bluuebunny/crossref_metadata_2025 huggingface dataset:
A proposal of a 3.3‐kV/6.6‐kV transformerless hybrid filter, and experimental verification based on a 200‐V laboratory system
Authors: Srianthumrong Sunt , Tamai Yasuhiro , Akagi Hirofumi
Published: November 2003

This paper proposes a transformerless shunt hybrid filter for harmonic compensation of a three‐phase six‐pulse diode rectifier, where the AC line‐to‐line voltage is 3.3 or 6.6 kV. The hybrid filter consists of a single tuned LC filter per phase and an active filter with a DC capacitor voltage as low as 300 or 600 V. The two filters are directly connected in series with each other without a transformer. The passive filter absorbs harmonic currents produced by the rectifier, whereas the active filter improves the filtering characteristics of the passive filter. The required rating of the active filter is much smaller than that of a conventional shunt active filter used alone. Another advantage is that no additional switching‐ripple filter is required for the active filter because the LC filter acts not only as a tuned LC filter around the seventh‐harmonic frequency but also as a switching‐ripple filter around 10 kHz. A feedforward control scheme is also proposed to improve the active filter performance. Experimental results obtained from a 200‐V, 5‐kW laboratory system and simulation results of a 3.3‐kV, 300‐kW system confirm the validity and effectiveness of the system. The hybrid filter gives satisfactory compensation performance, thus allowing us to put it into practical use. © 2003 Wiley Periodicals, Inc. Electr Eng Jpn, 146(2): 54–65, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10236
Insulation characteristics of GIS under nonstandard lightning impulse oscillations: Insulation characteristics under double‐frequency oscillations with various frequencies and damping ratios
Authors: Yuasa Sadayuki , Kato Keiichi , Okabe Shigemitsu
Published: November 2003

To improve GIS insulation specifications, it is important to recognize the insulation characteristics under oscillatory overvoltage waveforms occurring in the field. This paper describes investigations of insulation characteristics for double‐frequency oscillatory waveforms with various frequencies and damping ratios. It was found that minimum breakdown voltages (Vmin) were irrelevant to frequency changes in the range of experimental conditions under the same damping conditions. On the other hand, Vmin rose with the damping ratio rising under the same frequency conditions. The insulation characteristics at a valley of oscillation were investigated using actual breakdown voltages. It was found that the insulation characteristics were treated all‐inclusively based on the characteristics of Vmin for damping time. © 2003 Wiley Periodicals, Inc. Electr Eng Jpn, 146(2): 11–19, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10245
Characteristics of creeping discharge developed in a narrow gap between insulators and effect of a backside electrode
Authors: Nishikawa Tetsuji , Sakamoto Naoki , Ueno Hideki , Nakayama Hiroshi
Published: November 2003

Discharge characteristics have been investigated for a needle–plane electrode configuration containing insulating barriers with a narrow gap which has been placed between the needle and the plane. The characteristics of creeping discharge developed in the narrow gap of the barrier filled with SF6 are especially considered. In the case of a configuration with a backside electrode below the needle, the corona generated from the needle easily extended to the gap. On the other hand, for a configuration without a backside electrode, the corona has hardly extended to the gap, and on increasing the applied voltage the corona developed greatly in the gap. This difference in corona extension should affect the flashover characteristics in the present system. © 2003 Wiley Periodicals, Inc. Electr Eng Jpn, 146(2): 27–36, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10248
Improvement of microwave power from a virtual cathode oscillator and its repetitive operation using a metal mesh anode
Authors: Onoi Masahiro , Yamabuchi Masahiko , Yatsuzuka Mitsuyasu
Published: November 2003

A virtual cathode oscillator with a stainless‐steel mesh anode of various transparencies and wire diameters was studied experimentally for the enhancement of microwave power and its repetitive operations. The maximum microwave power observed was about 20 MW at 12 GHz for a diode voltage of 250 kV and an electron beam current of 39 kA using an anode mesh with wire diameter of 0.22 mm and a transparency of 67%. The microwave emission was enhanced by decreasing the mean angle of beam scattering when a mesh of smaller wire diameters was used in the anode. The increased transparency of the fine mesh also contributed to the enhancement of the microwave emission. Use of the mesh anode afforded the operation in several repetitive shots. © 2003 Wiley Periodicals, Inc. Electr Eng Jpn, 146(2): 1–10, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10259
Molecular dynamics in the formation process of single‐walled carbon nanotubes
Authors: Shibuta Yasushi , Maruyama Shigeo
Published: November 2003

The mechanism of the nucleation and formation of single‐walled carbon nanotubes (SWNTs) was investigated using molecular dynamics simulations. When the initial state was chosen so that carbon and nickel atoms were randomly distributed in a simulation domain, the formation of a random cage structure made up of carbon atoms, which had a few nickel atoms inside it, was observed by 6 ns. The nickel atoms, which move inside or on the surface of the cage, were seen to be preventing the complete closure of the cage and its anneal into the fullerene structure. Further, in order to observe a longer time‐scale growth process, the simulation cell was artificially shrunk by the progress of simulation so that collisions between precursor clusters were promoted to comply with the limitation in the calculation time. Collisions of the imperfect random‐cage clusters led to an elongated tubular cage structure, which could be regarded as an initiation of SWNTs. The simulation results were compared with FT‐ICR mass spectra of the positive clusters generated by a laser‐vaporization supersonic‐expansion cluster beam source. © 2003 Wiley Periodicals, Inc. Heat Trans Asian Res, 32(8): 690–699, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.10123
Bubble behavior in vertical tube banks installed in a fluidized bed
Authors: Furui Shuji , Umekawa Hisashi , Hayashi Kouichi , Ozawa Mamoru , Takenaka Nobuyuki
Published: November 2003

Fluidized bed combustion is one of the advantageous technologies for coal and/or incineration firing especially with respect to the environmental protection of emissions, such as NOx/SOx. Bed material movement in such a fluidized bed has a prime importance in the heat transfer process. Thus, quantitative measurement of the bed material movement and the void fraction are indispensable for better understanding of the fluidized bed. In this investigation, neutron radiography is applied to visualize the bed material movement in a simulated fluidized bed heat exchanger installed with vertical tubes. Bubble behavior and void fraction profile are obtained by the image processing technique. Bubble movement is highly restrained by these vertical tubes, so that the bubbles rise up along the tube. The bubble diameter is well correlated by the modified Mori and Wen's correlation taking into account the pitch of the tube arrangement. The bubble rise velocity and void fraction are well correlated by applying the drift‐flux model. © 2003 Wiley Periodicals, Inc. Heat Trans Asian Res, 32(8): 727–739, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.10127
Rate constants for the gas‐phase reaction of CF3CF2CF2CF2CF2CHF2 with OH radicals at 250–430 K
Authors: Chen L. , Tokuhashi K. , Kutsuna S. , Sekiya A.
Published: November 2003

The rate constants k1 for the reaction of CF3CF2CF2CF2CF2CHF2 with OH radicals were determined by using both absolute and relative rate methods. The absolute rate constants were measured at 250–430 K using the flash photolysis–laser‐induced fluorescence (FP‐LIF) technique and the laser photolysis–laser‐induced fluorescence (LP‐LIF) technique to monitor the OH radical concentration. The relative rate constants were measured at 253–328 K in an 11.5‐dm3 reaction chamber with either CHF2Cl or CH2FCF3 as a reference compound. OH radicals were produced by UV photolysis of an O3–H2O–He mixture at an initial pressure of 200 Torr. Ozone was continuously introduced into the reaction chamber during the UV irradiation. The k1 (298 K) values determined by the absolute method were (1.69 ± 0.07) × 10−15 cm3 molecule−1 s−1 (FP‐LIF method) and (1.72 ± 0.07) × 10−15 cm3 molecule−1 s−1 (LP‐LIF method), whereas the K1 (298 K) values determined by the relative method were (1.87 ± 0.11) × 10−15 cm3 molecule−1 s−1 (CHF2Cl reference) and (2.12 ± 0.11) × 10−15 cm3 molecule−1 s−1 (CH2FCF3 reference). These data are in agreement with each other within the estimated experimental uncertainties. The Arrhenius rate constant determined from the kinetic data was K1 = (4.71 ± 0.94) × 10−13 exp[−(1630 ± 80)/T] cm3 molecule−1 s−1. Using kinetic data for the reaction of tropospheric CH3CCl3 with OH radicals [k1 (272 K) = 6.0 × 10−15 cm3 molecule−1 s−1, tropospheric lifetime of CH3CCl3 = 6.0 years], we estimated the tropospheric lifetime of CF3CF2CF2CF2CF2CHF2 through reaction with OH radicals to be 31 years. © 2003 Wiley Periodicals, Inc. Int J Chem Kinet 36: 26–33, 2004
Deductive molecular mechanics of sp3 carbon atom
Authors: Tchougréeff A. L. , Tokmachev A. M.
Published: November 2003

The problem of substantiation of additive systematics such as molecular mechanics is considered. Antisymmetrized product of strictly localized geminals (APSLG) trial wavefunction is used as a starting point for this substantiation. The main force fields of molecular mechanics—those of bonding and bending—are derived for sp3 carbon from the analysis of the total energy in semiempirical variant of the APSLG scheme. Analytically obtained constants of these force fields are in perfect coincidence with those typically used in the empirical force fields. The formulae for off‐diagonal force fields are also obtained and analyzed. The application of the results for understanding the organic stereochemistry is discussed. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem, 2004
DFT study of the role of intermolecular interactions in the formation of stable halogeno– and ammineaqua– platinum(II) coordination compounds
Authors: Panina Natalia S. , Beljaev Alexander N. , Simanova Svetlana A. , Calligaris Mario
Published: November 2003

Density functional theory (DFT) and Hartree–Fock (HF) methods have been used to calculate the electronic and geometric structures of cis‐ and trans‐[Pt(NH3)2X2] (X = Cl−, Br−, I−), [cis‐Pt(NH3)2(H2O)2]2+ and its deprotonated forms. The thermodynamic parameters ΔH, ΔS, ΔG, and ΔCp = f(T) have been obtained from DFT force fields and normal mode frequencies. It is shown that the greater stability of the trans‐isomers is due, at the molecular level, to different interligand interactions. The stability of the cis‐isomers is significantly increased by intermolecular Pt…Pt and NH2‐H…X nonvalence interactions between mononuclear [cis‐Pt(NH3)2X2] moieties, the effect reducing in the row Cl− > Br− > I−. The thermodynamic parameters of possible phases of the hydrolysis of [cis‐Pt(NH3)2(H2O)2]2+ have been also derived. Solvent effects have been investigated calculating the equilibrium constants for the proton transfer reactions both in gas phase and water solution. It is shown that in aqueous medium the hydroxobridged platinum dimer [Pt(NH3)2‐ (μ‐OH)], characterized by a Pt…Pt distance of 3.119 Å, is the preferred hydrolysis product. It is also shown that with short metal–metal interactions, such as those found in [cis‐Pt(NH3)2Cl2] and [cis‐Pt(NH3)2(H2O)2]2+, the conditions for the formation of linear polynuclear complexes with PtPt bonds (the so‐called “platinum blues”) are created. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem, 2004
Excited states of transition metal compounds: Quantum chemistry of relaxation effects
Authors: Baranovski V. I. , Lubimova O. O.
Published: November 2003

The electronic excitation of coordination compounds is followed by a number of relaxation effects (geometry changes, emission, nonradiative transitions, electron transfer). This article concerns the possible ways to use the standard methods of modern quantum chemistry in conjunction with the time‐dependent formalism (wave packets dynamics) to study these effects in the metal‐to‐ligand charge transfer (MLCT) excited states. The first example concerns the estimation of the geometry changes in organic ligands due to the electronic excitation. The second example concerns the prediction of the trends in the constants of nonradiative transitions. The results of the calculations for several sets of Ru(II) and Os(II) complexes with 2,2′‐bipyridine and its derivatives are in good agreement with experiment. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem, 2004
Competing after radical technological change: the significance of product line management strategy
Authors: Jones Neil
Published: November 2003

Research on firm performance after the introduction of a radical technological change has primarily concerned itself with differences between incumbents and entrants. This paper explores other factors that may influence firm performance over the longer term after a radical change—specifically, those related to product line management strategy. Following a radical change, a period of incremental technological change typically creates the opportunity for rapid development of new products. In such settings, strategies to manage multiple products, including families of related products that can be derived from a common platform, may be expected to impact competitive performance, especially over the longer term. The data for the study are from the telecommunications switching sector, specifically the private branch exchange (PBX) industry. Fifty‐six firms and over 240 new products were analyzed over 22 years. This study shows that incumbent–entrant‐based explanations of firm performance are incomplete. In particular, the results demonstrate that product line strategy explains significant additional variation in firm performance. The paper tests hypotheses linking both overall product line strategy and product platform strategy to firm performance. It finds that overall product introduction rates and product longevity can be linked to performance. It also shows that decomposing overall strategy into product platform strategy—rates of platform and derivative introduction, and platform longevity—can further increase explanatory power. In total, the results indicate that strategic prescriptions in the literature that emphasize development speed alone are oversimplified. They also suggest that differences in how relationships among products derived from a common platform are managed can contribute to competitive advantage and demand complex trade‐offs. Copyright © 2003 John Wiley & Sons, Ltd.
Structure‐function relationships of hirulog peptide interactions with thrombin
Authors: Bourdon Paul , Jablonski Jo-Ann , Chao Betty H. , Maraganore John M.
Published: November 2003

Using hirudin as a model, a novel class of bivalent thrombin inhibitors has been designed and characterized (Maraganore et al. (1990) Biochemistry 29, 7095–7101). These peptides, designated ‘hirulogs’, interact with both thrombin's catalytic center and its anion‐binding exosite for fibrinogen recognition. In order to investigate structure‐activity relationships in hirulog peptides, a number of peptide and peptidomimetic derivatives with alterations in catalytic‐site binding and anion‐binding exosite binding moieties were prepared. Replacements or modifications in the catalytic site and exosite binding moieties were achieved with the consequences of maintaining or improving antithrombin activity. In addition to showing improved affinity for thrombin, some derivatives with K
1's in the sub‐nanomolar range showed increased anticoagulant activities. These findings highlight the versatility of hirulog peptides in their bivalent interactions with thrombin.
Determination of the amino acid sequence of an intramolecular disulfide linkage‐containing sperm‐activating peptide by tandem mass spectrometry
Authors: Yoshino Ken-ichi , Takao Toshifumi , Shimonishi Yasutsugu , Suzuki Norio
Published: November 2003

A sperm‐activating peptide (SAP) was isolated from the egg jelly of the sea urchin Stomopneustes variolaris. The presence of an intramolecular disulfide linkage in the peptide was demonstrated by fast atom bombardment (FAB) mass spectrometry with the intact and reduced peptides. The amino acid sequence of the reduced peptide was determined to be Lys‐Phe‐Cys‐Pro‐Glu‐Gly‐Lys‐Cys‐Val by tandem mass spectrometry from the spectrum produced by a collision‐induced decomposition method. Furthermore, it was also demonstrated that SAPs obtained from sea urchins Arbacia punctulata and Glyptpcidaris crenularis are cyclic peptides containing one cystine residue by FAB mass spectrometry.
Interaction of adenine nucleotides with the adenine nucleotide translocase regulates the developmental changes in proton conductance of the inner mitochondrial membrane
Authors: Valcarce Carmen , Vuezva JoséM.
Published: November 2003

2‐h‐old neonatal liver mitochondria, when depleted of adenine nucleotides, showed an ‘ohmic’ current‐voltage relationship and a higher passive proton permeability of the membrane, resembling fetal mitochondrial behaviors for the proton conductance. Incubation of fetal mitochondria with ATP, GDP or carboxyatractyloside promoted a significant reduction in the passive proton permeability of the membrane and the appearance of the characteristic biphasic behavior for the proton conductance. It is concluded that the postnatal increase in intramitochondrial adenine nucleotide concentration promotes, by the interaction of the nucleotides with the adenine nucleotide translocase, the reduction in the passive proton permeability of the mitochondrial membrane, allowing efficient energy conservation in the neonatal liver.
Eicosanoid generation from antigen‐primed mast cells by extracellular mammalian 14‐kDa group II phospholipase A2
Authors: Murakami Makoto , Kudo Ichiro , Inoue Keizo
Published: November 2003

The extracellular form of 14‐kDa group II phospholipase A2 has been found to accumulate at various types of inflammatory sites. In the present paper, we have studied the possible role of the extracellular 14‐kDa group II phospholipase A2 in the process of prostaglandin production in activated rat mast cells. When mast cells obtained from the peritoneal cavity of rats were sensitized with IgE, challenged with antigen and then exposed to extracellular 14‐kDa group II phospholipase A2, appreciable release of prostaglandin D2 was observed. Generation of prostaglandin D2 was dependent on the concentration of the phospholipase A2 as well as that of the antigen, while no appreciable prostaglandin D2 generation was observed with cells in the absence of the antigen. No histamine release was observed under the same conditions. Phosphatidylcholine in mast cell membranes was appreciably hydrolyzed to liberate free arachidonic acid when mast cells were incubated with 14‐kDa group II phospholipase A2 added exogenously in the presence of the antigen. Both the generation of prostaglandin D2 and the release of arachidonic acid were retarded by inhibitors specific to 14‐kDa group II phospholipase A2. Thus, 14‐kDa group II phospholipase A2 may function in the process of inflammation by acting on IgE‐antigen‐primed mast cells, which are not fully activated, to generate eicosanoids.
Protein kinase C in rat brain synaptosomes
Authors: Tanaka Shin-ichiro , Tominaga Masahiro , Yasuda Ichiro , Kishimoto Akira , Nishizuka Yasutomi
Published: November 2003

A small fraction (approximately 5%) of protein kinase C (PKC) in the adult rat brain synaptosomes is tightly associated with Triton X‐100‐insoluble components (most likely membrane‐skeleton elements), and is solubilized only after denaturation with sodium dodecyl sulfate. The kinase domain of this PKC can be released as a soluble form after limited proteolysis with calpain, whereas the regulatory domain which binds phorbol ester remains insoluble. The PKC in this fraction was identified as the βII‐subspecies or its related molecule. Presumably, this enzyme subspecies is responsible for the phosphorylation of a major PKC substrate protein, growth‐associated protein‐43, which is located in nerve endings as well as in growth cones in association with the membrane‐skeleton elements.
Matrix degrading properties of sperm serine proteinase, acrosin
Authors: Planchenault T. , Čechová D. , Keil-Dlouha V.
Published: November 2003

The serine proteinase acrosin plays an important role in sperm penetration of the zona pellucida. In the present study we investigated the effect of the enzyme on various matrix proteins. Acrosin degraded proteolytically fibronectin, type IV collagen and heat denatured type I collagen, whereas neither native type I collagen nor laminin were cleaved by the enzyme. The specific activity of acrosin with type IV collagen as substrate (66.6 g/h/g) was 125‐fold higher than that of known type IV collagenase or stromelysin. These results suggest that acrosin may act as a matrix‐degrading proteinase.
Feline lower airway disease: A retrospective study of 22 naturally occurring cases from Greece
Authors: Adamama-Moraitou K.K. , Patsikas M.N. , Koutinas A.F.
Published: November 2003

In this retrospective study of 22 cats with lower airway disease of either intermittent (23%) or persistent nature (77%), the Siamese breed (55%) was significantly over-represented. Females (68%) were slightly but not significantly over-represented. No significant association was found between the clinical stage of disease and the physical findings, thoracic radiographic changes or the response to treatment. Cough, the most common presenting complaint, was the only symptom detected in the cats with intermittent disease, yet the two most severely affected animals did not show it. Thoracic auscultation did not reveal any abnormality in 41% of the cats. Haematology revealed eosinophilia in 46% of the cats. A bronchial pattern was the most common radiographic abnormality (73%), followed by alveolar (32%) and interstitial patterns (23%). Interestingly, thoracic radiographs were normal in 23% of the cats. The combination of short-term corticosteroids and bronchodilators resulted in complete and long-term remission of symptoms in nine cats, while the other 11 required ongoing medication because of relatively frequent relapses. One of the remaining two cats died during an asthmatic crisis, while the other was lost to follow up.
Outer membrane protein A of Escherichia coli forms temperature‐sensitive channels in planar lipid bilayers
Authors: Zakharian E , Reusch R.N
Published: November 2003

The temperature dependence of single‐channel conductance and open probability for outer membrane protein A (OmpA) of Escherichia coli were examined in planar lipid bilayers. OmpA formed two interconvertible conductance states, small channels, 36–140 pS, between 15 and 37°C, and large channels, 115–373 pS, between 21 and 39°C. Increasing temperatures had strong effects on open probabilities and on the ratio of large to small channels, particularly between 22 and 34°C, which effected sharp increases in average conductance. The data infer that OmpA is a flexible temperature‐sensitive protein that exists as a small pore structure at lower temperatures, but refolds into a large pore at higher temperatures.
Reversible pulmonary hypertension in heart transplant candidates—pretransplant evaluation and outcome after orthotopic heart transplantation
Authors: Klotz Stefan , Deng Mario C. , Hanafy Dudy , Schmid Christof , Stypmann Jörg , Schmidt Christoph , Hammel Dieter , Scheld Hans H.
Published: November 2003

Background:

Heart transplantation is the most effective treatment for well‐selected patients with endstage heart failure. Unfortunately, transplant candidates with pulmonary hypertension (PHT) are often not considered for heart transplantation. This study was performed to assess the value of prostaglandin E1 (PG‐E1) for reduction of PHT and to predict the postoperative outcome, compared to patients without PHT.

Patients and methods:

We studied a group of 151 consecutive heart transplant candidates using right heart catheterization. In patients with PHT (pulmonary vascular resistance, PVR≥2.5 Wood‐Units (WU) and/or transpulmonary gradient (TPG)≥12 mmHg) a short‐term treatment protocol with PG‐E1 was performed, to achieve PVR<2.5 WU and TPG<12 mmHg.

Results:

61 patients (40%) had PHT according to our criteria. Reduction of PHT was successful in 71% of patients (n=43), of these, 18 patients underwent cardiac transplantation and the 1‐year mortality rate was 22% (n=4). The 1‐year mortality rate in transplanted patients without PHT was 14% (n=3). There was no statistical difference in survival between the PHT and the non‐PHT group. Outcome in patients without heart transplantation was similar in both groups, except for patients with non‐reducible PHT (1‐year mortality 50%).

Conclusions:

Our study demonstrates the efficacy and safety of PG‐E1 in lowering PHT in heart transplant candidates, as well as the need for aggressive evaluation and treatment in these patients. Patients with reversible PHT have comparable post‐transplant outcomes and no tendency to higher acute right ventricular failure.
Nitric oxide exhalation correlates with ventilatory response to exercise in patients with heart disease
Authors: Adachi Hitoshi , Oshima Shigeru , Sakurai Shigeki , Toyama Takuji , Hoshizaki Hiroshi , Taniguchi Koichi , Ito Haruki
Published: November 2003

Aims:

It is controversial whether or not pulmonary nitric oxide (NO) production, reflected in the end‐tidal alveolar NO concentration, is diminished in patients with heart failure. Since pulmonary perfusion is regulated by NO production, decreased NO production in the pulmonary vasculature is assumed to result in diminished lung perfusion and further increases in ventilation–perfusion mismatch. The aim of this study is to investigate whether exhaled NO correlates with both exercise‐induced hyperpnea and exercise tolerance in patients with heart disease.

Methods and Results:

Forty‐two patients with heart disease were enrolled (history of prior myocardial infarction (n=19), dilated cardiomyopathy (n=2), hypertensive heart disease (n=5) and prior open‐heart surgery (n=16)). During cardiopulmonary exercise testing, exhaled air was collected and end‐tidal NO (ETNO) was measured using a chemiluminescent method. Peak ETNO was found to correlate positively with both ventilatory anaerobic threshold (r=0.468) and peak VO2 (r=0.562). The VE‐CO2 slope, which reflects the ventilatory response to exercise, correlated negatively with peak ETNO (r=−0.588).

Conclusion:

These data indicate that NO exhalation correlates, inversely, with the ventilatory response to exercise and directly with exercise intolerance, although the weakness of the correlation coefficient suggests there may be other possible mechanisms.
A systematic review of telemonitoring for the management of heart failure
Authors: Louis Amala A. , Turner Tracy , Gretton Marcia , Baksh Angela , Cleland John G.F.
Published: November 2003

Background:

Telemonitoring allows a clinician to monitor, on a daily basis, physiological variables measured by patients at home. This provides a means to keep patients with heart failure under close supervision, which could reduce the rate of admission to hospital and accelerate discharge.

Objective:

To review the literature on the application of telemedicine in the management of heart failure.

Methods:

A literature search was conducted on studies involving telemonitoring and heart failure between 1966 and 2002 using Medline, Embase, Cochrane Library and Journal of Telemedicine and Telecare.

Results:

Eighteen observational studies and six randomised controlled trials involving telemonitoring and heart failure were identified. Observational studies suggest that telemonitoring; used either alone or as part of a multidisciplinary care program, reduce hospital bed‐days occupancy. Patient acceptance of and compliance with telemonitoring was high. Two randomised controlled trials suggest that telemonitoring of vital signs and symptoms facilitate early detection of deterioration and reduce readmission rates and length of hospital stay in patients with heart failure. One study also showed a reduction in readmission charges. One substantial randomised controlled study showed a significant reduction in mortality at 6 months by monitoring weight and symptoms in patients with heart failure; however, no difference was observed in readmission rates. Another randomised study comparing video‐consultation performed as part of a home health care programme for patients with a variety of diagnoses, suggested a reduction in the costs of hospital care, which offset the cost of video‐consultation. Patients with heart failure were not reported separately. One randomised study showed no difference in outcomes between the telemonitoring group and the standard care group.

Conclusion:

Telemonitoring might have an important role as part of a strategy for the delivery of effective health care for patients with heart failure. Adequately powered multicentre, randomised controlled trials are required to further evaluate the potential benefits and cost‐effectiveness of this intervention.
Ego-Shooter - Gewalthaltige Computerspiele und aggressive Neigungen
Authors: Frindte Wolfgang , Obwexer Irmgard
Published: November 2003

Zusammenfassung. Im vorliegenden Artikel werden zunächst exemplarisch der Forschungsstand zum Thema und ein von Anderson und Dill (2000) genutztes theoretisches Modell vorgestellt. Das Modell und die von den Autor/inn/en vorgelegten Befunde liefern die Grundlage für eine Studie, die im Rahmen eines größeren Forschungsvorhabens durchgeführt wurde. In einem Laborexperiment spielten 20 männliche Erwachsene ein gewalthaltiges und ein nichtgewalthaltiges Spiel. Die Befunde zeigen, dass das kurzfristige Spielen gewalthaltiger Computerspiele zu gesteigerter innerer Erregung (Erhöhung von Blutdruck- und Pulswerten) und zu erhöhten aktuellen aggressiven Neigungen nach dem Spiel führt. Dieser Effekt wird durch relativ stabile Persönlichkeitsdispositionen (gemessen an der Aggressionsbereitschaft) moderiert.
Thin layer tuned reflections from an anisotropic décollement zone
Authors: Peacock Sheila
Published: November 2003

The décollement beneath the Barbados accretionary complex is a gently dipping shear zone 10–40 m thick within which slippage occurs between the overlying sediments of the accretionary wedge and the underthrust sediments on the subducting tectonic plate. The density and seismic velocity of the décollement, derived from modeling of “tuned” seismic P wave reflections from its top and base, are very low and indicate high porosity sustained by above‐hydrostatic pore pressure. Previous modeling assumed that the décollement is isotropic. Here we investigate whether neglecting anisotropy might bias the interpretation. Likely causes of anisotropy are aligned cracks and aligned pores and grains within the clays. Unrecognized anisotropy might cause misestimation of porosity, and confusion of P – S – P mode converted waves with the tuned P wave reflections. Horizontal cracks within the décollement would cause lower vertical velocity than in an isotropic material with the same porosity; this reduces the interpreted porosity, but by only a few percent, because crack density is limited by the observed finite strength of the décollement. P – S – P mode‐converted waves would be caused by anisotropy due to nonhorizontal alignment within the décollement or in the accretionary wedge above. Appreciable P – S – P conversion requires anisotropy too great to be caused by aligned cracks alone. A décollement of aligned anisotropic clay particles gives appreciable mode conversion when 50% of the clay particles are within 30° of perfect alignment. Reflections for incidence angles up to ∼26° from a strongly anisotropic décollement zone with horizontal alignment are indistinguishable from those from an isotropic zone.
An analysis of the frequency and distribution of ducting events in simulated radio occultation measurements based on ECMWF fields
Authors: von Engeln Axel , Nedoluha Gerald , Teixeira João
Published: November 2003

A study of the occurrence of ducts valid at GPS frequencies in the European Center for Medium‐Range Weather Forecasts (ECMWF) atmospheric fields is presented. A radio occultation simulator has been applied to determine the mean location of the occultations for a 10 day period in May 2001. In total, 5348 occultations were found. Refractivity profiles have been calculated at the mean occultation location by extracting temperature and water vapor profiles from ECMWF data. The gradient of refractivity with respect to altitude was analyzed for ducting conditions, which occurs below about −160 km−1. About 10% of the simulated measurement profiles show ducts. Polar ducting events are mainly occurring over land, very close to the surface. Midlatitude ducting events are almost evenly distributed over land and sea, where land events are close to the surface too. Tropical ducting events are mainly located over the sea. Events over the sea show ducts within a vertical altitude interval of 0–2.5 km. Tropical events tend to occur at higher altitudes than midlatitudes ones do. The thickness of the layer over which ducting conditions occur increases with altitude and reaches about 120 m for higher altitudes. Near‐surface ducting events show the lowest refractivity gradients. Higher up in the atmosphere the gradient increases, where tropical events are generally lower. The found gradient does not support ducting conditions above about 2.5 km. On the basis of our study, about 4% of all occultations can be affected by ducts in the altitude range of 0.2–2.5 km. The number of affected occultations depends on the latitude band; none are found at polar latitudes, 2% are at midlatitudes, and about 10% are at tropical locations.
Role of sonification in shell weight measurements
Authors: Broecker Wallace S. , Clark Elizabeth
Published: November 2003

While the sonification step in Lohmann's [1995] shell weight paleocarbonate proxy method is necessary for the removal of detritus contained in the chambers of foraminifera shells, it has a drawback in that it preferentially induces the breakup of thin‐walled shells and hence biases shell weight measurements toward the thick‐walled end of the spectrum. This bias is particularly large for samples which have been weakened by dissolution.
Effect of magnetostatic interactions on the hysteresis parameters of single‐domain and pseudo‐single‐domain grains
Authors: Muxworthy Adrian , Williams Wyn , Virdee Davinder
Published: November 2003

From experiments it is known that magnetostatic interactions between grains strongly affect the magnetic behavior of samples. However, because of the difficulty in predicting the nonlinear behavior, the effect of interactions has been largely ignored from theoretical models. Instead models are often based on noninteracting assemblages. This approximation is valid for certain natural systems, but there are many cases where interactions are known to be important, for example, bacterial magnetosomes found in sedimentary rocks. Using a three‐dimensional micromagnetic model, we have conducted a detailed study of the role of magnetostatic interactions on the magnetic properties of assemblages of ideal single domain (SD) grains and cubic grains between 30–250 nm in size. We quantify the contribution of interactions to hysteresis parameters and the Day plot. We show that interactions can strongly affect the magnetic characteristics of a grain assemblage. For example, assemblages of interacting SD grains can plot in the traditional multidomain (MD) area of the Day plot. For grains >100 nm in size, interactions can have the opposite effect, and can cause the hysteresis parameters to shift toward the SD region of the Day plot. In addition to varying grain size, we have also considered various anisotropies, e.g., uniaxial and cubic, and the importance of the alignment configuration of the particle assemblages, i.e., randomly distributed or aligned. It is shown that for assemblages of aligned magnetite particles, that as the interaction spacing is decreased, the SD/MD transition size increases, which may explain why some magnetotatic bacteria possess aligned grains of magnetite above the traditional transition size value of 70 nm. By aligning the anisotropies, the grains become stable SD, and having larger crystals will increase the magnetic signal.
Perforated shell and stone objects from Sharm
Authors: Barker Diane
Published: November 2003

A group of six shell and four stone perforated objects is examined with a view to determining their function. Several possibilities are suggested as a result of a number of parallels in southeastern Arabia.
Thermal history analysis by integrated modelling of apatite fission track and vitrinite reflectance data: application to an inverted basin (Buller Coalfield, New Zealand)
Authors: Kamp Peter J. J. , Webster Kerry S. , Nathan Simon
Published: November 2003

Integrated analysis and modelling of apatite fission track with vitrinite reflectance (VR) data allows the timing, magnitude and pattern of Palaeogene subsidence and Neogene inversion to be established for an uplifted and largely denuded basin: the Buller Coalfield, New Zealand. At the time of maximum subsidence in the late Oligocene, the basin consisted of an extensional half graben, bounded to the west by the Kongahu Fault Zone (KFZ), with up to 6 km of upper Eocene to Oligocene section adjacent to it; currently, only a few tens of metres of basal coal measures on basement are preserved on top of a range 800–1000 m above sea level. Integrated modelling of the VR and fission track data show that the deepest parts of the basin were inverted during two Miocene compressional phases (24–19 Ma and 13–8 Ma), and are consistent with a further phase of inversion during the Quaternary that formed the present topography. Palinspastic restoration of the three phases of inversion shows that the basin was not inverted in a simple way: most of the rock uplift/denudation adjacent to the KFZ occurred during the early Miocene phase, and at the same time burial occurred in the south‐eastern part of the basin (maximum temperatures were experienced at different times at different places in the basin); during the middle to late Miocene there was broad uplift in the central and eastern parts of the coalfield. Because the timing and magnitude of uplift have been derived from the zone of inversion, they can be compared independently with the timing of unconformity development and rapid subsidence in the adjacent foredeeps, particularly the Westport Trough. For the middle to late Miocene phase of inversion, we show that during the first 1–2 million years of compression, the uplift within the coalfield also involved the margins of the Westport Trough, contributing to unconformity development; subsequently, uplift continued on the inversion structure but the margins of the Westport Trough subsided rapidly. This is explained by a model of stick slip behaviour on the boundary faults, especially for the KFZ. When compression started the fault zone has locked and uplift extends into the basin, whereas subsequently the fault zone unlocks, and the inversion structure overrides the basin margin, thereby loading it and causing subsidence.
Evolution of a Neoproterozoic to Palaeozoic intracratonic setting, Officer Basin, South Australia
Authors: Lindsay John F. , Leven James H.
Published: November 2003

The Neoproterozoic basins of central Australia share many features of architecture and sedimentary fill, suggesting common large‐scale extrinsic causal mechanisms. In an attempt to improve understanding of these mechanisms we have gathered and analysed new deep seismic reflection data and re‐evaluated existing seismic and well‐log data from the eastern Officer Basin, the largest and most poorly known of Australia's intracratonic basins.

The Officer Basin is asymmetric and has a steep thrust‐controlled northern margin paralleled by sub‐basins as much as 10 km in depth. Further south the basin shallows gradually onto a broad platform. The basin rests on a thick crust (≈42 km) that is pervaded by a complex of northward‐dipping surfaces most of which terminate erosionally against the sediments of the Officer Basin and are interpreted as prebasinal features, possibly faults. Some appear to have been zones of crustal weakness which were reactivated as thrust complexes and played a major role in basin evolution.

The sedimentary succession can be subdivided into six megasequences separated by major tectonically and erosionally enhanced sequence boundaries. The megasequences have distinctive sequence stacking patterns suggesting that they were deposited in response to episodic subsidence induced by a major extrinsic tectonic event. The basin initially formed as part of a giant sag basin which incorporated all the present‐day intracratonic basins (Amadeus, Georgina, Ngalia, Officer and Savory Basins) in a single large ‘superbasin’ perhaps as a response to mantle processes. Subsidence then ceased for ≈100 Myr producing a regional erosion surface. Beginning in the Torrensian or Sturtian five more major events of varying regional significance influenced the basin's evolution. Four were compressional events, the first of which activated major thrust complexes along the present basin margins, forming deep foreland sub‐basins with elevated intervening basement blocks. Once activated, the thrust complexes and sub‐basins persisted throughout the life of the intracratonic basins. From this epoch the intracratonic basins of central Australia were decoupled from the giant sag basin and became interrelated but independent features.

Available information suggests that the Officer, Amadeus, Georgina, Ngalia and Savory Basins are related and are perhaps products of major tectonic events associated with the assembly and ultimate dispersal of the Proterozoic supercontinent. The closing phases of these basins were strongly influenced by events occurring along the newly created active eastern margin of the Australian continent in the Palaeozoic.
Predicting sediment flux from fold and thrust belts
Authors: Tucker Gregory E. , Slingerland Rudy
Published: November 2003

The rate of sediment influx to a basin exerts a first‐order control on stratal architecture. Despite its importance, however, little is known about how sediment flux varies as a function of morphotectonic processes in the source terrain, such as fold and thrust growth, variations in bedrock lithology, drainage pattern changes and temporary sediment storage in intermontane basins. In this study, these factors are explored with a mathematical model of topographic evolution which couples fluvial erosion with fold and thrust kinematics. The model is calibrated by comparing predicted topographic relief with relief measured from a DEM of the Central Zagros Mountains fold belt. The sediment‐flux curve produced by the Zagros fold belt simulation shows a delay between the onset of uplift and the ensuing sediment flux response. This delay is a combination of the natural response time of the geomorphic system and a time lag associated with filling, and then subsequently uplifting and re‐eroding, the proximal part of the basin. Because deformation typically propagates toward the foreland, the latter time lag may be common to many ancient foreland basins. Model results further suggest that the response time of the bedrock fluvial system is a function of rock resistance, of the width of the region subject to uplift and erosion, and, assuming a nonlinear dependence of fluvial erosion upon channel gradient, of uplift rate. The geomorphic response time for the calibrated Zagros model is on the order of a few million years, which is commensurate with, or somewhat larger than, typical recurrence intervals for episodes of thrusting. However, model experiments also highlight the potential for significant variations in both geomorphic response time and in sediment flux as a function of varying rock resistance. Given a reasonable erodibility contrast between resistant and erodible lithologies, model sediment flux curves show significant sediment flux variations that are related solely to changes in rock resistance as the outcrop pattern changes. An additional control on sediment flux to a basin is drainage diversion in response to folding or thrusting, which can produce major shifts in the location and magnitude of sediment source points. Finally, these models illustrate the potential for a significant mismatch between tectonic events and sediment influx to a basin in cases where sediment is temporarily ponded in an intermontane basin and later remobilized.
Flexural uplift of the Stara Planina range, central Bulgaria
Authors: Roy M. , Royden L. H. , Burchfiel B. C. , Tzankov Tz. , Nakov R.
Published: November 2003

The Stara Planina is an E–W‐trending range within the Balkan belt in central Bulgaria. This topographically high mountain range was the site of Mesozoic through early Cenozoic thrusting and convergence, and its high topography is generally thought to have resulted from crustal shortening associated with those events. However, uplift of this belt appears to be much younger than the age of thrusting and correlates instead with the age of Pliocene–Quaternary normal faulting along the southern side of the range. Flexural modelling indicates the morphology of the range is consistent with flexural uplift of footwall rocks during Pliocene–Quaternary displacement on S‐dipping normal faults bounding the south side of the mountains, provided that the effective elastic plate thickness of 12 km under the Moesian platform is reduced to about 3 km under the Stara Planina. This small value of elastic plate thickness under the Stara Planina is similar to values observed in the Basin and Range Province of the western United States, and suggests that weakening of the lithosphere is due to heating of the lithosphere during extension, perhaps to the point that large‐scale flow of material is possible within the lower crust. Because weakening is observed to affect the Moesian lithosphere for ≈10 km beyond (north of) the surface expression of extension, this study suggests that processes within the uppermost mantle, such as convection, play an active role in the extension process. The results of this study also suggest that much of the topographic relief in thrust belts where convergence is accompanied by coeval extension in the upper plate (or ‘back arc’), such as in the Apennines, may be a flexural response to unloading during normal faulting, rather than a direct response to crustal shortening in the thrust belt.