson Lonnie G. , Barbante Carlo
Published: August 2008

Sulfate aerosols from the 1783–1784 A.D. Laki eruption are widely used as a reference horizon for constraining Greenland ice core time scales, yet the timing of the arrival of the sulfate remains under discussion. Two ice cores from western Greenland, analyzed with high temporal resolution, confirm that sulfate aerosols arrived over Greenland late in 1783, concomitant with the tephra, elevated concentrations of Cd, Bi, and Tl, all indicators of volcanic emissions, and with a short‐lived Rare Earth Elements anomaly. Thereafter sulfate deposition declined rapidly. Very modest concentrations of sulfate in 1784 snowfall, evident in six Greenland cores, suggest a relatively short (less than 1 year) atmospheric residence time and an injection height limited to the lower stratosphere. An improved estimate of the associated stratospheric sulfate burden is calculated and provides an important input for models assessing climatic impacts of this volcanic eruption.
Cytoplasmic polyadenylation-element-binding protein (CPEB)1 and 2 bind to the HIF-1α mRNA 3′-UTR and modulate HIF-1α protein expression
Authors: Hägele Sonja , Kühn Uwe , Böning Melanie , Katschinski Dörthe M.
Published: August 2008

The heterodimeric HIF (hypoxia-inducible factor)-1 is a transcriptional master regulator of several genes involved in mammalian oxygen homoeostasis. Besides the well described regulation of the HIF-1α subunit via hydroxylation-mediated protein stability in hypoxia, there are several indications of an additional translational control of the HIF-1α mRNA, especially after growth factor stimulation. We identified an interaction of CPEB (cytoplasmic polyadenylation-element-binding protein) 1 and CPEB2 with the 3′-UTR (untranslated region) of HIF-1α mRNA. Overexpression of CPEB1 and CPEB2 affected HIF-1α protein levels mediated by the 3′-UTR of HIF-1α mRNA. Stimulation of neuroblastoma SK-N-MC cells with insulin and thus activation of endogenous CPEBs increased the expression of a luciferase reporter gene fused to the 3′-UTR of HIF-1α as well as endogenous HIF-1α protein levels. This could be abrogated by treating the cells with CPEB1 or CPEB2 siRNAs (short interfering RNAs). Injection of HIF-1α cRNA into Xenopus oocytes verified the elongation of the poly(A)+ (polyadenylated) tail by cytoplasmic polyadenylation. Thus CPEB1 and CPEB2 are involved in the regulation of HIF-1α following insulin stimulation.
Optical properties and phase change transition in Ge2Sb2Te5 flash evaporated thin films studied by temperature dependent spectroscopic ellipsometry
Authors: Orava J. , Wágner T. , Šik J. , Přikryl J. , Frumar M. , Beneš L.
Published: August 2008

We studied the optical properties of as-prepared (amorphous) and thermally crystallized (fcc) flash evaporated Ge2Sb2Te5 thin films using variable angle spectroscopic ellipsometry in the photon energy range 0.54–4.13 eV. We employed Tauc–Lorentz (TL) model and Cody–Lorentz (CL) model for amorphous phase and TL model with one additional Gaussian oscillator for fcc phase data analysis. The amorphous phase has optical bandgap energy Egopt=0.65 eV (TL) or 0.63 eV (CL) slightly dependent on used model. The Urbach edge of amorphous thin film was found to be ∼70 meV. Both models behave very similarly and accurately fit to the experimental data at energies above 1 eV. The CL model is more accurate in describing dielectric function in the absorption onset region. The thickness decreases ∼7% toward fcc phase. The bandgap energy of fcc phase is significantly lower than amorphous phase, Egopt=0.53 eV. The temperature dependent ellipsometry revealed crystallization in the range 130–150 °C. The bandgap energy of amorphous phase possesses temperature redshift −0.57 meV/K (30–110 °C). The crystalline phase has more complex bandgap energy shift, first +0.62 meV/K (150–180 °C) followed by −0.29 meV/K (190–220 °C). The optical properties (refractive index, extinction coefficient, and optical bandgap energy) of as-prepared and fcc flash evaporated Ge2Sb2Te5 thin films are very similar to those values previously reported for sputtered thin films.
A study of the zona piercing process in piezodriven intracytoplasmic sperm injection
Authors: Gan Yong , Chen Zhen
Published: August 2008

The mouse zona piercing process in piezodriven intracytoplasmic sperm injection (piezo-ICSI) is modeled and simulated with the material point method (MPM) to study the physics behind the piercing process. The MPM simulation reveals that the lateral vibration of the injection pipette plays a key role in the piercing process and disproves the claim that the axial displacement of the pipette pierces the zona. The lateral vibration of the injection pipette is further analyzed using the finite element method to investigate the role of mercury in the piercing process. It is shown that the use of mercury generally reduces the amplitude of the pipette tip and that a shorter piezopulse duration results in a smaller vibration amplitude. This implies that the effect of mercury on the piezo-ICSI procedure may lie in causing less oocyte damage due to the reduced amplitude of the pipette tip, and the development of a piezo-ICSI procedure without using mercury is possible by changing the dimensions of the injection micropipette and the piezodrill controller parameters.
Asymptotic counting of BPS operators in superconformal field theories
Authors: Lucietti James , Rangamani Mukund
Published: August 2008

We consider some aspects of counting BPS operators which are annihilated by two supercharges in superconformal field theories. For nonzero coupling, the corresponding multivariable partition functions can be written in terms of generating functions for vector partitions or their weighted generalizations. We derive asymptotics for the density of states for a wide class of such multivariable partition functions. We also point out a particular factorization property of the finite N partition functions. Finally, we discuss the concept of a limit curve arising from the large N partition functions, which is related to the notion of a “typical state,” and discuss some implications for the holographic duals.
Electrical spin injection and optical detection in InAs based light emitting diodes
Authors: Stier A. V. , Meining C. J. , McCombe B. D. , Chado I. , Grabs P. , Schmidt G. , Molenkamp L. W.
Published: August 2008

Results of low temperature circularly polarized electroluminescence (EL) studies of InAs-based spin-light emitting diodes in magnetic fields up to 10 T are presented. Spin polarized electrons injected from cubic n-(CdMn)Se recombine with unpolarized holes resulting in emission with a positive degree of optical polarization over this entire magnetic field range. Detailed rate equation modeling of the optical polarization degree (OPD) confirms a high spin injection efficiency (74%–95%) and a spin lifetime τs longer than the optical recombination time τr. Estimates of the temperature dependence of the ratio τr/τs from the OPD are compared with the Elliot–Yafet and Dyakonov–Perel models.
Investigation on doping dependency of solution-processed Ga-doped ZnO thin film transistor
Authors: Park Won Jun , Shin Hyun Soo , Ahn Byung Du , Kim Gun Hee , Lee Seung Min , Kim Kyung Ho , Kim Hyun Jae
Published: August 2008

Ga-doped ZnO (GZO) thin film transistors (TFTs) were fabricated based on the solution-processed method and GZO TFTs were investigated according to the variation of the Ga doping concentration [Ga∕Zn (%)]. A field-effect mobility of 1.63cm2∕Vs and a drain current on/off ratio of 4.17×106 were observed in the 5.4 % Ga-doped TFT. This result shows good agreement with its structural properties and electrical properties of the GZO channel layer. It is believed that the optimal and desirable electrical properties of the TFTs can be obtained by adjusting the Ga doping concentration.
Measurement of crack opening stresses and crack closure stress profiles from heat generation in vibrating cracks
Authors: Renshaw Jeremy , Holland Stephen D. , Thompson R. Bruce
Published: August 2008

A method is described to measure crack opening stresses and closure stress profiles of a surface-breaking crack. Vibration is used to generate frictional heat by rubbing crack face asperities. Heat is generated at regions of contacting crack asperities under low, but nonzero, closure stress. Increasing force is applied to incrementally open the crack and measure the locations of crack heating as a function of applied load. Surface crack closure stresses are approximated from the heating locations as the load is varied and the crack opening stress is measured from the load required to fully open the crack and terminate heat generation.
Direct electrical measurement of an individual α-Fe2O3 nanobridge field effect transistor formed via one-step thermal oxidation
Authors: Hsu Li-Chieh , Li Yuan-Yao
Published: August 2008

An α-Fe2O3 nanobridge (NB) was laterally grown via the one-step thermal oxidation of 150 nm Fe film at 350 °C for 1 h in air atmosphere to form a NB field effect transistor (FET). The diameter of the as-grown NB was 7 nm, with a length of 170 nm. The electrical properties of the individual α-Fe2O3 NB were directly measured by microprobing the NB FET. The results show that the NB demonstrated N-type semiconductive behavior with a conductivity of 1.67 S/cm.
Thin-film sensing with planar asymmetric metamaterial resonators
Authors: Al-Naib Ibraheem A. Ibraheem , Jansen Christian , Koch Martin
Published: August 2008

We propose rectangular asymmetric double split resonators with field confining tips for use as thin-film sensors. In contrast to frequency selective surfaces, which consist of two-dimensional, periodic resonator arrays, only a single unit cell placed inside a rectangular waveguide is sufficient for sensing. Compared to circular structures, the rectangular design offers a miniaturization. Furthermore, the tips at the end of the resonator arms concentrate the field components into a small area, increasing the volumetric sensitivity of the device.
Electronic and transport properties of contacts between molybdenum sulfide nanowires and gold electrodes
Authors: Popov Igor , Pecchia Alessandro , Okano Shinya , Ranjan Nitesh , Di Carlo Aldo , Seifert Gotthard
Published: August 2008

We report unique electronic and transport properties of contacts between a molybdenum sulfide nanowire and a gold electrode. The pointlike contacts exhibit a remarkable transparency for the charge carrier injection, which is the consequence of the “task division” between sulfur and molybdenum atoms at the interface with the gold electrode, where sulfur binds the nanowire to the electrode, and the current flows unperturbed through the direct Au–Mo channels. The unique properties of the analyzed contacts solve some major drawbacks in the molecular electronics devices, such as the difficulties for the current injection from the electrodes into conjugated carbon-based molecules.