bluuebunny/crossref_metadata_2025_split huggingface dataset:
Issues on the Seismic Retrofit of a Building near Resonant Response and Structural Pounding
Authors: Tena-Colunga Arturo , Del Valle Enrique , Pérez-Moreno Dalila 
Published: July 2003

Paper presents an analytical study on the possible application of commonly used retrofit schemes for an existing nine-story apartment building in Mexico City. The building, located in Mexico City's lake-bed region, was originally conceived as a RC waffle-flat slab structural system and was built in the late sixties. The building suffered important structural damage during the March 14, 1979 Petatlán Earthquake, primarily caused by structural pounding with neighboring structures due to its flexibility and resonant response with the ground. The building was retrofitted shortly after the Petatlán Earthquake with steel bracing in the direction of pounding. The retrofitted building survived the September 19, 1985 Michoacán Earthquake with light structural damage. Some evidence of pounding with one neighboring structure was again observed. Because of the chronic pounding problems with adjacent structures, which are separated eight to fifteen cm from the apartment building, it is felt that an additional upgrade of the structure may be needed for the safety of the building if a strong earthquake similar to the 1985 Michoacán Earthquake may strike Mexico City soon again. Different retrofit schemes were studied, which can be grouped as follows: a) weight reduction, b) column and waffle-slab jacketing, c) addition of energy dissipation devices, d) removal of top floors, e) replacement of diagonal bracing with newer bracing and, f) a combination of previous solutions. The effectiveness of the studied retrofit schemes is discussed by comparing their dynamic structural response with respect to the response of the actual retrofitted structure using nonlinear dynamic analyses for a postulated Ms=8.1 earthquake, as well as construction process, property value, and building use considerations. It is concluded that many aspects need to be evaluated in a seismic retrofit plan for a given building structure and often, the best alternative from the structural viewpoint may not be the best alternative overall.
Measured Response of Roof Diaphragms and Wall Panels in Tilt-Up Systems Subjected to Cyclic Loading
Authors: Fonseca Fernando S. , Wood Sharon L. , Hawkins Neil M. 
Published: July 2003

An experimental program was developed to study the strength and deformation capacity of tilt-up structures with plywood roof diaphragms. Two models of tilt-up systems were constructed and tested in the laboratory. The structures were representative of one-story warehouse construction in the western U.S. The overall dimensions of the two test specimens were the same; however, the number and distribution of reinforced concrete wall panels were varied. Each specimen was subjected to a series of lateral load reversals. Two aspects of the measured response of the test specimens are discussed in this paper: the in-plane displacements of the plywood roof diaphragm and the transverse response of the perimeter wall panels. The wall panels experienced nearly rigid-body rotation during the entire testing series, and the observed nonlinear response of the test specimens may be attributed to the inherent flexibility of the plywood diaphragm.
Analysis of Northridge Damaged Thirteen-Story WSMF Building
Authors: Maison Bruce F. , Kasai Kazuhiko 
Published: July 2003

The case study building experienced moment connection fractures and has instructure recorded response. Correlative analyses are performed using a probability approach to describe the connection rotational capacities. The Northridge calibrated model is then subjected to other scenario earthquake records. The main points include: -Northridge connection damage can be reasonably simulated using models that idealize the rotation capacities as random variables, -Many of the connection fractures occurred from beam moment demands that were less than the beam yield moments, -Vertical earthquake excitation and gravity loads did not play a major role in the connection fractures, -The damaged building can withstand another Northridge intensity quake, -Near-source ground motions from great quakes have the potential to collapse the building with pre-Northridge type connection details, and -Connection rotation capacity can make the difference between building survival or collapse during severe quakes.
Herbicide Resistant Plants, Production of
Authors: Songstad D.D. 
Published: July 2003

AbstractIntroductionResistance to Imidazolinone, Sulfonyl Urea, and Related HerbicidesResistance to Glutamine Synthetase Inhibitor HerbicidesResistance to Acetyl Coenzyme A Carboxylase Inhibiting HerbicidesResistance to Photosystem II Inhibiting HerbicidesResistance to 2,4‐D and Related HerbicidesGlyphosate‐Resistant PlantsUtilization of Herbicide ToleranceAcknowledgmentsBibliography
Analysis of Carbon Materials by X‐ray Photoelectron Spectroscopy and X‐ray Absorption Spectroscopy
Authors: Retzko I. , Unger W.E.S. 
Published: July 2003

AbstractSince hard coating such as ta:C films are of growing interest for protecting surfaces of industrial machines and high capacity tools against wear and friction or for biomedical applications, more information about the structure‐to‐property relation is required. Therefore, core level X‐ray photoelectron sprectroscopy and X‐ray absorption spectroscopy and spectromicroscopy are used to derive chemical information about selected carbon species.
NMR spiral surface microcoils: Applications
Authors: Gimi Barjor , Eroglu Sertac , Leoni Lara , Desai Tejal A. , Magin Richard L. , Roman Brian B. 
Published: July 2003

AbstractWe describe the use of planar submillimeter diameter radio frequency (RF) microcoils at 500 MHz (11.74 T) to image biologic samples, specifically late‐stage frog oocytes (typical diameter 750–1000 μm) and isolated rat pancreatic islets (typical diameter 150–200 μm). For the frog oocyte we obtained a 25 × 25 μm in‐plane resolution on a 100 μm slice in 34 min, and for the pancreatic islets we obtained a 14 × 14 μm in‐plane resolution on a 100‐μm slice in 68 min. These results demonstrate that it is possible to obtain images of living cells with high temporal and spatial resolution under conditions where viability in maintained and functional stimulation is possible. The extension of these studies to smaller diameter microcoils or arrays of microcoils may allow magnetic resonance imaging to be performed on individual cells in culture, and could lead to in vivo assessment of cell function within biocapsules or tissue implants. © 2003 Wiley Periodicals, Inc. Concepts Magn Reson Part B (Magn Reson Engineering) 18B: 1–8, 2003
Geometry comparisons of an 11‐T coaxial reentrant cavity (ReCav) coil
Authors: Beck B.L. , Jenkins K.A. , Fitzsimmons J.R. 
Published: July 2003

AbstractThe continual march to higher magnetic fields for MRI/S has brought about a change in RF coil methodology that incorporates the use of cavity designs. One such design, the ReCav coil, has shown improvement in signal‐to‐noise (SNR) over standard low‐pass birdcages. This work studies the relationship between cavity geometry and coil performance. Five variations of the ReCav were built where either the diameter ratio between the inner and outer cylinders or the extent of reentrant wall were varied. The Q‐damping and SNR were measured for each design. It is shown that the reentrant wall in the ReCav plays an important role in improving the performance of the coil. © 2003 Wiley Periodicals, Inc. Concepts Magn Reson Part B (Magn Reson Engineering) 18B: 24–27, 2003
2‐D full wave solution for the analysis and design of birdcage coils
Authors: Spence Dan K. , Wright Steven M. 
Published: July 2003

AbstractA simple 2‐D full wave model for the birdcage coil is described that includes the effects of shields, lossy layered media, and finite leg widths. This model has been implemented in Matlab, which provides a simple user interface. Using this model, various coil parameters such as signal‐to‐noise ratio (SNR), magnetic field homogeneity, magnetic field magnitude, etc. can be computed quickly. The efficiency of this model allows optimization of the coil geometry for particular applications. A method for finding the optimal coil radius in terms of SNR and homogeneity, given shield and sample radii, is presented. © 2003 Wiley Periodicals, Inc. Concepts Magn Reson Part B (Magn Reson Engineering) 18B: 15–23, 2003.
Application of artificial neural network methods in HTS RF coil design for MRI
Authors: Pan Hui , Shen Gary X. 
Published: July 2003

AbstractThis article presents a new method of simulating high‐temperature superconducting (HTS) RF coils using an electromagnetically trained artificial neural network (EM‐ANN). This design is based on a spiral planar coil with distributed capacitance fabricated with Y1Ba2Cu3O7 (YBCO) films. Simulation time with this new method can be reduced to only one millionth of the time required by the commercial electromagnetic software programme HP Momentum. The new method can also exploit the properties of an artificial neural network by providing an inverse algorithm based on a resonant frequency input to derive other properties of an RF coil. This inverse algorithm using EM‐ANN is easier, faster, and more interactive than the traditional “moment method.” The simulation results also show excellent agreement with experimental measurements, with a margin of error of less than 3%. © 2003 Wiley Periodicals, Inc. Concepts Magn Reson Part B (Magn Reson Engineering) 18B: 9–14, 2003
Characterization of lacZ‐expressing cells in the gut of embryonic and adult DβH‐nlacZ mice
Authors: Stewart Ashley L. , Anderson Richard B. , Young Heather M. 
Published: July 2003

AbstractIn mice that express lacZ under the control of a human dopamine β‐hydroxylase gene promoter (DβH‐nlacZ mice), the nuclei of enteric neurons express the transgene, as shown by the presence of β‐galactosidase (β‐gal) staining (Mercer et al. [1991] Neuron 7:703–716). The transgene is also expressed by neural crest‐derived cells in the developing gut before their differentiation into neurons or glial cells (Kapur et al. [1992] Development 116:167–175). However, the cell types expressing the DβH‐nlacZ transgene within the developing and adult gut have not been fully characterized. Whole‐mount preparations of embryonic and adult gut were processed for histochemistry or immunohistochemistry to reveal β‐gal plus markers of undifferentiated neural crest cells (in embryos) or enteric neurons (in adults). In embryonic mice, over 90% of undifferentiated neural crest‐derived cells (identified using antibodies to p75) were β‐gal+. Importantly, crest‐derived cells at the migratory wavefront were all β‐gal+. In adult mice, only a subpopulation of enteric neurons was β‐gal+, while glial cells showed no β‐gal staining. Considerable variation was observed between the small intestine and colon in the proportion of myenteric neurons that showed β‐gal staining. We examined whether known classes of enteric neurons varied in their expression of DβH‐nlacZ. In the myenteric plexus of the jejunum and colon, large calretinin+ neurons did not express lacZ, suggesting that the incomplete penetrance of the DβH‐nlacZ transgene observed in adult mice is not random. We conclude that the DβH‐nlacZ transgene provides a reliable marker for examining the colonization of the developing gut by neural crest cells. However, in adult mice, there is variation between mice, between gut regions, and between different classes of enteric neurons in the expression of the transgene. J. Comp. Neurol. 464:208–219, 2003. © 2003 Wiley‐Liss, Inc.
Vocal circuitry inXenopus laevis: Telencephalon to laryngeal motor neurons
Authors: Brahic Catherine J. , Kelley Darcy B. 
Published: July 2003

AbstractSexually differentiated calling patterns ofXenopus laevisare conveyed to the vocal organ by a dedicated neuromuscular system. Here, we define afferents to vocal motor neurons and determine whether the connectivity of the vocal pathway is sexually differentiated. The use of fluorescent dextran amines and the isolated brain preparation readily permitted identification of anterograde and retrograde connectivity patterns. The whole‐mount preparation allowed us to observe projections in their entirety, including cells of origin of a projection (for retrograde projections), terminal fields (for anterograde connections), and fiber tracts. Major findings are the confirmation of a robust and reciprocal connection between cranial nucleus (n.) IX‐X and the pretrigeminal nucleus of the dorsal tegmental area of the medulla (DTAM) as well as between DTAM and the ventral striatum (VS). Newly revealed is the extensive connectivity between the rostral subdivision of the dorsal nucleus raphe (rRpd) and candidate vocal nuclei. In contrast to previous results using peroxidase, we did not observe dramatic sex differences in connectivity, although some connections were less robust in female than in male brains. Some retrograde connections previously observed (e.g., anterior preoptic area to DTAM) were not confirmed. Plausible hypotheses are that a set of rhombencephalic neurons located in DTAM, the inferior reticular formation and n.IX‐X are responsible for generating patterned vocal activity, that activity is modulated by neurons in rRpd, and that activity in VS (particularly that evoked by conspecific calls), together with effects of steroid hormones at many sites in the vocal circuit, contribute to the initiation of calling. J. Comp. Neurol. 464:115–130, 2003. © 2003 Wiley‐Liss, Inc.
Sorting and convergence of primary olfactory axons are independent of the olfactory bulb
Authors: St. John James A. , Clarris Heidi J. , McKeown Sonja , Royal Stephanie , Key Brian 
Published: July 2003

AbstractPrimary olfactory axons expressing the same odorant receptor gene sort out and converge to fixed sites in the olfactory bulb. We examined the guidance of axons expressing the P2 odorant receptor when they were challenged with different cellular environments in vivo. In the mutant extratoes mouse, the olfactory bulb is lacking and is replaced by a fibrocellular mass. In these animals, primary olfactory axons form glomerular‐like loci despite the absence of normal postsynaptic targets. P2 axons are able to sort out from other axons in this fibrocellular mass and converge to form loci of like axons. The sites of these loci along mediolateral and ventrodorsal axes were highly variable. Similar convergence was observed for larger subpopulations of axons expressing the same cell surface carbohydrates. The sorting out and convergence of like axons also occurred during regeneration following bulbectomy. Olfactory axon behaviour in these models demonstrates that sorting and convergence of axons are independent of the target, which instead provides distinct topographic cues for guidance. J. Comp. Neurol. 464:131–140, 2003. © 2003 Wiley‐Liss, Inc.
Differential patterns of glial fibrillary acidic protein‐immunolabeling in the brain of adult lizards
Authors: Ahboucha Samir , Laalaoui Abdelhadi , Didier‐Bazes Marianne , Montange Michelle , Cooper Howard Michael , Gamrani Halima 
Published: July 2003

AbstractThe present study describes by means of immunohistochemistry the comparative distribution of glial fibrillary acidic protein (GFAP)‐positive cells in the forebrain and midbrain of three species of lizards: Eumeces algeriensis, Scincoidae; Agama impalearis, Agamidae; Tarentola mauritanica, Gekkonidae. In the species studied, the different types and proportions of glial cells expressing GFAP showed considerable variation. These cells include radial glia, oval cells, tanycytes, ependymocytes, glia limitans, and astrocytes. In Eumeces, astrocytes are particularly abundant and their processes form numerous perivascular end‐feet; in addition well‐differentiated ependymal cells and glia limitans express GFAP. These mature glial features are concordant with the relatively advanced phylogenetic level of Eumeces. In Tarentola, relatively few GFAP‐expressing glial cells are observed, consisting mainly of radial glia and tanycytes. These features indicate a relatively immature state of the glial cell populations in this species. In Agama, GFAP‐immunostained cells are confined to the periventricular and subpial brain areas; the ventricular lining contains numerous GFAP‐immunopositive tanycytes and well‐differentiated glia limitans. This pattern indicates that the glial cell profile in Agama exhibits characteristics intermediate between Eumeces and Tarentola, a feature which is discordant with the relatively primitive phylogenetic level of Agamidae compared to Gekkonidae. Together, the results of the present study provide novel data on the characterization of GFAP‐expressing cell populations in different species of lizards. We suggest that the different glial patterns observed in the lizard brain correlates with developmental and functional aspects. J. Comp. Neurol. 464:159–171, 2003. © 2003 Wiley‐Liss, Inc.
Overlapping distributions of orexin/hypocretin‐ and dopamine‐β‐hydroxylase immunoreactive fibers in rat brain regions mediating arousal, motivation, and stress
Authors: Baldo Brian A. , Daniel Roger A. , Berridge Craig W. , Kelley Ann E. 
Published: July 2003

AbstractA double‐label immunohistochemical study was carried out to investigate overlap between dopamine‐β‐hydroxylase (DβH) ‐immunopositive projections and the projections of hypothalamic neurons containing the arousal‐ and feeding‐related peptide, orexin/hypocretin (HCRT), in rat brain. Numerous intermingled HCRT‐immunopositive and DβH‐immunopositive fibers were seen in a ventrally situated corridor extending from the hypothalamus to deep layers of the infralimbic cortex. Both fiber types avoided the nucleus accumbens core, caudate putamen, and the globus pallidus. In the diencephalon, overlap was observed in several hypothalamic areas, including the perifornical, dorsomedial, and paraventricular nuclei, as well as in the paraventricular thalamic nucleus. Intermingled HCRT‐containing and DβH‐containing fibers extended from the hypothalamus into areas within the medial and central amygdala, terminating at the medial border of the lateral subdivision of the central nucleus of the amygdala. Dense overlap between the two fiber types was also observed in the periaqueductal gray, particularly in the vicinity of the dorsal raphe, as well as (to a lesser extent) in the ventral tegmental area, the retrorubral field, and the pedunculopontine tegmental nucleus. Hypocretin‐containing cell bodies, located in the perifornical and lateral hypothalamus, were embedded within a dense plexus of DβH‐immunopositive fibers and boutons, with numerous cases of apparent contacts of DβH‐containing boutons onto HCRT‐immunopositive soma and dendrites. HCRT‐containing fibers were observed amid the noradrenergic cells of the locus coeruleus, and in the vicinity of the A1, A2, and A5 cell groups. Hence, the projections of these two arousal‐related systems, originating in distinctly different parts of the brain, jointly target several forebrain regions and brainstem monoaminergic nuclei involved in regulating core motivational processes. J. Comp. Neurol. 464:220–237, 2003. © 2003 Wiley‐Liss, Inc.
Interference with anoikis‐induced cell death of dopamine neurons: Implications for augmenting embryonic graft survival in a rat model of Parkinson's disease
Authors: Marchionini Deanna M. , Collier Timothy J. , Camargo Maria , McGuire Susan , Pitzer Mark , Sortwell Caryl E. 
Published: July 2003

AbstractOne promising therapy for the treatment of Parkinson's disease is transplantation of embryonic ventral mesencephalic tissue. Unfortunately, up to 95% of grafted cells die, many via apoptosis. In this study we attempted to prevent anoikis‐induced cell death, which is triggered during the preparation of cells for grafting, and examine the impact on graft viability and function. We utilized the extracellular matrix molecule tenascin‐C (tenascin) and an antibody (Ab) to the cell adhesion molecule L1 to specifically mimic survival signals induced by cell–matrix and cell–cell interactions. In vitro, both tenascin‐ and L1 Ab‐treated cultures doubled the number of tyrosine hydroxylase immunoreactive (THir) neurons compared to control. Additionally, cell survival assays determined that tenascin and L1 Ab‐treated cell suspensions yielded more metabolically active and fewer dead cells than control suspensions. In contrast to the culture results, tenascin‐ and L1 Ab‐treated mesencephalic grafts did not yield an increase in the number of THir neurons using our standard grafting paradigm (3 μl of 100,000 cells/μl). However, under low‐density conditions (3 μl of 3,000 cells/μl), tenascin augmented grafted THir neuron survival. These findings are consistent with the view that cell density can dramatically influence the degree of stress placed on THir neurons and consequently affect the success of survival strategies in vivo. In conclusion, pretreatment with tenascin may prove beneficial to prevent anoikis in dilute cell suspension grafts, while long‐term in vivo delivery methods need to be explored to determine if L1 can prevent anoikis in grafts of mesencephalic dopamine neurons after transplantation. J. Comp. Neurol. 464:172–179, 2003. © 2003 Wiley‐Liss, Inc.
Translocation of presynaptic delta opioid receptors in the ventrolateral periaqueductal gray after swim stress
Authors: Commons Kathryn G. 
Published: July 2003

AbstractImmunolabeling for the delta opioid receptor (DOR) is localized primarily to axon terminals in the ventrolateral periaqueductal gray (vlPAG). However, rather than on the plasma membrane, DOR immunoreactivity is usually located within the cytoplasmic compartment, often associated with dense‐core vesicles. In this study, the hypothesis that a behavioral stimulus, a cold water swim stress (3 minutes at 4°C; CWSS), could initiate the translocation of the DOR was tested. The subcellular distribution of DOR was examined using a preembedding immunogold‐labeling method and ultrastructural analysis in control rats and in rats that had a CWSS. In both cases, dense‐core vesicles associated with DOR labeling were often within 100 nm of the plasma membrane. When the dense‐core vesicles were near the plasma membrane, sometimes electron‐dense “tethers” appeared between the vesicle and the plasma membrane. However, in rats exposed to CWSS, there was a decrease in immunolabeling associated with dense‐core vesicles that were near the plasma membrane and a significant increase in DOR immunoreactivity associated with the plasma membrane. In addition, there was a significant increase in the fraction of DOR immunoreactivity associated with large clear‐core vesicles; possibly early endosomes. Moreover, after a CWSS, dense‐core vesicles containing DOR immunoreactivity could be visualized fusing with the plasma membrane of synaptic boutons. These data suggest the involvement of DOR in the vlPAG in the behavioral response to CWSS. Furthermore, the results support the hypothesis that the cell surface distribution of presynaptic receptors can be regulated in an activity‐dependent manner by virtue of transport via dense‐core vesicles. J. Comp. Neurol. 464:197–207, 2003. © 2003 Wiley‐Liss, Inc.