bluuebunny/crossref_metadata_2025_split huggingface dataset:
Gedrite–garnet–sillimanite‐bearing granulites from Amessmessa area, south In Ouzzal, Hoggar, Algeria
Authors: OUZEGANE K. , DJEMAI S. , GUIRAUD M. 
Published: December 2004

ABSTRACTSome granulites from the Amessmessa area (south In Ouzzal unit, Hoggar) contain the peak assemblage gedrite+garnet+sillimanite+quartz that was used to estimate the P–T conditions of metamorphism. The rocks developed symplectites and corona textures by the breakdown of the primary paragenesis to orthopyroxene, cordierite and spinel. The successive parageneses formed in separate microdomains according to a clockwise P–T path. Geothermometry, geobarometry and phase diagram calculations indicate that the textures formed by decompression and cooling from 7–9 kbar and 850–900°C to 3.5–4.5 kbar and 700–800°C. This P–T evolution is consistent with low to medium aH2O, between 0.4 and 0.7, and is similar to the metamorphic conditions deduced in Al–Mg granulites from the north of In Ouzzal.
Major and trace element geochemistry and isotope (Sr, Nd, Pb, O) systematics of an Archaean basement involved in a 2.0 Ga very high‐temperature (1000°C) metamorphic event: In Ouzzal Massif, Hoggar, Algeria
Authors: PEUCAT J.‐J. , CAPDEVILA R. , DRARENI A. , CHOUKROUNE P. , FANNING C. M. , BERNARD‐GRIFFITHS J. , FOURCADE S. 
Published: December 2004

ABSTRACTThe In Ouzzal granulitic massif is composed mainly of various meta‐igneous rocks which, in spite of Rb, U, Th, Cs and some K and Sr mobility, can be dated and generally classified according to their chemical composition as follows.Basic and ultrabasic granulites interlayered with the metasediments correspond to (1) ultrabasic cumulates from dislocated tholeiitic bodies, (2) ancient komatiitic to high‐Mg tholeiitic basalts similar to the suites found in Archaean greenstone belts and (3) calcalkaline protoliths of high‐K andesitic composition. No geochronological constraints are available apart from the depositional age of some associated sediments which is younger than 2.70 Ga detrital zircons, and the Nd model age of the andesitic granulites of c. 3.4 Ga.In spite of the high‐grade metamorphism, the acidic magmatic precursors of the charnockites can be divided in three groups. (1) The most juvenile acid orthogneisses are trondhjemitic or tonalitic in composition, being similar to the TTG suites which are classically considered to be formed by partial melting of mantle‐derived protoliths. The 3.3–3.2 Ga TDM indicates a possible age of separation from the mantle reservoir while the plutons may have been emplaced between 3.3 and 2.7 Ga (U–Pb zircon & Nd ages). (2) A group of alkaline granitic gneisses, similar in composition to rift‐related‐granites, were emplaced at 2650±10 Ma (U–Pb & Rb–Sr ages) in a thick continental crust. (3) Calcalkaline granodioritic and monzogranitic suites derived from the partial melting of continental precursors (3.5–3.3 Ga), in lower to middle levels of the continental crust. They were emplaced close to 2.5 Ga during crustal thickening.The very high‐temperature metamorphism occurred at 2002±7 Ma from the age of synfoliation intrusions and was probably related to major overthrusting. Retrogressive metamorphism is dated at 1.95 Ga from garnet‐Nd ages. In spite of the very high‐temperature conditions, partial melting during granulite facies metamorphism may be restricted to scarce cordierite‐bearing monzogranitic gneisses. The 2.0 Ga VHT metamorphism could be related to overthrusting, extensional or underplating processes.
Probable anticlockwise P,–T evolution in extending crust: Hlinsko region, Bohemian Massif
Authors: PITRA P. , GUIRAUD M. 
Published: December 2004

ABSTRACT In the Hlinsko region (Variscan Bohemian Massif, Czech Republic) a major extensional shear zone separates low‐grade metasedimentary series (Hlinsko schists) and high‐grade rocks of the Moldanubian terrane (Svratka Crystalline Unit). During late‐Variscan extension, a tonalite intruded syntectonically into the normal ductile shear zone, and caused contact metamorphism of the overlying schists. Concurrent syntectonic sedimentation of a flysch series took place at the top of the hangingwall schists. In order to decipher the detailed petrological evolution of the Hlinsko unit situated in the hangingwall of this tectonic contact, a phase diagram approach and petrogenetic grids, calculated with the thermocalc computer program, were used.The crystallization/deformation relationships and the paragenetic analysis of the Hlinsko schists define a P–T path with an initial minor increase in pressure followed by cooling. Calculated pseudosections constrain this anticlockwise P‐T evolution to the upper part of the andalusite field between 0.36 and 0.40 GPa for temperatures ranging from 570 to 530°C. A low aH2O is required to explain the presence of andalusite‐biotite‐bearing assemblages, and could be related to the presence of abundant graphite.In contrast, the footwall rocks of the Svratka Crystalline Unit record decompression from around 0.8 GPa at a relatively constant temperature, followed by cooling. Thus, the footwall and the hangingwall units display opposite, but convergent P–T histories. Decompression in the footwall rocks is related to a rapid exhumation. We propose that the inverse, anticlockwise P–T path recorded in the hangingwall pelites is related to the rapid, extension‐controlled sedimentation of the overlying flysch series.
EVALUATION OF REGIONAL SUSTAINABLE DEVELOPMENT — TRANSITIONS AND PROSPECTS
Authors: RAVETZ JOE , COCCOSSIS HARRY , SCHLEICHER-TAPPESER RUGGERO , STEELE PATRICK 
Published: December 2004

Evaluation practice, "regional development" and "sustainability" are each complex and contentious. Each shows rapid trends and transitions, and opportunities to be gained for more integrated governance and regional development. This paper takes a case study approach, based on the "Evaluation Workshop" of the EU thematic network project REGIONET. The case studies each concerned the restructuring and modernization process: one in an industrial conurbation, another in an agricultural region and a third in a peripheral region. For each case study, the workshop sessions explored in depth the current evaluation practice, the technical tools, the social processes and the trends and prospects in sight. The results of this exploration highlight the rapid transitions emerging in several areas — in technical tools, in social participation and in multi-level governance. The implications are for a new kind of evaluation toolkit, a "meta-information system", which helps to link between existing methods and tools. They also point towards an evaluation approach that is based on a proactive "opportunity building", as much as a reactive "impact assessment".
Novel Slow- and Fast-Type Drug Release Round-Window Microimplants for Local Drug Application to the Cochlea: An Experimental Study in Guinea Pigs
Authors: Arnold Wolfgang , Senn Pascal , Hennig Michael , Michaelis Christiane , Deingruber Kerstin , Scheler Renate , Steinhoff Hans-Joachim , Riphagen Frits , Lamm Kerstin 
Published: December 2004

Novel drug release microimplants (0.8 × 1.14 mm; custom-made by Leiras, now Schering OY, Finland) of slow- and fast-release types containing either 0.9 mg beclomethasone or no drug at all were placed unilaterally onto the round-window membrane (RWM) of 45 guinea pigs for a maximum duration of 28 days. The following parameters were tested on days 1, 14 and 28 after implantation: threshold levels of beclomethasone in the perilymph of the scala tympani, auditory brain stem responses (ABR thresholds and ABR threshold shifts), RWM morphology and hair cell loss (cytocochleograms). None of the animals in the non-implanted control group (n = 5) or placebo implant group (n = 15), but all animals in the slow-release-type implant group (n = 15) and fast-release-type implant group (n = 15) revealed the presence of beclomethasone on day 1 (34.9 and 64.3 pg/µl, respectively), day 14 (43.8 and 46.9 pg/µl, respectively) and day 28 after implantation (4.7 and 60.5 pg/µl, respectively). Histology of the RWMs appeared normal, and cytocochleograms revealed no inner hair cell loss and outer hair cell loss within normal ranges (from 0.5 ± 0.4 to 0.8 ± 0.2% per cochlea) in both ears in all experimental groups at any time during examination (days 1, 14 and 28). Initial values of ABR thresholds at 3, 6, 9 and 12 kHz did not differ significantly in any of the experimental groups. In non-implanted controls, no significant differences of ABR thresholds were observed in all frequencies tested in either ear on days 1, 14 and 28 compared to initial values, and ABR threshold shifts ranged from –3 ± 5 dB (min.) to +5 ± 7 dB (max.). On day 28 after implantation, there were no significant differences of ABR threshold shifts between this and the implant groups, except for 6 kHz of the slow-release device. Therefore, the placebo implants, the slow-release and the fast-release beclomethasone implants appear suitable for further experiments.
Place and Personal Commitment In Teaching Environmental Ethics
Authors: Cafaro Philip 
Published: December 2004

AbstractThis essay, a personal account of teaching environmental ethics, advances two main points. First, focusing on local environmental issues makes for better classes. Teachers can take advantage of local environmental expertise at their institutions and in the wider community; local focus provides a good balance given philosophy's tendency to abstractness; students tend to feel more engaged and excited about the class. Second, environmental ethics classes should spend more time helping students articulate their own ethical positions and showing them how to act upon them. In this way, our classes will better prepare and inspire students to do right by nature.
Teaching the Land Ethic
Authors: Nelson Michael 
Published: December 2004

AbstractThis paper discusses the teaching of the Leopoldian Land Ethic in an environmental ethics class. The Leopoldian Land Ethic is arguably the most fully formulated and developed environmental ethic to date. Moreover, at least in North America, it is also the ethical reference point of choice for conservation workers both within and outside of government service, and thus it is particularly important that students who will pursue such careers are exposed to it. Although there are a number of ways to unpack the Land Ethic in a university environmental ethics classroom, and for more public audiences, this paper outlines one method that has been highly effective in both teaching settings over a long period of time.
Teaching Environmental Ethics: Non-indigenous Invasive Species As A Study of Human Relationships to Nature
Authors: Boorse Dorothy 
Published: December 2004

AbstractThis paper uses the question, "what ethical issues inform our response to nonindigenous invasive species?" as a basis to explore human relationships to nature in the context of teaching environmental ethics. While ecologists express increasing concern about the introduction of non-indigenous invasive species (NIS), the public is sometimes unaware of, or ambivalent about, the problems they cause. I argue that this ambivalence stems from conceptual problems—about human-nature relationships, about ethical conflict and about human behavior—that can be addressed in a course on environmental ethics. Such a course can look at NIS in the context of different ethical traditions, and the different bases for action (or not) with regard to NIS that such ethical traditions imply. I suggest ways to use NIS as case studies in either a science course or an environmental ethics course, to introduce fundamental questions and to explore basic worldviews with respect to humans and nature.
From Delight to Wisdom: Thirty Years of Teaching Environmental Ethics at Cornell
Authors: Skillen James , Baer Richard , Hitzhusen Gregory , Johnson Karl , Tantillo James 
Published: December 2004

AbstractIn this paper, the authors retrace the philosophy and method of Natural Resources 407, "Religion, Ethics, and the Environment," which has been continuously taught at Cornell University by the lead author since 1974. The works of Iris Murdoch, Stanley Hauerwas, Reinhold Niebuhr, Joseph Sax, and Thomas Merton are discussed, culminating in an aesthetic vision of environmental ethics as "praise for all things." The course aims more to foster a general moral maturity rather than to instill any any particular set of environmental behaviors in students, and the authors believe that such an aim makes a lasting contribution to environmental ethics.
On Honey Bees and Dynamic Server Allocation in Internet Hosting Centers
Authors: Nakrani Sunil , Tovey Craig 
Published: December 2004

Internet centers host services for e-banks, e-auctions and other clients. Hosting centers then must allocate servers among clients to maximize revenue. The limited number of servers, costs of reallocating servers, and unpredictability of requests make server allocation optimization difficult Based on the many similarities between server and honey bee colony forager allocation, we pro pose a new decentralized honey bee algorithm which dynamically allocates servers to satisfy request loads. We compare it against an omniscient optimality algorithm, a conventional greedy algorithm, and an algorithm that computes omnisciently the optimal static allocation. We evaluate performance on simulated request streams and commercial trace data Our algorithm performs better than static or greedy for highly variable request loads, but greedy can outperform it under low variability. Honey bee forager allocation, though suboptimal for static food sources, may possess a counterbalancing responsiveness to food source variability.
Electromagnetic detection of buried metallic objects using quad–quad conductivity
Authors: Huang Haoping , Won I. J. 
Published: December 2004

Apparent conductivity computed from in‐phase and quadrature components has been used successfully to detect buried metallic objects such as unexploded ordnance (UXO). The conductivity computation uses magnetic susceptibility calculated from the lowest‐frequency in‐phase data obtained at a specific sensor height. Over magnetic soils, however, the in‐phase component may fluctuate with varying sensor heights. Uncertainties in sensor height, common with handheld or cart‐mounted sensors in rough terrain, can produce errors in the computed magnetic susceptibility, which, in turn, causes errors in apparent conductivity.To overcome these limitations, we have developed an algorithm to compute the quad–quad apparent conductivity from the quadrature components at two frequencies. Our results show that the quad–quad technique has several advantages for detecting metal targets in magnetic terrains: it is (1) insensitive to the magnetic polarization currents; (2) it is immune to sensor motion over magnetic soil; and (3) it is biased to metal objects and can detect small and/or deep metal targets. The first two properties suppress the noise caused by magnetic terrain and sensor motion and thus yield a quiet background. The last property emphasizes metal objects as sought anomalies over geologic variations.
Diffraction imaging by focusing‐defocusing: An outlook on seismic superresolution
Authors: Khaidukov V. , Landa E. , Moser T. J. 
Published: December 2004

Diffractions always need more advertising. It is true that conventional seismic processing and migration are usually successful in using specular reflections to estimate subsurface velocities and reconstruct the geometry and strength of continuous and pronounced reflectors. However, correct identification of geological discontinuities, such as faults, pinch‐outs, and small‐size scattering objects, is one of the main objectives of seismic interpretation. The seismic response from these structural elements is encoded in diffractions, and diffractions are essentially lost during the conventional processing/migration sequence. Hence, we advocate a diffraction‐based, data‐oriented approach to enhance image resolution—as opposed to the traditional image‐oriented techniques, which operate on the image after processing and migration. Even more: it can be shown that, at least in principle, processing of diffractions can lead to superresolution and the recovery of details smaller than the seismic wavelength.The so‐called reflection stack is capable of effectively separating diffracted and reflected energy on a prestack shot gather by focusing the reflection to a point while the diffraction remains unfocused over a large area. Muting the reflection focus and defocusing the residual wavefield result in a shot gather that contains mostly diffractions. Diffraction imaging applies the classical (isotropic) diffraction stack to these diffraction shot gathers. This focusing‐muting‐defocusing approach can successfully image faults, small‐size scattering objects, and diffracting edges. It can be implemented both in model‐independent and model‐dependent contexts. The resulting diffraction images can greatly assist the interpreter when used as a standard supplement to full‐wave images.
A comparison between one‐way and two‐way wave‐equation migration
Authors: Mulder W. A. , Plessix R.‐E. 
Published: December 2004

Results for wave‐equation migration in the frequency domain using the constant‐density acoustic two‐way wave equation have been compared to images obtained by its one‐way approximation. The two‐way approach produces more accurate reflector amplitudes and provides superior imaging of steep flanks. However, migration with the two‐way wave equation is sensitive to diving waves, leading to low‐frequency artifacts in the images. These can be removed by surgical muting of the input data or iterative migration or high‐pass spatial filtering. The last is the most effective.Iterative migration based on a least‐squares approximation of the seismic data can improve the amplitudes and resolution of the imaged reflectors. Two approaches are considered, one based on the linearized constant‐density acoustic wave equation and one on the full acoustic wave equation with variable density. The first converges quickly. However, with our choice of migration weights and high‐pass spatial filtering for the linearized case, a real‐data migration result shows little improvement after the first iteration. The second, nonlinear iterative migration method is considerably more difficult to apply. A real‐data example shows only marginal improvement over the linearized case.In two dimensions, the computational cost of the two‐way approach has the same order of magnitude as that for the one‐way method. With our implementation, the two‐way method requires about twice the computer time needed for one‐way wave‐equation migration.
Wavelet‐transform‐based prestack multiscale Kirchhoff migration
Authors: Yu Zhou , McMechan George A. , Anno Phil D. , Ferguson John F. 
Published: December 2004

We propose a Kirchhoff‐style algorithm that migrates coefficients obtained by wavelet decomposition of seismic traces over time. Wavelet‐based prestack multiscale Kirchhoff migration involves four steps: wavelet decomposition of the seismic data, thresholding of the resulting wavelet coefficients, multiscale Kirchhoff migration, and image reconstruction from the multiscale images. The migration procedure applied to each wavelet scale is the same as conventional Kirchhoff migration but operates on wavelet coefficients. Since only the wavelet coefficients are migrated, the cost of wavelet‐based migration is reduced compared to that of conventional Kirchhoff migration. Kirchhoff migration of wavelet‐decomposed data, followed by wavelet reconstruction, is kinematically equivalent to and yields similar migrated signal shapes and amplitudes as conventional Kirchhoff migration when data at all wavelet scales are included.The decimation in the conventional discrete pyramid wavelet decomposition introduces a translation‐variant phase distortion in the wavelet domain. This phase distortion is overcome by using a stationary wavelet‐transform rather than the conventional discrete wavelet‐transform of the data to be migrated.A wavelet reconstruction operator produces a single composite broadband migrated space‐domain image from multiscale images. Multiscale images correspond to responses in different frequency windows, and migrating the data at each scale has a different cost. Migrating some, or only one, of the individual scale data sets considerably reduces the computational cost of the migration. Successful 2D tests are shown for migrations of synthetic data for a point‐diffractor model, a multilayer model, and the Marmousi model.
Nonlinear pairwise alignment of seismic traces
Authors: Liner Christopher L. , Clapp Robert G. 
Published: December 2004

Seismic trace alignment is a recurring need in seismic processing and interpretation. For global alignment via static shift, there are robust tools available, including crosscorrelation. However, another kind of alignment problem arises in applications as diverse as associating synthetic seismograms to field data, harmonizing P‐ and S‐wave data, residual NMO, and final multilevel flattening of common image gathers. These cases require combinations of trace compression, extension, and shift—all of which are time variant. The difficulty is to find a mapping between the traces that is in some senseoptimum. This problem is solved here using a modified form of the Needleman‐Wunsch algorithm, a global optimization method originally developed for aligning amino acid sequences in proteins. Applied to seismic traces, this algorithm provides a nonlinear mapping of one seismic trace onto another. The method extends to multitrace alignment since that problem can be broken down into a cascade of pairwise alignments. Seismic implementation of the Needleman‐Wunsch algorithm is a promising new tool for nonlinear alignment and flattening of seismic data.
Conserved asparagine residue 54 of α-sarcin plays a role in protein stability and enzyme activity
Authors: Siemer Ansgar , Masip Manuel , Carreras Nelson , García-Ortega Lucía , Oñaderra Mercedes , Bruix Marta , Martínez del Pozo Álvaro , G. Gavilanes José 
Published: December 2004

AbstractAsparagine 54 of α-sarcin is a conserved residue within the proteins of the ribotoxin family of microbial ribonucleases. It is located in loop 2 of the protein, which lacks repetitive secondary structure elements but exhibits a well-defined conformation. Five mutant variants at this residue have been produced and characterized. The spectroscopic characterization of these proteins indicates that the overall conformation is not changed upon mutation. Activity and denaturation assays show that Asn-54 largely contributes to protein stability, and its presence is a requirement for the highly specific inhibitory activity of these ribotoxins on ribosomes.
St. John's wort (Hypericum perforatum) counteracts cytokine-induced tryptophan catabolism in vitro
Authors: Winkler Christiana , Wirleitner Barbara , Schroecksnadel Katharina , Schennach Harald , Fuchs Dietmar 
Published: December 2004

AbstractSt. John's wort (Hypericum perforatum)is an ancient folk remedy that has antiviral and antibacterial properties. Anti-inflammatory effects of the plant have been described and the application ofH. perforatumextract as an effective antidepressant is well established. In this study we assayed the effect ofH. perforatumextract on cytokine-induced tryptophan degradation in human peripheral blood mononuclear cells. Simultaneously, changes in the production of the immune activation marker neopterin were monitored. Both these biochemical pathways are triggered by interferon-γ. Our results show that extracts ofH. perforatumstrongly down-regulate mitogen-mediated tryptophan degradation in a dose-dependent manner. This effect seems to be based on a suppressive activity ofH. perforatumon activated immunocompetent cells, resulting in a diminished production of interferon-γ. In line with this finding, neopterin synthesis was strongly down-regulated by the plant extract. Our results suggest that the reduction of tryptophan degradation byH. perforatummight be important in the action of the plant as an antidepressant.