bluuebunny/crossref_metadata_2025 huggingface dataset:
Pattern Evolution Induced by Periodic Temperature Modulation in a Binary Polymeric Mixture
Authors: Sun Zhe , Song Haihua
Published: May 2006

Summary: The process of periodic phase separation is numerically studied based on Cahn‐Hilliard‐Cook theory for a binary polymer blend. The model system is quenched blow and above the critical point alternatively. And hierarchic morphologies consisting of large and small domains are observed. As the periodic phase separation proceeds, small domains are created and destroyed periodically, whereas large domains keep growing. Within the first half of each period, the behavior of small domains is similar to the two‐step phase separation. And the quench to one‐phase region during the second half period not only decreases the peak intensity of structure function for large domains, but also eliminates the high‐wave number peak corresponding to small domains. The average order parameter under oscillatory quenches exhibits a periodic behavior. The minimum of average order parameter in each period approaches to its equilibrium value monotonously and the maximum value increase in the early time regime and decrease in the late time regime. The magnitude of oscillation has considerable effects on the evolution of hierarchic structures. Small magnitude of oscillation hinders the formation of hierarchic morphologies. Moreover, large magnitude of oscillation slows down the coarsening of large domains in the early stage of periodic phase separation and accelerates the growth of large domains in the late time regime. In addition, no scaling invariance could be observed for the net growth of large domains.

Snapshot picture of periodic phase separation with \bar \chi, Δχ, and τp.

magnified image

Snapshot picture of periodic phase separation with \bar \chi, Δχ, and τp.
Transurethral radiofrequency energy collagen micro‐remodeling for the treatment of female stress urinary incontinence
Authors: Appell Rodney A. , Juma Saad , Wells W. Glen , Lenihan John P. , Klimberg Ira W. , Kanellos Angelo , Reilley Sandra F.
Published: May 2006

Aims

This prospective, randomized, controlled clinical trial was performed to demonstrate the 12 months safety and efficacy of transurethral radiofrequency energy (RF) collagen micro‐remodeling in women with stress urinary incontinence (SUI).

Materials and Methods

Women with SUI, bladder outlet hypermobility, and leak point pressure (LPP) ≥60 cmH2O were randomized to RF micro‐remodeling or “sham treatment.” Adverse events (AEs) were recorded. Incidence of ≥10 point incontinence quality of life (I‐QOL) score improvement, a magnitude of improvement with a demonstrated responsiveness to patient satisfaction with treatment and to ≥25% reduction in both incontinence episode frequency and stress pad weight, served as a subjective outcome measurement. Change in mean LPP served as an objective outcome measurement.

Results

110 women underwent RF micro‐remodeling and 63 underwent virtually identical “sham treatment” (with the exception of RF delivery). The 12 months RF micro‐remodeling safety profile was statistically no different than that of sham treatment (a brief bladder catheterization). Seventy‐four percent of women with moderate to severe baseline SUI experienced ≥10 point I‐QOL score improvement at 12 months (P = 0.04). Women who underwent RF micro‐remodeling demonstrated LPP elevation at 12 months, while sham treated women demonstrated LPP reduction (P = 0.02).

Conclusions

Non‐surgical, transurethral RF micro‐remodeling is a safe treatment for women with SUI. In women with moderate to severe SUI, this novel therapy resulted in statistically significant improvement in quality of life of a magnitude associated with patient satisfaction with the treatment. Women who underwent RF micro‐remodeling demonstrated a statistically significant elevation in mean LPP at 12 months. Neurourol. Urodynam. © 2006 Wiley‐Liss, Inc.
Emergency transshipment in decentralized dealer networks: When to send and accept transshipment requests
Authors: Zhao Hui , Deshpande Vinayak , Ryan Jennifer K.
Published: May 2006

While there has been significant previous literature on inventory transshipment, most research has focused on the dealers' demand filling decision (when to fill transshipment requests from other dealers), ignoring the requesting decision (when to send transshipment requests to other dealers). In this paper we develop optimal inventory transshipment policies that incorporate both types of decisions. We consider a decentralized system in which the dealers are independent of the manufacturer and of each other. We first study a network consisting of a very large number of dealers. We prove that the optimal inventory and transshipment decisions for an individual dealer are controlled by threshold rationing and requesting levels. Then, in order to study the impact of transshipment among independent dealers in a smaller dealer network, we consider a decentralized two‐dealer network and use a game theoretic approach to characterize the equilibrium inventory strategies of the individual dealers. An extensive numerical study highlights the impact of the requesting decision on the dealers' equilibrium behavior in a decentralized setting. © 2006 Wiley Periodicals, Inc. Naval Research Logistics, 2006
Site‐specific interactions of neurotrophin‐3 and fibroblast growth factor (FGF2) in the embryonic development of the mouse cochlear nucleus
Authors: Hossain Waheeda A. , D'Sa Chrystal , Morest D. Kent
Published: May 2006

Neurotrophins and FGF2 contribute to formation of the cochlea, but their roles in cochlear nucleus development are unknown. The effects of these factors may differ in the cochlea and cochlear nucleus, which may influence each other's development. It is important to analyze the effects of these factors on cellular structures at well‐defined steps in the normal morphogenetic sequence. The present study used immunohistochemistry to localize factors in situ and to test hypotheses about their roles in an in vitro model. Specific antibody staining revealed that TrkC, the NT3 receptor, is present in neural precursors prior to embryonic day E11 until after birth. NT3 appeared in precursor cells during migration (E13–E15) and disappeared at birth. TrkC and NT3 occurred in the same structures, including growing axons, terminals, and their synaptic targets. Thus, NT3 tracks the migration routes and the morphogenetic sequences within a window defined by TrkC. In vitro, the cochlear nucleus anlage was explanted from E11 embryos. Cultures were divided into groups fed with defined medium, with or without FGF2, BDNF, and NT3 supplements, alone or in combinations, for 7 days. When neuroblasts migrated and differentiated, immunostaining was used for locating NT3 and TrkC in the morphogenetic sequence, bromodeoxyuridine for proliferation, and synaptic vesicle protein for synaptogenesis. By time‐lapse imaging and quantitative measures, the results support the hypothesis that FGF2 promotes proliferation and migration. NT3 interacts with FGF2 and BDNF to promote neurite outgrowth, fasciculation, and synapse formation. Factors and receptors localize to the structural sites undergoing critical changes. © 2006 Wiley Periodicals, Inc. J Neurobiol, 2006
Fabrication of GaN dot structures on Si substrates by droplet epitaxy
Authors: Kondo Toshiyuki , Saitoh Koji , Yamamoto Yo , Maruyama Takahiro , Naritsuka Shigeya
Published: May 2006

Nanosized GaN dot structures were fabricated on Si(111) substrate by droplet epitaxy using an rf plasma MBE system. The size and density of the GaN dots could be controlled by changing the amount of Ga supplied. By reducing the Ga supply, a maximum dot density of 3.3 × 1011 cm–2 was realized. Photoluminescence measurements at room temperature showed band edge emission with negligible yellow luminescence, which indicates a good optical property of GaN dots grown by this technique. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Ge[N(SiMe2iPr)2]2: Ein neues Germylen und dessen Koordinationschemie führt zu der kürzesten Ge–Co‐Bindung
Authors: Schnepf Andreas
Published: May 2006

Ge[N(SiMe2iPr)2]2: A New Germylene and its Coordination Chemistry leads to the Shortest Ge–Co Bond

The high temperature reaction of Germanium with HBr, which is used for the synthesis of GeBr leads at a higher reaction pressure to a mixture of GeBr and GeBr2. GeBr2 reacts with the lithiumsalt LiN(SiMe2iPr)2 in good yield to the germylene Ge[N(SiMe2iPr)2]2. Subsequent reaction of this germylene with Co2(CO)8 leads to the germanium cobalt cluster compound {Co(CO)3Ge[N(SiMe2iPr)2]2}2 featuring the shortest Ge–Co bond giving hints to a possibly multiple bonded system.
Two Different Products Observed in the Reaction of a Bis(germylene) with Molybdenum Hydride [Mo(H)Cp(CO)3]
Authors: Krummenacher Ivo , Breher Frank
Published: May 2006

The reaction of the dimeric bis(germylene) [Ge{3,5‐(CF3)2pz}2]2 (2) with protic molybdenum hydride [Mo(H)Cp(CO)3] yielded two different products. In diethyl ether the divalent germylene readily inserts into the Mo–H σ‐bond and the product of the oxidative addition, [Ge(H){Mo}(pz)2] (4) (with pz = 3,5‐disubstituted pyrazole, 3,5‐(CF3)2pz; {Mo} = [MoCp(CO)3]), was isolated featuring a germanium(IV) hydride moiety. In toluene an interesting “cascade” reaction takes place furnishing a bis‐metal substituted digermane [{Mo}(H)(pz)Ge–Ge(pz)2{Mo}]. Although the detailed mechanism of the reaction remains the subject of speculation it seems likely that a germylene, [GeII(pz){Mo}], inserts into the germanium(IV) hydrogen bond of [Ge(H){Mo}(pz)2] under formation of a germanium‐germanium bond, which is a rare reaction behaviour.
Crystal Structures of the Potassium and Silver Salts of Nitroform
Authors: Göbel Michael , Klapötke Thomas M. , Mayer Peter
Published: May 2006

The solid state structures of three nitroformate (NF) salts were determined using single crystal X‐ray crystallography. The NF anion was found to be a non‐planar moiety which adopts either the commonly observed C2v conformation or distorted propeller conformation (D3) in the case of the silver salts, or, a C2 conformation in the case of the potassium salt. This latter C2 conformation has been uniquely observed for potassium nitroformate. All structures exhibit cation‐anion interactions that influence the structure of the anion. The 13C and 14N NMR spectra of the NF anion show broad singlets, which indicates the equivalence of the nitro groups in solution within the NMR time‐scale. In addition, the vibrational and mass spectra of potassium nitroformate and silver nitroformate monohydrate were recorded. Furthermore, the gaseous decomposition products of potassium nitroformate at 25 °C were detected using IR spectroscopy and mass spectrometry.
Ungewöhnliche Bildung und Struktur eines O‐Sulfinato‐Zinkkomplexes
Authors: Ibrahim Mohamed M. , Vahrenkamp Heinrich
Published: May 2006

Unusual Formation and Structure of a O‐Sulfinato Zinc Complex

Whereas the reaction between hydrotris[(N‐xylyl)‐thioimidazolyl]borato‐zinc perchlorate ([L·Zn‐OClO3]) and ethanethiolate under an inert atmosphere leads to the thiolate complex [L·Zn‐SC2H5], the same reaction in air produces the sulfinato complex [L·Zn‐O‐S(O)‐C2H5] (1). 1 is the first fully characterized sulfinato‐zinc complex. Its structure determination has confirmed the unusual coordination of the sulfinato ligand via one of its oxygen atoms.
1,2‐Diaza‐3‐silacyclopent‐5‐ene – Synthese und Reaktionen
Authors: Armbruster Nina , Klingebiel Uwe , Noltemeyer Mathias
Published: May 2006

1,2‐Diaza‐3‐silacyclopent‐5‐ene – Synthesis and Reactions

The dilithium salt of bis(tert‐butyl‐trimethylsilylmethylen)ketazine (1) forms an imine‐enamine salt. 1 reacts with halosilanes in a molar ratio of 1:1 to give 1,2‐diaza‐3‐silacyclopent‐5‐enes. Me3SiCH=CCMe3 [N(SiR,R′)‐N=C‐C]HSiMe3 (2‐7). (2: R,R′ = Cl; 3: R = CH3, R′ = Ph; 4: R = F, R′ = CMe3; 5: R = F, R′ = Ph; 6: R = F, R′ = N(SiMe3)2; 7: R = F, R′ = N(CMe3)SiMe3). In the reaction of 1 with tetrafluorosilane the spirocyclus 8 is isolated. The five‐membered ring compounds 2‐7 and compound 9 substituted on the silicon‐fluoro‐ and (tert‐butyltrimethylsilyl) are acid at the C(4)‐atom and therefore can be lithiated. Experiments to prepare lithium salts of 4 with MeLi, n‐BuLi and PhLi gave LiF and the substitution‐products 10‐12. 9 forms a lithium salt which reacts with ClSiMe3 to give LiCl and the SiMe3 ring system (13) substituted at the C(4)‐atom. The ring compounds 3‐7 and 10‐12 form isomers, the formation is discussed. Results of the crystal structure and analyses of 8, 10, 12, and 13 are presented.
Evidence for p53‐like‐mediated stress responses in green algae
Authors: Nedelcu Aurora M.
Published: May 2006

The tumor suppressor protein, p53, plays a major role in cellular responses to stress and DNA damage in animals; despite its critical function, p53 homologs have not been identified in any algal or plant lineage. This study employs a functional and evolutionary approach to test for a p53 functional equivalent in green algae. Specifically, the study: (i) investigated the effect of two synthetic compounds known to interfere with p53 activity; (ii) searched for sequences with similarity to known p53‐induced genes; and (iii) analyzed the expression pattern of one such sequence. The findings reported here suggest that a p53 functional equivalent is present and mediates cellular responses to stress in green algae.
Detecting transient protein–protein interactions by X‐ray absorption spectroscopy: The cytochrome c6‐photosystem I complex
Authors: Díaz-Moreno Irene , Díaz-Quintana Antonio , Subías Gloria , Mairs Trevor , De la Rosa Miguel A. , Díaz-Moreno Sofía
Published: May 2006

Reliable analysis of the functionality of metalloproteins demands a highly accurate description of both the redox state and geometry of the metal centre, not only in the isolated metalloprotein but also in the transient complex with its target. Here, we demonstrate that the transient interaction between soluble cytochrome c
6 and membrane‐embedded photosystem I involves subtle changes in the heme iron, as inferred by X‐ray absorption spectroscopy (XAS). A slight shift to lower energies of the absorption edge of Fe2+ in cytochrome c
6 is observed upon interaction with photosystem I. This work constitutes a novel application of XAS to the analysis of weak complexes in solution.
Genetic networks responsive to sodium butyrate in colonic epithelial cells
Authors: Tabuchi Yoshiaki , Takasaki Ichiro , Doi Takeshi , Ishii Yoshiyuki , Sakai Hideki , Kondo Takashi
Published: May 2006

We performed microarray and computational gene network analyses to identify the detailed mechanisms by which sodium butyrate (SB) induces cell growth arrest and the differentiation of mouse colonic epithelial MCE301 cells. Two thousand six hundred four differentially expressed probe sets were identified in the cells treated with 2 mM SB and were classified into four groups. Of these, the gradually increased group and the gradually and remarkably decreased group contained the genetic networks for cellular development and cell cycles or canonical pathways for fatty acid biosynthesis and pyrimidine metabolism, respectively. The present results provide a basis for understanding the detailed molecular mechanisms of action of SB in colonic epithelial cells.
The α‐helix of the second chromodomain of the 43 kDa subunit of the chloroplast signal recognition particle facilitates binding to the 54 kDa subunit
Authors: Hermkes Rebecca , Funke Silke , Richter Christine , Kuhlmann Jürgen , Schünemann Danja
Published: May 2006

Chloroplasts of higher plants contain a unique signal recognition particle (cpSRP) that consists of two proteins, cpSRP54 and cpSRP43. CpSRP43 is composed of a four ankyrin repeat domain and three functionally distinct chromodomains (CDs). In this report we confirm previously published data that the second chromodomain (CD2) provides the primary binding site for cpSRP54. However, quantitative binding analysis demonstrates that cpSRP54 binds to CD2 significantly less efficiently than it binds to full‐length cpSRP43. Further analysis of the binding interface of cpSRP by mutagenesis studies and a pepscan approach demonstrates that the C‐terminal α‐helix of CD2 facilitates binding to cpSRP54.
HIGH‐FIBER, LOW‐FAT DIET HAS LITTLE EFFECT ON WEIGHT
Authors: Snapp Carol A.
Published: May 2006

Howard BV, Manson JE, Stefanik ML, Beresford SA, Frank G, Jones B, et al. Low‐fat dietary pattern and weight change over 7 years: The Women's Health Initiative dietary modification trial. JAMA 2006;295:39–49.
The Estrogen Alternative: A Guide to Natural Hormonal Balance, 4th edition
Authors: Van Hoover Cheri , McDonald Kimla
Published: May 2006

By Raquel Martin and Judi Gerstung, Rochester, VT: Healing Arts Press, 2005. 352 pages. $16.95, softcover.
Levels of evidence in otolaryngology journals
Authors: Wasserman Jared M. , Wynn Rhoda , Bash Tal S. , Rosenfeld Richard M.
Published: May 2006

OBJECTIVE

To identify trends in clinical research and levels of evidence in otolaryngology journals.

STUDY DESIGN AND SETTING

We reviewed all original research articles from 1993, 1998, and 2003, in 4 major otolaryngology journals. Levels of evidence were graded 1 (strongest) through 5 (weakest).

RESULTS

Of 2584 total articles, 1924 (75%) were clinical research. During the study period, there was increased median sample size (from 22 to 30, P = 0.06), more planned research (from 30% to 37%, P = 0.023), more internal control groups (from 36% to 43%, P = 0.011), and more articles with P values (from 26% to 45%, P < 0.001) or confidence intervals (from 1.2% to 7.6%, P < 0.001). Most evidence was level 4 (57%), but median levels increased slightly over time (P = 0.027). Therapy articles had the weakest evidence (80% levels 3 to 5) and diagnostic test assessments had the strongest (75% levels 1 and 2).

CONCLUSION

Although clinical research increased in quantity and quality, sample sizes were modest, most articles lacked controls, and confidence intervals were rare. Therapy articles would benefit from higher evidence levels.

SIGNIFICANCE

By defining the current levels of evidence in otolaryngology journals, this overview should help guide future efforts.
The Effect of Hyoid Suspension in a Multilevel Surgery Concept for Obstructive Sleep Apnea
Authors: Baisch Alexander , Maurer Joachim Theodor , Hörmann Karl
Published: May 2006

OBJECTIVE

This study investigated the outcome of the hyoid suspension as a part of a multilevel surgery protocol.

STUDY DESIGN AND SETTING

Eighty‐three patients with obstructive sleep apnea (OSA) underwent a multilevel surgical treatment because of continuous positive‐airway pressure intolerance, 67 with the hyoid suspension and 16 without the hyoid suspension. All patients underwent a pre‐ and postoperative polysomnography in the sleep laboratory.

RESULTS

The mean preoperative apnea hypopnea index (AHI) was 36.4 ± 21.2 and 19.4 ± 19.7 postoperatively for all patients (P < 0.0001). Further statistically significant changes were found for the arousal index, the oxygen saturation, and the daytime sleepiness. No statistically significant change was found for body mass index. In the group of patients treated without the hyoid suspension, the AHI did not decrease statistically significant. After surgery, 59.7% of the subjects with the hyoid suspension were regarded as cured.

CONCLUSION

Multilevel surgery including the hyoid suspension is an effective treatment in subgroup of OSA patients.

EBM rating: C‐4
DISCRETION, NOLLE PROSEQUI AND THE 1992 GHANAIAN CONSTITUTION
Authors: MENSAH KWADWO BOATENG
Published: May 2006

Section 54 of Ghana's Criminal Procedure Code, 1960 (Act 30), gives the Attorney-General discretion to enter a nolle prosequi in the course of a criminal trial. According to the orthodox view, this discretionary power is not subject to judicial review. The orthodox view raises a number of very important questions. First, is it really the case that the power to enter a nolle prosequi is not subject to judicial review? Secondly, if this is the case, how is the Attorney-General accountable for the manner in which he exercises his discretion and how is it possible to ensure that he acts fairly when he enters a nolle prosequi? This article challenges the orthodox theory and advocates a theory based on legal accountability. The proposed theory is founded on the view that accountability and fairness—which are central constituents of good governance—will be enhanced if the discretion to enter a nolle prosequi is subject to legal control. The paper goes on to show that the legal accountability theory is supported by article 296 of the 1992 Ghanaian Constitution and that it also conforms to practices found in other Commonwealth jurisdictions such as England, Canada, Fiji and Australia.
Simulation of plunging wave impact on a vertical wall
Authors: Zhang Sheguang , Yue Dick K. P. , Tanizawa Katsuji
Published: May 2006

We present a numerical study of the impact of a two-dimensional plunging wave on a rigid vertical wall in the context of potential flow. The plunging wave impinging the wall is generated using a mixed-Eulerian-Lagrangian (MEL) boundary-integral scheme. The initial stage of the impact is characterized by an oblique impact of a liquid wedge on the wall and is solved using a similarity solution. Following the initial impact, the MEL simulation is continued to capture the transient impact process. The effect of an air cushion trapped between the plunger and the wall is considered. In addition to details such as temporal evolutions and surface profiles, the main interests are the maximum impact pressure on the wall and its rise time. To arrive at appropriate scaling laws for these, simulations are performed and correlations are explored for a broad range of local plunging wave kinematic and geometric parameters. To assess the present results, direct comparisons are made with the experiment of Chan & Melville (1988). Reasonable quantitative agreement is obtained and likely sources for discrepancies are identified and discussed.
Recurrent outbreaks of cryptosporidiosis associated with calves among students at an educational farm programme, Minnesota, 2003
Authors: KIANG K. M. , SCHEFTEL J. M. , LEANO F. T. , TAYLOR C. M. , BELLE-ISLE P. A. , CEBELINSKI E. A. , DANILA R. , SMITH K. E.
Published: May 2006

Enteric illness outbreaks among middle-/high-school students in consecutive semesters of an educational farm programme were investigated with retrospective cohort studies. During the first outbreak, 31/92 (34%) interviewed students were ill. Risk factors included participating in animal science class (RR 8·1, 95% CI 1·2–55·2) and contact with calves (RR 4·2, 95% CI 1·1–16·2). Stool samples from seven students and two calves yielded Cryptosporidium parvum. Students cared for animals in street clothes and practised poor hand washing. During the second outbreak, 37/81 (46%) interviewed animal science students were ill. Risk factors included having visible manure on hands, and wearing coveralls and boots. Stool samples from seven students and eight calves yielded C. parvum. Student hand washing was still inadequate. Coveralls/boots were cleaned infrequently and removed after hand washing. These outbreaks of cryptosporidiosis resulted from calf contact and inadequate hygiene practices. The failure to adequately implement recommended interventions contributed to the second outbreak.
Hydrothermal mineral deposits and fossil biota from a young (0.1 Ma) abyssal hill on the flank of the fast spreading East Pacific Rise: Evidence for pulsed hydrothermal flow and tectonic tapping of axial heat and fluids
Authors: Benjamin Sara B. , Haymon Rachel M.
Published: May 2006

Heat flow data indicate that most hydrothermal heat loss from ocean lithosphere occurs on the flanks of the mid‐ocean ridge, but few ridge flank hydrothermal sites are known. We describe the first nonseamount, abyssal hill hydrothermal mineral deposits to be recovered from the fast spreading East Pacific Rise (EPR) flanks. Deposits were sampled at two sites on an abyssal hill ∼5 km east of the EPR axis, just north of Clipperton Fracture Zone at 10°20′N, on ∼0.1 Ma lithosphere. “Tevnia Site” is on the axis‐facing fault scarp of the hill, and “Ochre Site” is located ∼950 m farther east near the base of the outward‐facing slope. Clusters of fragile, biodegradable Tevnia worm tubes at both sites indicate that hydrothermal fluids carried sufficient H2S to sustain Tevnia worms, and that fluid flow waned too recently to allow time for tube destruction. Presence of microbial mats and other biota also are consistent with recent waning of flow. The deposits are mineralogically zoned, from nontronite‐celadonite to hydrous Fe‐oxide+opaline silica to Mn‐oxide (birnessite and todorokite). This places them into a distinctive class of Fe‐Si‐Mn hydrothermal deposits found along tectonic cracks and faults in young oceanic crust, and suggests that (1) deposits precipitated along an O2 gradient between ambient seawater and hydrothermal fluid; (2) fluid temperatures were <150°C; and (3) undiluted fluids were Mg‐depleted, and Fe‐, K‐, Si‐ and Mn‐enriched. These fluids may derive from high temperature seawater‐basalt interaction ± phase separation proximal to the axial melt zone, and lose Cu and Zn before venting due to conductive cooling and/or pH increase. Ochre Site samples are purely hydrothermal; however, Tevnia Site samples incorporate volcanic, sedimentary, and fossil components, and exhibit at least three generations of fracturing and hydrothermal cementation. The Tevnia Site breccias accumulated on the exposed fault scarp, possibly during multiple slip events and hydrothermal pulses as the abyssal hill was uplifted. We hypothesize that frequent earthquakes rejuvenate young abyssal hill hydrothermal systems episodically over 104–105 years, tapping axial heat and hydrothermal fluids, sustaining biota, and likely helping to chill the margins of the axial melt zone.
Source of the 1693 Catania earthquake and tsunami (southern Italy): New evidence from tsunami modeling of a locked subduction fault plane
Authors: Gutscher M.‐A. , Roger J. , Baptista M.‐A. , Miranda J. M. , Tinti S.
Published: May 2006

The 1693 Catania earthquake, which caused 60000 deaths in eastern Sicily and generated a 5–10 m high tsunami, is investigated. GPS data indicate ESE‐WNW convergence in the Calabrian arc at 4–5 mm/yr. New high‐resolution seismic data image active compression at the toe of the accretionary wedge. The lack of instrumentally recorded thrust earthquakes suggests the presence of a locked subduction fault plane. Thermal modeling is applied to calculate the limits of the seismogenic zone. Tsunami modeling is performed to test the hypothesis that the 1693 earthquake occurred on the subduction fault plane (160 × 120 km in size) with 2 m of mean co‐seismic slip. This source successfully reproduces historical observations with regard to polarity and predicts 1–3 m high amplitudes. It is likely that only the SW segment of the subduction fault plane ruptured in 1693 and 1169, implying a recurrence interval of roughly 500 years for similar events.
Temporal variance of lower mesospheric ozone over Switzerland during winter 2000/2001
Authors: Hocke Klemens , Kämpfer Niklaus , Feist Dietrich G. , Calisesi Yasmine , Jiang Jonathan H. , Chabrillat Simon
Published: May 2006

The Stratospheric Ozone Monitoring Radiometer (SOMORA) is continuously operated in Switzerland and measures ozone volume mixing ratio in the stratosphere and lower mesosphere with a time resolution of about 30 min. Temporal variances S (wave period band 1–3 h) of daytime and nighttime ozone are studied at an altitude of 55 km from October 1, 2000 to May 1, 2001. Gravity waves are assumed as cause of the observed short‐time fluctuations of Strong negative and positive correlations are found between the dynamic state of the stratosphere (represented by time series of ERA‐40 reanalyses) and SOMORA's S and series of lower mesospheric ozone. Oscillations with periods of 5–30 days are present in the S and series.
Influence of volcanic activity and changes in solar irradiance on surface air temperatures in the early twentieth century
Authors: Shiogama Hideo , Nagashima Tatsuya , Yokohata Tokuta , Crooks Simon A. , Nozawa Toru
Published: May 2006

Causes of the global surface air temperature warming in the early half of the 20th century are examined using a climate model and an optimal detection/attribution methodology. While the anthropogenic response seems to be underestimated in our model, our previous study detected the influence due to natural external forcing, including the combined effects of solar irradiance changes and the recovery from large volcanic activity. We further partition the responses between these two natural external factors, detecting both the solar and the volcanic signal in the observed early warming. A diagnosis of the sensitivity to solar forcing and a volcanic super‐eruption simulation suggest that our model possesses larger climate sensitivities to solar forcing and longer relaxation times to volcanic forcing than HadCM3, enabling us to detect both the solar and volcanic forcing responses.
Initial simulation results of storm‐time ring current in a self‐consistent magnetic field model
Authors: Liu S. , Chen M. W. , Schulz M. , Lyons L. R.
Published: May 2006

The storm‐time ring current generates a strong and time‐dependent perturbation of the magnetospheric magnetic field , and this magnetic‐field perturbation can have important feedback on the dynamics of ring current particles themselves. In particular, the modification of can significantly alter the gradient‐curvature drifts of ring current particles, and the induced electric field associated with ∂/∂t can inhibit ring current particle injection and energization. Thus in order to accurately simulate the storm‐time ring current, a self‐consistent magnetic field model that takes these effects into account is needed. This study is our first attempt to address this issue. We assume for simplicity a model for such that magnetic field lines lie in meridional planes and satisfy the generic Dungey field line equation. With these two assumptions and given the pressure distribution in the equatorial plane, the force‐balanced magnetic field in the equatorial plane is obtained by solving the force balance equation. This force balance equation solver is coupled with our ring current model to provide self‐consistent magnetic fields. In this study, we simulate a hypothetical storm with this magnetically self‐consistent ring current model. By comparing our simulation results with statistical studies, we find that our model reasonably reproduces the disturbed magnetic field in the equatorial plane in terms of magnitude and location. The equatorial current density shows an inner eastward ring current at ∼3 RE, and a outer westward ring current at ∼4–6.6 RE, which agrees well with observations. The effects of the self‐consistent magnetic field on the dynamics of ring‐current particles are discussed. We find that the self‐consistent magnetic field tends to prevent ring current particles from deep injection and to mitigate the energization of ring current particles. Thus the ring current simulated in a self‐consistent magnetic field model will produce less of a disturbance at the center of the Earth than that simulated in the prescribed dipole or dipole‐like magnetic field models without feedback from the ring current.
Tracking halo coronal mass ejections from 0–1 AU and space weather forecasting using the Solar Mass Ejection Imager (SMEI)
Authors: Howard T. A. , Webb D. F. , Tappin S. J. , Mizuno D. R. , Johnston J. C.
Published: May 2006

The Solar Mass Ejection Imager (SMEI) has been tracking coronal mass ejections (CMEs) from the Sun to the Earth and beyond since it came online in February 2003. This paper presents some results from the first 19 months of data from SMEI, when over 140 transients of many kinds were observed in SMEI's all‐sky cameras. We focus specifically on 20 earthward directed transients, and compare distance‐time plots obtained from the SMEI transients with those observed in halo CMEs by Large‐Angle Spectrometric Coronograph (LASCO) aboard Solar and Heliospheric Observatory (SOHO), and the arrival time of the shock observed by ACE at 0.99 AU. The geometry of one particular transient is compared using both LASCO and SMEI images in a first attempt to investigate geometry evolution as the transient propagates through the interplanetary medium. For some events, the halo CME, SMEI transient, and shock at 0.99 AU do not match, suggesting that some transients may not correspond to a halo CME. Finally, an evaluation of the potential of SMEI to be used as a predictor of space weather is presented, by comparing the transients observed in SMEI with the 22 geomagnetic storms which occurred during this timeframe. A transient was observed in 14 cases, and distance‐time profiles would have allowed a prediction of the arrival time at ACE within 2 hours of its actual arrival for three events, and within 10 hours for eight events. Of these eight events, seven were detected by SMEI more than 1 day before the transient's arrival at the Earth.
Dynamic geomagnetic rigidity cutoff variations during a solar proton event
Authors: Rodger Craig J. , Clilverd Mark A. , Verronen Pekka T. , Ulich Thomas , Jarvis Martin J. , Turunen Esa
Published: May 2006

Solar proton events (SPE) are major, though infrequent, space weather phenomena that can produce hazardous effects in the near‐Earth space environment. A detailed understanding of their effects depends upon knowledge of the dynamic rigidity cutoffs imposed by the changing total magnetic field. For the first time we investigate detailed comparisons between theoretical cutoff rigidities and ground‐based measurements during the large geomagnetic disturbance of 4–10 November 2001. We make use of the imaging riometer (IRIS) at Halley, Antarctica, fortunately situated such that the rigidity cutoff sweeps back and forth across the instrument's field of view during the SPE period. The Kp‐dependent geomagnetic rigidity cutoff energies are determined from satellite observations combined with previously reported particle‐tracing results. We find that the predicted absorption levels show good agreement with those experimentally observed for low and middle levels of geomagnetic disturbance (Kp < 5). However, during more disturbed geomagnetic conditions the cutoff modeling overestimates the stretching of the geomagnetic field, underestimating the rigidity cutoff energies, and hence leading to riometer absorption predictions that are too high. In very disturbed conditions (Kp ≈ 7–9) the rigidity energy cutoffs indicated by the IRIS observations appear to be equivalent to those predicted for Kp ≈ 6 by the particle‐tracing approach. Examples of changing rigidity cutoff contours for increasing levels of geomagnetic disturbance are presented.
Estimating relativistic electron pitch angle scattering rates using properties of the electromagnetic ion cyclotron wave spectrum
Authors: Loto'aniu T. M. , Thorne R. M. , Fraser B. J. , Summers D.
Published: May 2006

An EMIC wave event observed by the CRRES spacecraft during an active period on 11 August 1991 was studied in order to estimate electron minimum interaction kinetic energy Emin and using quasilinear theory, to calculate the resonant scattering rate Dαα. The wave packet semibandwidth δω/2π full‐width half maximum ranged from 0.06 Hz to 0.27 Hz. Resonant scattering was assumed to occur over the frequency interval ωm − δω to ωm + δω. Assuming typical stormtime ion concentrations, the use of realistic wave spectral properties when compared to only using the central wave frequency ωm results in 3 to 4 times as many wave packets that are able to interact with relativistic electrons below ∼2 MeV. Values of Dαα associated with two of the wave packets, where Emin falls to within the 1–2 MeV energy range, were comparable to the limit of strong diffusion suggesting enhanced electron precipitation. CRRES observed an ∼1 order of magnitude decrease in the 1–2 MeV electron flux levels during the EMIC wave interval. It is suggested that this flux decrease was due to EMIC waves pitch angle scattering the relativistic electrons. The EMIC waves were observed near the start of the main phase of a geomagnetic storm. This study strengthens the suggestion that relativistic electron scattering by EMIC waves can compete with the Dst effect as a mechanism of decreasing relativistic electron fluxes from the outer zone during magnetic storms.
Interannual variability of Tehuantepec eddies
Authors: Zamudio Luis , Hurlburt Harley E. , Metzger E. Joseph , Morey Steven L. , O'Brien James J. , Tilburg Charles , Zavala‐Hidalgo Jorge
Published: May 2006

TOPEX/Poseidon satellite altimeter observations and the Naval Research Laboratory Layered Ocean Model simulations show interannual variability in the number and intensity of Tehuantepec eddies off the Mexican southwest coast. Analysis of the results illustrates that downwelling coastally trapped waves, which are generated in the equatorial Pacific, play a crucial role in the modulation and generation of Tehuantepec eddies and a dominant role in Tehuantepec eddy interannual variability. This introduces a new paradigm in which the generation and modulation of Tehuantepec eddies is not exclusively explained in terms of the strong and intermittent Tehuantepec wind events. In fact, the results show anticyclonic eddy formation during periods of calm Tehuantepec winds. That is specifically exemplified by the formation of two anticyclonic Tehuantepec eddies during a 5‐month period of weak Gulf of Tehuantepec winds during summer of 1997. Furthermore, the satellite‐observed and NLOM‐simulated proliferation of Tehuantepec eddies during El Niño years is explained by the corresponding increase in downwelling coastally trapped waves and a lack of increase in the number and strength of Tehuantepec wind events during El Niño years.
Global impact of road traffic on atmospheric chemical composition and on ozone climate forcing
Authors: Niemeier Ulrike , Granier Claire , Kornblueh Luis , Walters Stacy , Brasseur Guy P.
Published: May 2006

Automobile emissions are known to contribute to local air pollution and to photochemical smog in urban areas. The impact of road traffic on the chemical composition of the troposphere at the global scale and on climate forcing is less well quantified. Calculations performed with the chemical transport MOZART‐2 model show that the concentrations of ozone and its precursors (NOx, CO, and hydrocarbons) are considerably enhanced in most regions of the Northern Hemisphere in response to current surface traffic. During summertime in the Northern Hemisphere, road traffic has increased the zonally averaged ozone concentration by more than 10% in the boundary layer and in the extratropics by approximately 6% at 500 hPa and 2.5% at 300 hPa. The summertime surface ozone concentrations have increased by typically 1–5 ppbv in the remote regions and by 5–20 ppbv in industrialized regions of the Northern Hemisphere. The corresponding ozone‐related radiative forcing is 0.05 Wm−2. In order to assess the sensitivity of potential changes in road traffic intensity, two additional model cases were considered, in which traffic‐related emissions in all regions of the world were assumed to be on a per capita basis the same as in Europe and in the United States, respectively. In the second and most dramatic case, the surface ozone concentration increases by 30–50 ppbv (50–100%) in south Asia as compared to the present situation. Under this assumption, the global radiative forcing due to traffic‐generated ozone reaches 0.27 Wm−2.
Decision theory and the analysis of rare event space weather forecasts
Authors: Weigel R. S. , Detman T. , Rigler E. J. , Baker D. N.
Published: May 2006

Several basic results from decision theory as applied to rare event forecasts are reviewed, and an alternative method for comparing rare event forecasts is presented. A fundamental result is that for a large class of users only interested in economic utility, the relevant performance quantity is the number of correct and false alarm forecasts. This is contrasted with the reality that most forecast models are optimized to have a high data‐model correlation, which does not always correspond to maximum economic utility. The value score (VS) developed by Wilks (2001) partially resolves this disconnect between modeler‐ and user‐relevant metrics. Although the value score is closer to what is most likely of interest to a user, maximal VS does not necessarily correspond to maximal utility for the realistic case where the cost and benefit are dependent on the amplitude of the forecasted event. An alternative comparison and presentation method is proposed which may resolve this problem. For the class of users considered, full specification of model performance requires computation of the probability of correct, false alarm, and missed forecasts at several amplitude levels and warning time spans. Examples of the computations involved for the modeler and user are given for predictions of large‐amplitude energetic electron fluence and geomagnetic storms parameterized by the Dst index.
An analog forecast model for the high‐latitude ionospheric potential based on assimilative mapping of ionospheric electrodynamics archives
Authors: Kihn E. A. , Zhizhin M. , Kamide Y.
Published: May 2006

We review an emerging technique for ionospheric forecast whereby empirical models and data assimilation techniques are combined and show that the blended technique produces a diminished result compared to using the empirical models alone. We then present a technique for the nowcast/forecast of ionospheric potential patterns using an analog forecast technique. This is a new type of model for describing ionospheric potential patterns based on matching solar wind conditions and available ground observations to previously archived assimilative mapping of ionospheric electrodynamics (AMIE) runs. The model combines the best features of a data assimilation–based model with the availability and forecast potential of an empirically based model. We define a set of comparison metrics, show quantitatively how this model compares with the Weimer (1996) model and detail the performance for a May 1998 event.
Active tectonics in Eastern Lunana (NW Bhutan): Implications for the seismic and glacial hazard potential of the Bhutan Himalaya
Authors: Meyer M. C. , Wiesmayr G. , Brauner M. , Häusler H. , Wangda D.
Published: May 2006

Paleoseismological investigations, brittle fault analysis, and paleostrain calculations combined with the interpretation of satellite imagery and flood wave modeling were used to investigate the seismic and associated glacial hazard potential in Eastern Lunana, a remote area in NW Bhutan. Seismically induced liquefaction features, cracked pebbles, and a surface rupture of about 6.8 km length constrain the occurrence ofM≥ 6 earthquakes within this high‐altitude periglacial environment, which are the strongest earthquakes ever been reported for the Kingdom of Bhutan. Seismicity occurs along conjugate sets of faults trending NE‐SW to NNW‐SSE by strike‐slip and normal faulting mechanism indicating E‐W extension and N‐S shortening. The strain field for these conjugate sets of active faults is consistent with widespread observations of young E‐W expansion throughout southern Tibet and the north Himalaya. We expect, however, that N‐S trending active strike‐slip faults may even reach much farther to the south, at least into southern Bhutan. Numerous glacial lakes exist in the investigation area, and today more than 100 × 106m3of water are stored in moraine‐dammed and supraglacial lakes which are crosscut by active faults. Strong earthquakes may trigger glacial lake outburst floods, and the impact of such flash floods may be worst 80 km downstream where the valley is broad and densely populated. Consequently, tectonic models of active deformation have to be closely linked with glacial hazard evaluation and require rethinking and modification.
Optimal groundwater remediation design using an Adaptive Neural Network Genetic Algorithm
Authors: Yan Shengquan , Minsker Barbara
Published: May 2006

Large‐scale water resources optimization often involves using time‐consuming simulation models to evaluate potential water resource designs or calibrate parameter values. Approximation models have been proposed for improving computational efficiency of the optimization. In most instances, multiple simulation runs have been done prior to the optimization, which are then used to fit an approximate model that is used during the optimization. This paper demonstrates that this approach can lead to suboptimal solutions and proposes a dynamic modeling approach, called Adaptive Neural Network Genetic Algorithm (ANGA), in which artificial neural networks are adaptively and automatically trained directly within a genetic algorithm (GA) to replace the time‐consuming water resource simulation models. A dynamic learning approach is proposed to periodically sample new solutions both to update the ANNs and to correct the GA's convergence. Different configurations of ANGA were tested on a hypothetical groundwater remediation design case, and then the best configuration was applied to a field‐scale case. In these applications, ANGA saved 85–90% percent of the simulation model calls with no loss in accuracy of the optimal solutions. These results show that the method has substantial promise for reducing computational effort associated with large‐scale water resources optimization.
Study of electronic and spectroscopic properties on a newly synthesized red fluorescent material
Authors: Liu Xiaojun , Ju Haidong , Zhao Xian , Tao Xutang , Bian Wensheng , Jiang Minhua
Published: May 2006

The ground state (S0) and the lowest singlet excited state (S1) of a newly synthesized red fluorescent material, 2-[3-(2-{4-[(2-Hydroxy-ethyl)-methyl-amino]-phenyl}-vinyl)-5,5-dimethyl-cyclohex-2-enylidene]-malononitrile (A31), are investigated. The S0 and S1 geometries are optimized at the ab initio Hartree-Fock and the singles configuration interaction (CIS) levels of theory, respectively. The CIS and semiempirical Zerner's Intermediate Neglect of Differential Overlap (ZINDO) methods provide the results for the absorption (S0→S1) and emission (S1→S0) transition energies. The Stokes shifts calculated at the CIS and ZINDO levels of theory are obtained. The absorption spectra in various solvents are calculated using the time-dependent density-functional theory method in combination with the polarized continuum model, which are in very good agreement with our experimental measurements. The solvent effects are discussed.
Vibrational and electron paramagnetic resonance properties of free and MgO supported AuCO complexes
Authors: Giordano Livia , Carrasco Javier , Di Valentin Cristiana , Illas Francesc , Pacchioni Gianfranco
Published: May 2006

The bonding, spin density related properties, and vibrational frequency of CO bound to single Au atom in the gas-phase or supported on MgO surfaces have been investigated with a variety of computational methods and models: periodic plane waves calculations have been compared with molecular approaches based on atomic orbital basis sets; pseudopotential methods with all electron fully relativistic calculations; various density functional theory (DFT) exchange-correlation functionals with the unrestricted coupled-cluster singles and doubles with perturbative connected triples [CCSD(T)]. AuCO is a bent molecule but the potential for bending is very soft, and small changes in the bond angle result in large changes in the CO gas-phase vibrational frequency. At the equilibrium geometry the DFT calculated vibrational shift of CO with respect to the free molecule is about −150cm−1, whereas smaller values −60∕−70cm−1 are predicted by the more accurate CCSD(T) method. These relatively large differences are due to the weak and nonclassic bonding in this complex. Upon adsorption on MgO, the CO vibrational shift becomes much larger, about −290cm−1, due to charge transfer from the basic surface oxide anion to AuCO. This large redshift is predicted by all methods, and is fully consistent with that measured for MgO∕AuCO complexes. The strong influence of the support on the AuCO bonding is equally well described by all different approaches.