bluuebunny/crossref_metadata_2025 huggingface dataset:
Chemoprotective effect of plant phenolics against anthracycline‐induced toxicity on rat cardiomyocytes Part II. caffeic, chlorogenic and rosmarinic acids
Authors: Chlopčíková Šárka , Psotová Jitka , Miketová Petra , Soušek Jaromír , Lichnovský Václav , Šimánek Vilím
Published: May 2004

The chemoprotective effects of caffeic (CA), chlorogenic (CHA) and rosmarinic (RA) acids were tested against the toxicity of doxorubicin (DOX) in neonatal rat cardiomyocytes and the iron‐dependent DOX induced lipid peroxidation of heart membranes, mitochondria and microsomes. The protectivity of these acids was compared with dexrazoxan, used as an adjuvant during DOX chemotherapy. The cytoprotective effects were assessed by enzyme (LDH and ASAT) and troponin I leakage, secondly by intracellular ATP content. All hydroxycinnamic acids proved non‐cytotoxic, and they stabilized both membranes and the energetic status of cardiomyocytes. After preincubation of cardiomyocytes with the test compounds (100, 200 µm; 1 h) the cardiomyocytes were treated with the toxic agent, DOX (100 µm; 8 h). The test compounds protected cardiomyocytes against DOX induced oxidative stress (RA > CHA ≥ CA) on all monitored parameters. Substantial preservation of monolayer integrity of the cardiomyocytes by test compounds was also found microscopically. All the acids were more effective in the assays used than dexrazoxan. RA showed the most effective cytoprotectivity. All the acids signiﬁcantly reduced the iron‐dependent DOX induced lipid peroxidation of heart membranes, although of the test compounds, CHA was found to be the most effective (IC50 = 8.04 ± 0.74/6.87 ± 0.52 µm for microsomes/mitochondria). Copyright © 2004 John Wiley & Sons, Ltd.
Pentazol‐Derivate und daraus entstehende Azide: [O3S—p‐C6H4—N5]— und [O3S—p‐C6H4—N3]— als Kalium‐Kronenether‐Salze
Authors: Biesemeier Frank , Harms Klaus , Müller Ulrich
Published: May 2004

—O3S—p‐C6H4—N2+ wurde bei —50 °C mit Natriumazid in Methanol umgesetzt. Dabei entstand das 4‐Pentazolylbenzolsulfonat [O3S—C6H4—N5]— neben 4‐Azidobenzolsulfonat (Stoffmengenverhältnis in der Lösung 27:73 nach NMR). Nach Zusatz von KOH in Methanol fiel bei —50 °C das Gemisch der Kaliumsalze K[O3S—p‐C6H4—N5] + K[O3S—p‐C6H4—N3] im Verhältnis 60:40 aus. Aus einer Lösung dieses Gemisches und 18‐Krone‐6 in Tetrahydrofuran wurde nach Zusatz von Petrolether bei —70 °C das kristalline Pentazol‐Derivat [THF‐K‐18‐Krone‐6] [O3S—p‐C6H4—N5]·THF erhalten. Aus derselben Lösung wurde nach Eindampfen und Wiederauflösen in THF/Petrolether bei —30 °C das kristalline Azid [THF‐K‐18‐Krone‐6][O3S—p‐C6H4—N3]·THF erhalten. Aus einer Lösung von letzterem in Chloroform/Toluol entstand an Luft [K‐18‐Krone‐6][O3S—p‐C6H4—N3]·1/3H2O. Nach den Röntgenstrukturanalysen haben [THF‐K‐18‐Krone‐6][O3S—p‐C6H4—N5]·THF und [THF‐K‐18‐Krone‐6][O3S—p‐C6H4—N3]·THF die gleiche Kristallpackung. Nennenswerte Unterschiede gibt es nur bei den Atomlagen des Pentazolrings im Vergleich zur Azidogruppe und bei einem THF‐Molekül, das an das Kaliumion koordiniert ist; mit den verschiedenen Orientierungen des THF‐Moleküls wird der verschiedene Platzbedarf von N5 bzw. N3 ausgeglichen. In [K‐18‐Krone‐6][O3S—p‐C6H4—N3]·1/3H2O ist neben einer Baugruppe aus einem [K‐18‐Krone‐6]+‐Ion mit einem [O3S‐C6H4—N3]—‐Ion eine Baugruppe vorhanden, in der zwei [O3S‐C6H4—N3]—‐Ionen über zwei [K‐18‐Krone‐6]+‐Ionen und ein Wassermolekül zusammengehalten werden. Die Geschwindigkeitskonstanten für den Zerfall [O3S‐C6H4—N5]— → [O3S‐C6H4—N3]— + N2 in Methanol wurden bei 0 °C und —20 °C bestimmt.
Crystal Structure of a Cadmium Iodate Monohydrate: Cd(IO3)2·H2O
Authors: Bentria Bachir , Benbertal Djamal , Bagieu‐Beucher Muriel , Mosset Alain
Published: May 2004

Single crystals of Cd(IO3)2·H2O are obtained by slow evaporation of aqueous solutions of CdCl2 and KIO3. This compound crystallizes in the triclinic space group P1¯ [a = 7.119(2), b = 7.952(2), c = 6.646(2)Å, α = 102.17(2)°, β = 114.13(2)°, γ = 66.78(4)°]. The structure consists in Cd — (μ2‐O)2 — Cd dimers with a metal — metal distance of 3.74Å. These dimers are connected through two iodate bridges resulting in layers parallel to the (010) plane. The 3D linkage is ensured by I1 — O1 long bonds (2.775Å).
Crystal Structures and Raman Spectra of cis‐[SnCl4(H2O)2]·2H2O, cis‐[SnCl4(H2O)2]·3H2O, [Sn2Cl6(OH)2(H2O)2]·4H2O, and [HL][SnCl5(H2O)]·2.5H2O (L=3‐acetyl‐5‐benzyl‐1‐phenyl‐4, 5‐dihydro‐1, 2, 4‐triazine‐6‐one oxime, C18H18N4O2)
Authors: Shihada Abdel‐Fattah , Abushamleh Ahmad S. , Weller Frank
Published: May 2004

The complexes cis‐[SnCl4(H2O)2]·2H2O (1), [Sn2Cl6(OH)2(H2O)2]·4H2O (3), and [HL][SnCl5(H2O)]·2.5H2O (4) were isolated from a CH2Cl2 solution of equimolar amounts of SnCl4 and the ligand L (L=3‐acetyl‐5‐benzyl‐1‐phenyl‐4, 5‐dihydro‐1, 2, 4‐triazine‐6‐one oxime, C18H18N4O2) in the presence of moisture. 1 crystallizes in the monoclinic space group Cc with a = 2402.5(1) pm, b = 672.80(4) pm, c = 1162.93(6) pm, β = 93.787(6)° and Z = 8. 4 was found to crystallize monoclinic in the space group P21, with lattice parameters a = 967.38(5) pm, b = 1101.03(6) pm, c = 1258.11(6) pm, β = 98.826(6)° and Z = 2. The cell data for the reinvestigated structures are: [SnCl4(H2O)2]·3H2O (2): a = 1227.0(2) pm, b = 994.8(1) pm, c = 864.0(1) pm, β = 103.86(1)°, with space group C2/c and Z = 4; 3: a = 961.54(16) pm, b = 646.29(7) pm, c = 1248.25(20) pm, β = 92.75(1)°, space group P21/c and Z = 4.
Ga2Br2R2 und Ga3I2R3 [R = C(SiMe3)3] — zwei neue elementorganische Galliumsubhalogenide mit einer bzw. zwei Ga‐Ga‐Bindungen
Authors: Uhl Werner , El‐Hamdan Abdelhakim , Geiseler Gertraud , Harms Klaus
Published: May 2004

Die vorsichtige Oxidation des tetraedrischen Tetragalliumclusters Ga4[C(SiMe3)3]4 (1) mit elementarem Brom in Gegenwart von AlBr3 führt zur Bildung des entsprechenden Subhalogenids Ga2Br2R2 [4, R = C(SiMe3)3], das überraschenderweise selbst im Festkörper monomer vorliegt und in dem die zweiwertigen Galliumatome über eine kurze Ga‐Ga‐Einfachbindung [243, 2(2) pm] miteinander verbunden sind. Die analoge Digalliumdiiod‐Verbindung Ga2I2R2 (3), die bereits früher in unserer Arbeitsgruppe auf ähnlichem Weg erhalten wurde, reagiert mit Lithium‐tert‐butanolat nicht unter Substitution, sondern unter teilweiser Disproportionierung zu dem Trigalliumdiiodid Ga3I2R3 (6), in dem drei Galliumatomen über zwei Ga‐Ga‐Einfachbindungen (255, 1 pm im Mittel) miteinander verbunden sind. Die beiden terminalen Galliumatome erreichen durch die Ausbildung zweier Iodobrücken die Koordinationszahl vier, während das innere, einwertige Galliumatom koordinativ ungesättigt bleibt. Die mittlere Oxidationsstufe der Zentralatome in der Kette beträgt +1, 66. Als zweites Produkt der Disproportionierung wurde die Gallium(III)‐Verbindung {[GaI(R)(OCMe3)(OH)]Li}2 (7) isoliert, die über Li‐O‐Brücken dimer vorliegt und eine gehinderte Rotation der tert‐Butylgruppe aufweist.
Metalated Container Molecules
Authors: Kersting Berthold
Published: May 2004

The coordination chemistry of metalated container molecules is currently attracting much interest, because the properties of such compounds are often different from those of their constituent components. By adjusting the size and form of the binding cavity it is often possible to coordinate coligands in unusual coordination modes, to activate and transform small molecules, or to stabilize reactive intermediates. Such compounds also allow for an interplay of molecular recognition and transition‐metal catalysis, and for the construction of more effective enzyme mimics. Consequently, a number of research groups are involved in the development of new supporting ligands that create confined environments about active metal coordination sites. This research report briefly reviews recent progress in this field including the results of my own group. It is shown that N‐functionalized derivatives of Robson‐type macrocyclic hexaaza‐dithiophenolate ligands form bioctahedral transition metal complexes of the type [(LR)M2(μ‐L′)]+ (M = Mn, Fe, Co, Ni, Zn) with an overall calixarene‐like structure. These complexes are amongst the first prototypes for polynuclear complexes with well defined binding cavities. Since the active coordination site L′ is accessible for a wide range of exogenous coligands, the [(LR)M2(μ‐L′)] complexes exhibit a rich coordination chemistry. It is demonstrated that the presence of the binding cavity influences many properties of the binuclear [(LR)MII2]2+ complex fragments, including color, molecular and electronic structure, hydrogen bonding interactions, redox potential, complex stability, and reactivity. The unusual properties of the complexes can be traced back to complementary host‐guest interactions and the distinct size and form of the binding pocket of the [(LMe)M2]2+ fragments.
Synthesis and Spectroscopic Characterization of Dinuclear Calcium Complexes with Oxa‐Aza Macrocyclic Ligands
Authors: Lodeiro Carlos , Bértolo Emilia , Capelo José Luis , Bastida Rufina
Published: May 2004

The syntheses of dinuclear calcium perchlorate and/or nitrate complexes by template and direct methods, employing macrocyclic ligands with 18, 20, 22, and 26 membered rings are reported. The presence of pendant arms provide with coordinative NxOy donor atoms in the smaller macrocycles, the high number of donor atoms between 7 and 10, and the dinuclear composition obtained in all the systems examined, point out that in the formed solid complexes both Ca2+ ions could be located inside of the macrocycle cavities. Transmetallation reaction of a lanthanide(III) complex, [L5Sm](ClO4)3·9H2O, with Ca(ClO4)2·xH2O leads the formation of the new dinuclear orange [L5Ca2](ClO4)4·3H2O complex, manifesting the versatility of this macrocyclic cavity.

All complexes have been characterized by microanalysis, IR, UV‐vis, 1H NMR spectroscopy, FAB mass spectrometry, FAAS spectroscopy, and conductivity measurements.
Liberty, utility, and justice: an ethical approach to unwanted pregnancy
Authors: Macklin Ruth
Published: May 2004

Three moral principles provide an ethical basis for the management of unwanted pregnancy. The principle of liberty guarantees a right to freedom of action; the utilitarian principle defines moral rightness by the greatest good for the greatest number; and justice requires that everyone have equitable access to necessary goods and services. Applied to unwanted pregnancy, these principles yield the conclusion that women have a natural right to reproductive freedom, and a social right to family planning and abortion services.
The need for a reproductive health approach
Authors: Sai Fred T. , Nassim Janet
Published: May 2004

A reproductive health approach recognizes that the foundations of women's health are laid in childhood and adolescence, and are influenced by factors such as nutrition, education, sexual roles and social status, cultural practices, and the socioeconomic environment. Reproductive health care strategies to meet women's multiple needs include education for responsible and healthy sexuality, safe and appropriate contraception, and services for sexually transmitted diseases, pregnancy, delivery, and abortion.
Abortion counseling: attention to the whole woman
Authors: Londoño E María Ladi
Published: May 2004

Women's experience of pregnancy and abortion are examined and redefined. Abortion may be undertaken for a variety of reasons, and involves not only physical and emotional health, but also a woman's basic identity. Under restrictive norm; and laws set by men, women's decision to abort is a subversive act. Recommendations are made for comprehensive services, including psychosocial counseling to help women cope with social pressures and experience ebortion as an act of self‐affirmation.
Protecting mammal diversity: opportunities and constraints for pragmatic conservation management in Cat Tien National Park, Vietnam
Authors: Polet Gert , Ling Stephen
Published: May 2004

A case study is given of a conservation management planning exercise underway in Cat Tien National Park and its surrounding areas in southern Vietnam. The importance of reliable information in this process is demonstrated using the Park's mammalian diversity. Opportunities and constraints to engage the local communities in conservation management planning and implementation are reviewed. The spatial element in protected area management planning is stressed; in some areas strict preservation management regimes are needed to conserve critical biodiversity values while in other areas conservation benefits could be gained from engaging local communities in resource management. Pragmatic conservation management planning decisions address identified threats, to be resolved by re-demarcation of boundaries, resettlement of people, and community-based conservation initiatives. These should result in a more viable Park as well as provide more secure livelihood conditions for the people elsewhere. This case study is put in the context of the wider conservation management debate.
High chimpanzee and gorilla densities in a non-protected area on the northern periphery of the Dja Faunal Reserve, Cameroon
Authors: Dupain J. , Guislain P. , Nguenang G. M. , De Vleeschouwer K. , Van Elsacker L.
Published: May 2004

Information on the densities of threatened species in non-protected areas is crucial for assessing the degree of isolation of adjacent protected areas and consequently their potential for preserving species from extinction. Relatively few studies, however, provide such information. We present the results of a survey of the densities of two great ape species, the gorilla Gorilla gorilla gorilla and chimpanzee Pan troglodytes troglodytes, in a non-protected area on the northern periphery of Dja Faunal Reserve, Cameroon. Densities of chimpanzees and gorillas were estimated to be 1.1 and 3.8 weaned individuals per km2, respectively. The results confirm that gorillas prefer building nests in vegetation types with limited visibility, and that within preferred vegetation types for nesting, gorillas select patches that are the most difficult to penetrate, resulting in less conspicuous nests. Although the opposite tendencies were exhibited by chimpanzees, no firm conclusions could be drawn from our data. Despite its non-protected status and past and ongoing logging activities in the area, the densities of gorillas and chimpanzees on the northern periphery of Dja Faunal Reserve are comparable to those found within the reserve itself, indicating the need for developing alternative conservation action to protect these important populations. The creation of a Communal Wildlife Zone in this area is legislatively possible, and could be an effective conservation tool because it has to originate from the local people.
Conservation status of the endemic fern Mankyua chejuense (Ophioglossaceae) on Cheju Island, Republic of Korea
Authors: Kim Chul Hwan
Published: May 2004

Mankyua chejuense, a fern endemic to Cheju Island, Republic of Korea, which lies 120 km south of the Korean Peninsula, appears to be restricted to five extant subpopulations in the north-east of the Island, with a total population of c. 1,300 individuals. Major threats to the existence of the species include shifting cultivation, plantation, overuse of basaltic rocks that are part of the species' microhabitat, farming and pasturage, and the construction of roads and golf courses in lowland areas. The information currently available for the species indicates that it should be categorized as Critically Endangered on the IUCN Red List. For conservation of the species it needs to be included on the national threatened species list, and its habitat designated as an ecological reserve. Intensive surveys are required in order to establish whether there are any other extant subpopulations of the species, and the presently known subpopulations require long-term monitoring and continuous protection.
What type of amphibian tunnel could reduce road kills?
Authors: Lesbarrères David , Lodé Thierry , Merilä Juha
Published: May 2004

Increased traffic volumes worldwide are contributing to amphibian declines, and measures to reduce the occurrence of road kills are needed. One possible measure is the construction of underpasses through which animals can pass under roads, but little is known about whether amphibians will choose tunnels if given a choice or about their preferences for different tunnel types. We tested the preferences of three anuran species for two kinds of concrete amphibian tunnels currently used in France. One was a tunnel lined with soil, the other a bare concrete pipe. The animals could use the tunnels or bypass them over a grassy area. Water frogs Rana esculenta and common toads Bufo bufo showed a preference for the tunnels, whereas agile frogs Rana dalmatina avoided them. Among the individuals that chose either of the tunnels, all species showed a significant preference for the tunnel lined with soil. These results indicate that species differ in their preferences and in their likelihood of using underpasses when given a choice. This highlights the fact that there is no unique solution to the problem, and underpasses are only one of the possible mitigation measures that need to be assessed.
High contribution of biogenic hydroperoxides to secondary organic aerosol formation
Authors: Bonn Boris , von Kuhlmann Rolf , Lawrence Mark G.
Published: May 2004

Secondary organic aerosols are believed to make an important contribution to the atmospheric radiation budget, though the exact mechanisms responsible for their formation are still uncertain. We compute a remarkably large contribution of hydroperoxides from the oxidation of biogenic monoterpenes. Although currently neglected in aerosol models, the hydroperoxides lead to 63% of our calculated global secondary organic aerosol formation, whereas carboxylic acids, usually considered as the dominant secondary organic aerosol precursors, were responsible for only 26%. Detailed studies are needed to determine the implications of this aerosol formation pathway for the total atmospheric aerosol burden and its impacts on climate.
Multisatellite measurements of electron phase space density gradients in the Earth's inner and outer magnetosphere
Authors: Taylor M. G. G. T. , Friedel R. H. W. , Reeves G. D. , Dunlop M. W. , Fritz T. A. , Daly P. W. , Balogh A.
Published: May 2004

The variability of the intensity of energetic (MeV) electrons in the Earth's radiation belts has been a renewed area of interest in recent years, yet a major outstanding question is the origin of these particles. In the current study we attempt to differentiate between local stochastic heating and radial diffusion or transport by investigating whether the plasma sheet contains a sufficient population of energetic electrons to supply relativistic electron enhancements in the Earth's radiation belts by radial transport alone or whether one needs to invoke other more localized acceleration processes. We have ordered the equatorial/central plasma sheet electron data from several satellites (GPS (∼4 RE), LANL geosynchronous (GEO) (∼6.6 RE), POLAR (∼8 RE), and CLUSTER (∼18 RE)) in phase space density (PSD). By combining these measurements at a particular value of the first adiabatic invariant, we are able to examine the radial profile of PSD. We present a case study of data from three successive CLUSTER orbits centered on a small to moderate (DST = −40 nT) geomagnetic storm to investigate the storm dynamics of the electron radial phase space gradient in the magnetotail. Our results indicate a steep outward PSD gradient to near geosynchronous orbit (∼trapping boundary) followed by a fairly flat to moderately rising outward PSD gradient into the plasmasheet near 18 RE, with CLUSTER PSDs highly dependent on the vicinity of the current sheet. We conclude that for this case, there appears to be a sufficient source of electrons to account for the populations of electrons in the inner magnetosphere (i.e., a positive radial gradient). However, evidence of a local PSD peak located between our GPS and POLAR radial positions suggests we cannot rule out local acceleration mechanisms.
Simultaneous observations of field‐aligned beams and gyrating ions in the terrestrial foreshock
Authors: Meziane K. , Wilber M. , Mazelle C. , LeQuéau D. , Kucharek H. , Lucek E. A. , Rème H. , Hamza A. M. , Sauvaud J. A. , Bosqued J. M. , Dandouras I. , Parks G. K. , McCarthy M. , Klecker B. , Korth A. , Bavassano‐Cattaneo M. B. , Lundin R. N.
Published: May 2004

We examine an energetic (2–30 keV) upstream ion event presenting a clear double‐peak spectrum observed ∼1 RE upstream from the bow shock. The lower‐energy (E ∼ 3.5 keV) peak is associated with an ion beam propagating along the magnetic field direction, while the higher‐energy (E ∼ 13 keV) peak is associated with gyrating ions having pitch angles ∼30°. The latter population progressively extends to lower energies over the span of the event. During times when the field‐aligned beams were observed, the interplanetary magnetic field was remarkably steady, while the appearance of the 30° pitch angle gyrating ions was accompanied by the onset of large‐amplitude ultralow frequency fluctuations of the magnetic field. Our analysis indicates that the gyrating ions had guiding centers on field lines downstream of the field‐aligned component but that both populations could be sampled simultaneously because of the orbits of the former. We find that the downstream limit of the field‐aligned beams is populated with protons having a speed 1.68 times the solar wind velocity, which is inconsistent with any known shock‐related emission mechanisms. This boundary makes an angle of 77° with respect to the Sun‐Earth line in agreement with theoretical predictions. Just downstream of this rapid transition, gyrating ions having a flow speed of 1.52 times the solar wind speed are observed in association with ULF waves. Like the field‐aligned beams, the gyrating ions reported here have streaming speeds inconsistent with any known shock emission mechanisms. While the simultaneous observation of field‐aligned and gyrating components is possible because of the large gyration orbits of the latter, the observational sequence is consistent with a very sharp (≲1 gyroradius) boundary separating the guiding centers of each. Explicit observations of such a sharp demarcation between these populations have not been reported before, and they place a significant constraint on the production mechanisms of the two populations. Our interpretation of these observations provides a refinement of the usual framework for foreshock morphology.
Physical balances in subseafloor hydrothermal convection cells
Authors: Jupp Tim E. , Schultz Adam
Published: May 2004

We use a simplified model of convection in a porous medium to investigate the balances of mass and energy within a subseafloor hydrothermal convection cell. These balances control the steady state structure of the system and allow scalings for the height, permeability, and residence time of the “reaction zone” at the base of the cell to be calculated. The scalings are presented as functions of (1) the temperature TD of the heat source driving the convection and (2) the total power output ΦU. The model is then used to illustrate how the nonlinear thermodynamic properties of water may impose the observed upper limit of ∼400°C on vent temperatures. The properties of water at hydrothermal conditions are contrasted with those of a hypothetical “Boussinesq fluid” for which temperature variations in fluid properties are either linearized or ignored. At hydrothermal pressures, water transports a maximum amount of energy by buoyancy‐driven advection at ∼400°C. This maximum is a consequence of the nonlinear thermodynamic properties of water and does not arise for a simple Boussinesq fluid. Inspired by the “Malkus hypothesis” and by recent work on dissipative systems, we speculate that convection cells in porous media attain a steady state in which the upwelling temperature TU maximizes the total power output of the cell. If true, this principle would explain our observation (in previous numerical simulations) that water in hydrothermal convection cells upwells at TU ∼ 400°C when driven by a heat source above ∼500°C.
Relating magnetic susceptibility (MS) to the simulated thematic mapper (TM) bands of the Chinese loess: Application of TM image for soil MS mapping on Loess Plateau
Authors: Ji Junfeng , Chen Jun , Jin Li , Zhang Wanchang , Balsam William , Lu Huayu
Published: May 2004

Magnetic susceptibility (MS) is a very important physical attribute of the Earth's soils and surficial sediments. Soil‐containing deposits in the Loess Plateau of central China offer a unique opportunity to study the relationship between soil reflectance and MS. In this paper, data on MS and diffuse reflectance spectra obtained from seven Loess Plateau sections were used to establish quantitative relationships between MS and spectral parameters related to remote sensing. By integrating the diffuse reflectance values corresponding to thematic mapper (TM) channels, five TM bands were simulated and served as independent variables for a multiple linear regression relating the bands to MS. The resulting calibration equation provides good estimates of MS values and has excellent correlation coefficients, >0.90, for all the test samples. The application of the regression equation for mapping soil MS was performed using the enhanced TM image from northwest part of Loess Plateau. The MS values obtained from TM data are convincing and compare well with the limited field test data. The spatial MS variations on the TM image clearly show a decrease toward the northwest and are in a good agreement with the monsoon directions. Results of this study demonstrate that the surface MS signal in soil can be mapped with data from satellite‐based remote sensors operating in the visible and near‐infrared bands. The future possibilities of this method in other soil types and climates need to be explored.
Asymptotic analysis of bound‐mode and free‐space residual‐wave currents excited by a delta‐gap source on a microstrip line
Authors: Baccarelli P. , Burghignoli P. , Frezza F. , Galli A. , Lovat G. , Paulotto S.
Published: May 2004

In this work, an asymptotic analysis is presented for bound‐mode and free‐space residual‐wave currents, with the aim of obtaining an analytical representation of the continuous‐spectrum current excited by a delta‐gap source on a microstrip line. The proposed approach is valid in a frequency region which extends through the entire spectral gap of the dominant leaky mode. The analysis proves in a rigorous way the different asymptotic behaviors of the TM0 bound‐mode and free‐space residual‐wave currents. The relevance of the nature of the involved branch points to these asymptotic behaviors is also discussed. An explicit expression for the numerical coefficient arising in the asymptotic expansion obtained through Watson's Lemma is provided in a simple closed form for both types of residual‐wave current. Analytical details are supplied, together with numerical results which confirm the predicted asymptotic behaviors and the accuracy of the closed‐form representation also in proximity of the source, if the presence of singularities of the relevant spectral integrands is properly taken into account.
Sound velocities and elasticity of aluminous MgSiO3 perovskite: Implications for aluminum heterogeneity in Earth's lower mantle
Authors: Jackson Jennifer M. , Zhang Jianzhong , Bass Jay D.
Published: May 2004

Aluminum has been reported to have a remarkably strong effect on the thermoelastic properties of MgSiO3 perovskite. However, the sound velocities of aluminous MgSiO3 perovskite have not been previously measured, even though this phase likely dominates most of the chemistry in Earth's lower mantle. Here we report the first sound velocity measurements on aluminous MgSiO3 perovskite using Brillouin spectroscopy and obtain the following values for the room‐pressure room‐temperature adiabatic bulk and shear moduli: KS = 252 ± 5 GPa and μ = 165 ± 2 GPa, respectively. The presence of 5.1 ± 0.2 wt.% Al2O3 in MgSiO3 perovskite decreases the shear modulus by 5.6%. However, within experimental uncertainties, there is no discernable effect of aluminum on the bulk modulus. We find that variations in the aluminum content of MgSiO3 perovskite may provide an explanation for some observed lateral heterogeneity in Earth's lower mantle.
Estrogens and the hair follicle
Authors: Conrad Franziska , Paus Ralf
Published: May 2004

While it is undisputed that estrogens (17β‐estradiol, E2) are mainly involved in skin physiology and operate as potent hair growth modulators, our knowledge about the estrogen target cells in skin and exact signaling pathways is still very limited. The current review provides an overview of estrogen effects on hair follicle cycling, cutaneous expression of estrogen receptors, and potential functions of estrogens in hair biology. We discuss potential target genes of estrogen receptor‐mediated signaling in the skin, explore the interplay of estrogens with other hormones, growth factors and enzymes, and define major open questions in this intriguing and far too long neglected area of hair research.
Differential diagnosis of hair loss in children
Authors: Mandt Nathalie , Vogt Annika , Blume‐Peytavi Ulrike
Published: May 2004

Hair loss in childhood covers a broad differential diagnosis and often presents the involved dermatologist and pediatrician with a diagnostic and therapeutic challenge. Correct classification of the hair disease, especially in the case of underlying genetic syndromes, metabolic defects or endocrine disorders, is often an important prerequisite for continued normal physical and mental development of the young patients. Dealing with hair loss in childhood, one should differentiate between congenital and acquired diseases. The clinical manifestation profile, the age of the patient when the initial manifestation occurred, and the presence of associated symptoms are important for the classification of the hair disease. In the present paper, a classification of hair loss in childhood based on clinical appearance, age of onset and associated symptoms is proposed as a guide for the evaluation of hair loss and alopecia in childhood.
The impact of rabbit haemorrhagic disease on wild rabbit (Oryctolagus cuniculus) populations in Queensland
Authors: Story G. , Berman D. , Palmer R. , Scanlan J.
Published: May 2004

Rabbit haemorrhagic disease virus (RHDV) escaped from quarantine facilities on Wardang Island in September 1995 and spread through South Australia to Queensland by December 1995. To determine the impact of this biological control agent on wild rabbit populations in Queensland, shot sample and spotlight count data were collected at six sites. RHDV spread across Queensland from the south-west to the east at a rate of at least 91 km month–1 between October 1995 and October 1996. The initial impact on rabbit density appeared highly variable, with an increase of 81% (255 ± 79 (s.e.) to 385 ± 73 rabbits km–2) at one site and a decrease of 83% (129 ± 27 to 22 ± 18 rabbits km–2) at another during the first outbreak. However, after 30 months of RHDV activity, counts were at least 90% below counts conducted before RHDV arrived. Using a population model to account for environmental conditions, the mean suppression of rabbit density caused by rabbit haemorrhagic disease (RHD) was estimated to be 74% (ranging from 43% to 94% between sites). No outbreaks were observed when the density of susceptible rabbits was lower than 12 km–2. Where rabbit density remains low for long periods RHDV may not persist. This is perhaps most likely to occur in the isolated populations towards the northern edge of the range of rabbits in Australia. RHDV may have to be reintroduced into these populations. Further south in areas more suitable for rabbits, RHDV is more likely to persist, resulting in a high density of immune rabbits. In such areas conventional control techniques may be more important to enhance the influence of RHD.
Adaptation and assessment of M-44 ejectors in a fox-control program on Phillip Island, Victoria
Authors: Petel A. Marjolein van Polanen , Kirkwood Roger , Gigliotti Frank , Marks Clive
Published: May 2004

This study aimed to adapt M-44 ejectors for use in sandy soils and to assess the feasibility of incorporating the modified M-44s into a long-term fox-control program on Phillip Island, Victoria. M-44s were adapted by burying a plastic cylinder around them, which prevented sandy soil from collapsing and inhibiting the trigger mechanism, and at the same time orientated the fox's mouth vertically over the M-44 to maximise the dose of poison delivered. The fast-acting poison sodium cyanide was used to ensure the collection of fox bodies and any non-target animals. A fox was killed on 78.6% of occasions that an M-44 was triggered. No non-target species triggered M-44s, although rodents and birds occasionally ate the unpoisoned baits. The modified M-44 ejector technique accounted for 19% of foxes killed by all techniques during one year on Phillip Island. To assess whether M-44s were a worthwhile technique to include in the fox-control program on Phillip Island, we compared their catch per unit effort (number of foxes killed per 1000 person-hours) with other control techniques (spotlight shooting, treadle snaring and hunting with fox hounds). Deployment of M-44s with cyanide was labour intensive, due to safety considerations, and cyanide can be used only as a research tool. Future management use of the M-44s would be with sodium monofluoroacetate (1080), so an estimate was made of the catch per unit effort of M-44s with this poison. Results suggest that deployment of M-44s with 1080 is likely to be more time-effective than the other techniques.
Levels and probable origin of predatory scarring on humpback whales (Megaptera novaeangliae) in east Australian waters
Authors: Naessig Patricia J. , Lanyon Janet M.
Published: May 2004

To investigate the incidence of non-lethal predation in Southern Hemisphere whales, more than 3400 fluke-identification photographs from resight histories of 1436 east Australian humpback whales were examined for evidence of predatory markings. Photographs were obtained from 1984 to 1996 at various locations along the east coast of Australia, from northern Queensland to southern New South Wales. Photographs were classified in terms of the level and type of scarring. The possible predator and whether the markings appeared fresh were also noted. In all, 17% of identified east Australian humpbacks possessed some form of predatory scarring, 57% of which was minor and 43% major. Almost all predatory scarring was consistent with that inflicted by killer whales. Only three whales demonstrated an increase in the level of predatory scarring after their first sightings. Two incidents of fresh scarring were recorded, and one fatal killer whale attack on a humpback whale calf was directly observed. The overall level of predatory scarring found in this study is comparable to those found in studies for Northern Hemisphere humpback whales. The low incidence of adult whales showing their first sign of predatory scarring after their initial sighting, and the small number possessing recent scarring, support the idea that east Australian humpback whales experience most predatory attacks early in life.
Ancient polyploidization predating divergence of the cereals, and its consequences for comparative genomics
Authors: Paterson A. H. , Bowers J. E. , Chapman B. A.
Published: May 2004

Integration of structural genomic data from a largely assembled rice genome sequence, with phylogenetic analysis of sequence samples for many other taxa, suggests that a polyploidization event occurred ≈70 million years ago, before the divergence of the major cereals from one another but after the divergence of the Poales from the Liliales and Zingiberales. Ancient polyploidization and subsequent “diploidization” (loss) of many duplicated gene copies has thus shaped the genomes of all Poaceae cereal, forage, and biomass crops. The Poaceae appear to have evolved as separate lineages for ≈50 million years, or two-thirds of the time since the duplication event. Chromosomes that are predicted to be homoeologs resulting from this ancient duplication event account for a disproportionate share of incongruent loci found by comparison of the rice sequence to a detailed sorghum sequence-tagged site-based genetic map. Differential gene loss during diploidization may have contributed many of these incongruities. Such predicted homoeologs also account for a disproportionate share of duplicated sorghum loci, further supporting the hypothesis that the polyploidization event was common to sorghum and rice. Comparative gene orders along paleo-homoeologous chromosomal segments provide a means to make phylogenetic inferences about chromosome structural rearrangements that differentiate among the grasses. Superimposition of the timing of major duplication events on taxonomic relationships leads to improved understanding of comparative gene orders, enhancing the value of data from botanical models for crop improvement and for further exploration of genomic biodiversity. Additional ancient duplication events probably remain to be discovered in other angiosperm lineages.
Molecular imaging of gene expression in living subjects by spliceosome-mediated RNA trans-splicing
Authors: Bhaumik S. , Walls Z. , Puttaraju M. , Mitchell L. G. , Gambhir S. S.
Published: May 2004

Spliceosome-mediated RNA trans-splicing (SMaRT) provides an effective means to reprogram mRNAs and the proteins they encode. SMaRT technology has a broad range of applications, including RNA repair and molecular imaging, each governed by the nature of the sequences delivered by the pre-trans-splicing molecule. Here, we show the ability of SMaRT to optically image the expression of an exogenous gene at the level of pre-mRNA splicing in cells and living animals. Because of the modular design of pre-trans-splicing molecules, there is great potential to employ SMaRT to image the expression of any arbitrary gene of interest in living subjects. In this report, we describe a model system that demonstrates the feasibility of imaging gene expression by transsplicing in small animals. This represents a previously undescribed approach to molecular imaging of mRNA levels in living subjects.
The Origins of the Pioneer Cotton Mills in Minas Gerais, Brazil, 1868–1879: A Reassessment
Authors: Oliveira M. Teresa Ribeiro de
Published: May 2004

The Brazilian economy before the First World War has been generally characterized as an economy specializing in the production of primary goods for the international market—chiefly coffee for export. The emergence of the first industrial factories has been seen as closely connected to the performance of the export sector. The first cotton mills established in one province of Brazil, Minas Gerais, were not connected to the export sector, however. Minas Gerais was different in key respects from other regions. This article describes the peculiarities of the Mineiro economy during the 1870s and investigates the establishment of the first cotton mills there. It considers the location, size, and financing of the mills, as well as the structure of ownership and relations between partners. The results show that the emergence of the textile industry in Minas Gerais was independent from the performance of the foreign sector of the Brazilian economy.
Developing knowledge and skills in engineers: a learning laboratory
Authors: Platts K.W.
Published: May 2004

This paper discusses the knowledge and skill requirements for manufacturing system design and describes an innovative “learning laboratory” approach to educating graduate level manufacturing engineers. The laboratory provides a mechanism that gives engineers a wide range of knowledge and skills in design and implementation, much of which cannot be taught by traditional teaching methods.
Dynamic simulation of multiple deformable bodies using combined discrete and finite element methods
Authors: Komodromos Petros I. , Williams John R.
Published: May 2004

The discrete element methods (DEM) are numerical techniques that have been specifically developed to enable simulations of systems of multiple distinct, typically infinitely rigid, bodies that interact with each other through contact forces. However, there are multibody systems for which it is useful to consider the deformability of the simulated bodies and enable the evaluation of their stress and strain distributions. This paper focuses on the simulation of deformable multibody systems using a combination of DEM and finite element methods (FEM). In particular, an updated Lagrangian (UL) finite element (FE) formulation and an explicit time integration scheme are used together with some simplifying assumptions to linearize this highly nonlinear contact problem and obtain solutions with realistic computational cost and sufficiently good accuracy. In addition, this paper describes a software implementation of this formulation, which utilizes the Java programming language and the Java3D graphics application programming interface (API), as well as database technology.
A contact algorithm for partitioning N arbitrary sized objects
Authors: Williams John R. , Perkins Eric , Cook Ben
Published: May 2004

A new spatial reasoning algorithm that can be used in multi‐body contact detection is presented. The algorithm achieves the partitioning of N bodies of arbitrary shape and size into N lists in order O(N) operations, where each list consists of bodies spatially near to the target object. The algorithm has been tested for objects of arbitrary shape and size, in two and three dimensions. However, we believe that it can be extended to dimensions of four and higher. The algorithm (CGRID) is a binning algorithm that extends traditional binning algorithms so that the arbitrary sizes and shapes can be handled efficiently. The algorithm has applications in discrete element, finite element, molecular dynamics, meshless methods, and lattice‐Boltzmann codes and also in domains such as path planning, target acquisition and general clustering problems.
Comparison of experimental and FEM/DEM results for gravitational deposition of identical cubes
Authors: Munjiza A. , Latham J.P.
Published: May 2004

The combined finite‐discrete element method has been used to simulate the gravitational depositions of packs containing particles of cubical shape. This approach to the generation of particle packs is based on the simulation of the dynamics of pack formation including interaction among individual particles, inertia and gravitational forces. The results of such an approach are compared to the experimental results to evaluate both feasibility and accuracy of the combined finite‐discrete element simulation of packing problems.
Thin tunnel liners modelled with particle flow code
Authors: Tannant Dwayne D. , Wang Caigen
Published: May 2004

Simple discrete element models using PFC2D models with bonded assemblies of particles were used to numerically simulate direct tension and block punching tests on thin spray‐on tunnel liner materials to gain insight about the liner support mechanisms. PFC2D input parameters were calibrated such that the rupture load and elongation at rupture were similar to the laboratory test data. The calibrated model of the liner material was then used to simulate a liner around a highly stressed tunnel in rock where stresses caused extensive fracturing near the top of the tunnel. The effect of the liner was analysed by modelling the tunnel with and without the liner and showed that the liner had minimal impact on fracture propagation in the rock because of the liner's highly deformable nature. However, the liner was able to retain the fractured rock in place.
Simulations of underground structures subjected to dynamic loading using the distinct element method
Authors: Morris J.P. , Rubin M.B. , Blair S.C. , Glenn L.A. , Heuze F.E.
Published: May 2004

We present the preliminary results from a parameter study investigating the stability of underground structures in response to explosion‐induced strong ground motions. In practice, even the most sophisticated site characterization may lack key details regarding precise joint properties and orientations within the rock mass. Thus, in order to place bounds upon the predicted behavior of a given facility, an extensive series of simulations representing different realizations may be required. The influence of both construction parameters (reinforcement, rock bolts, liners) and geological parameters (joint stiffness, joint spacing and orientation, and tunnel diameter to block size ratio) must be considered. We discuss the distinct element method (DEM) with particular emphasis on techniques for achieving improved computational efficiency, including the handling of contact detection and approaches to parallelization. We introduce a new approach for simulating deformation of the discrete blocks using the theory of a Cosserat point, which does not require internal discretization of the blocks. We also outline the continuum techniques we employ to obtain boundary conditions for the distinct element simulations. We present results from simulations of dynamic loading of several generic subterranean facilities in hard rock, demonstrating the suitability of the DEM for this application. These results demonstrate the significant role that joint geometry plays in determining the response of a given facility.
Barriers to innovation within small firms in a peripheral location
Authors: McAdam Rodney , McConvery Thomas , Armstrong Gren
Published: May 2004

Designated peripheral regions within the European Union (EU) have economies and standards of living which are below average. One of the primary reasons recognised by local government for this poor economic standing has been low levels of innovation within indigenous small to medium‐sized enterprises (SMEs). These SMEs have difficulties in growing and exporting or being part of successful supply chains. The aim of this paper is to explore how innovation is successfully incorporated or hindered in SMEs within an EU peripheral region. An innovation model was applied in a multiple case study methodology involving 41 SMEs. Both quantitative and qualitative data were gathered and analysed. The paper concludes that SMEs must strategically plan for innovation and move beyond continuous improvement, or “kaizen”, and states that such plans must avoid quick fixes and address the underlying cultural barriers to innovation, such as organisational structure, owner‐manager leadership issues, a lack of empowerment and lack of use of employees' ideas and suggestions for innovation.
Researching work identities in a European context
Authors: Kirpal Simone
Published: May 2004

The contributions in this CDI special issue present research findings that have been generated in the course of the research project, Vocational Identity, Flexibility and Mobility in the European Labour Market, funded under the 5th EU Framework Programme. Investigating identity formation processes at work, the guiding research question focused on what individuals identify with in their work context when they are challenged to respond to increasing demands for flexibility, mobility, changing work settings and shifting skill requirements. Project partners from seven European countries (Czech Republic, Estonia, France, Germany, Greece, Spain and the UK) interviewed more than 500 employees at intermediate skills level and over 100 managers and representatives of human resources departments about how employees cope with changes at work and how this might affect their work identity, work attitude and career orientation. This paper gives an overview of the background, research questions, basic theoretical considerations, methodology and general findings of this project. It serves as a general introduction to the other five papers presented in this issue which are all based on a common approach and understanding of the research carried out.