bluuebunny/crossref_metadata_2025_split huggingface dataset:
Motions of rigid bodies and criteria for overturning by earthquake excitations
Authors: Ishiyama Yuji 
Published: March 2007

AbstractThis investigation deals with motions of rigid bodies on a rigid floor subjected to earthquake excitations, and criteria for overturning of the bodies.In order to study any motions of a body in a plane, the motions are classified into six types, i.e. (1) rest, (2) slide, (3) rotation, (4) slide rotation, (5) translation jump and (6) rotation jump. Then, the following are studied: the equations of motion, transitions of motion, and motions after impact between the body and the floor. One of the features of this investigation is the introduction of the tangent restitution coefficient which enables us to estimate the magnitude of the tangent impulse at the instant of impact.A computer program was developed to simulate the motions of bodies subjected to horizontal and vertical ground motions, numerically solving the non‐linear equations of motion.Several types of simulation were carried out and the following conclusions were found. The coefficient of friction must be greater than the breadth—height‐ratio in order for the body to rock. The motions after impact from translation jump are greatly influenced by the normal and tangent restitution coefficients. As criteria for overturning of bodies, at least two factors must be taken into account: the horizontal acceleration and the velocity of the floor. Then it is possible to estimate the motions of the floor from the overturning of bodies in a more reliable manner than before.
Vibration of beams on partial elastic foundations
Authors: Doyle Paul F. , Pavlovic Milija N. 
Published: March 2007

AbstractThe natural response of a beam or pile having only a portion of its span supported by an elastic foundation is investigated for the two cases when both ends are either simply supported or free. The derivation of the shape functions and the computed natural frequencies are compared with the extreme cases where the element is either completely supported by, or fully detached from, the elastic foundation.
Fatigue life of critical members in a railway truss bridge
Authors: Garg Vijay K. , Chu Kuang‐Han , Wiriyachai A. 
Published: March 2007

AbstractThe fatigue life of critical members, such as hangers, floor‐beams and stringers in a single track, open deck railroad truss bridge, was investigated for various unit freight trains, operating at different speeds. A partial bridge model was used, along with a three‐car train, to determine the stress cycles. For determining the fatigue lives of critical members, four fully‐loaded trains per day were assumed to pass over the bridge. Each train was assumed to consist of one hundred 70‐ton cars or seventy 100‐ton cars. The 100‐ton freight cars cause large stress ranges, and consequently shorter fatigue lives than the 70‐ton freight cars. For the hundred‐car train, with 70‐ton and 100‐ton cars mixed in various proportions, the fatigue lives became shorter as the percentage of 100‐ton cars in the consist was increased. The impact percentages were also studied.
An FFT algorithm for structural dynamics
Authors: Hall John F. 
Published: March 2007

AbstractA Fast Fourier Transform algorithm (FFT) is described which is especially suited for structural dynamics. The routine incorporates several features selected from many variations of the original Cooley and Tukey1 algorithm with the goal of making the most efficient use of computer time and storage while maintaining simplicity. Some introductory material to Fourier transform techniques and a description of the original algorithm are also included. In addition, the source listing of the subroutine FFT is reproduced.
Free‐field response from inclined SH‐waves and love‐waves
Authors: Wolf John P. , Obernhuber Pius 
Published: March 2007

AbstractTo identify the key features of the free‐field response for antiplane motion, a vast parametric study is performed, varying the location of the control point, the nature of the wave pattern and the site properties. Harmonic and transient seismic excitations for a site consisting of a layer on bedrock and an actual soft site and a rock site are investigated.When the control point is selected at the outcrop of the bedrock, the amplification of the motion to the free surface of the site depends on the angle of incidence of the incoming wave in the bedrock. Vertically incident, inclined SH‐waves and Love‐waves result in a very similar variation of the motion with depth. In contrast to Love‐waves the attenuation of the motion in the horizontal direction for inclined body waves depends on the damping of only the bedrock. Love‐waves thus attenuate more strongly than body waves, especially for soft sites and in the higher‐frequency range. Generally, higher Love‐modes attenuate less than the first. To determine the seismic input motion for a structure at a soft site, it seems sufficient to examine only extremely shallow body waves. For a rock site, however, Love‐waves should be investigated.
Vertical seismic behaviour of suspension bridges
Authors: Abdel‐Ghaffar A. M. , Rubin L. I. 
Published: March 2007

AbstractThe vertical response of suspension bridges to multi‐support seismic excitations is investigated. A frequency‐domain random‐vibration approach is utilized to take into account not only the differences in ground motion inputs, but also the correlation among the various input motions. The earthquake response of the Golden Gate Suspension Bridge, California, is analysed. The ground motion inputs were taken from an array of time histories recovered from the Imperial Valley, California, earthquake (ML = 6.6) of 15 October 1979. Mean square displacement, stress and cable tension responses are obtained. An estimation of the expected peak response is made by comparing existing methods to the results of a time‐domain analysis; it was found that a peak factor of 3.5 times the r.m.s. response is a good estimate of the expected peak response for this multiple‐input seismic problem.
Transient flexural vibrations of an elastic column supported by an elastic half‐space
Authors: Wada H. 
Published: March 2007

AbstractAn analysis is presented of the transient flexural vibrations of an elastic column supported by an elastic half‐space under the condition that an arbitrarily shaped free‐field lateral acceleration and displacement are given as inputs. Applying Laplace transformations with respect to time and numerical inverse Laplace transformations, the time histories of the column acceleration at the interface and free end, and the column and half‐space displacement distributions are obtained. After the input free‐field acceleration terminates, slightly damped and almost harmonically variable acceleration is observed. The acceleration frequency after the disappearance of the input acceleration nearly coincides with the resonant frequency of the system. The slight damping with the first resonant frequency, even if the half‐space is soft compared with the column, is characteristic of the transient flexural vibrations of a column supported by a half‐space. Such a phenomenon is not typical of the transient longitudinal vibration problem. Therefore, it may be concluded: when buildings and structures are subjected to an earthquake or an explosive force, their flexural vibrations will continue with their first resonant frequencies, even if their foundations are soft.
Temporal‐spatial dynamics in oligodendrocyte and glial progenitor cell numbers throughout ventrolateral white matter following contusion spinal cord injury
Authors: Rabchevsky Alexander G. , Sullivan Patrick G. , Scheff Stephen W. 
Published: March 2007

AbstractThe aim of this study was to systematically determine the spatial distribution of oligodendrocytes (CC1+) and glial progenitor cells (NG2+) throughout the ventral lateral funiculi (VLF) of adult rat thoracic spinal cord white matter over the course of spontaneous hindlimb locomotor recovery following moderate contusion injury. We used the optical fractionator technique to establish an unbiased estimate of total CC1+ and NG2+ cell numbers throughout equivalent segments of VLF from normal and injured spinal cords at designated time points. The results demonstrated a greater than 60% loss of oligodendrocytes and a 50% increase in NG2+ cells 2 days postinjury. Subsequently, there was a significant increase in oligodendrocytes 7 days postinjury that continued throughout the time course of our experiments (42 days) when the total numbers recovered to 80% of controls. Conversely, NG2+ cell numbers progressively declined after 2 days postinjury but remained significantly higher than controls throughout the experiments. The pattern of acute loss and repopulation of oligodendrocytes in the VLF paralleled the initial recovery of hindlimb weight‐bearing function. Whether such improvement is directly related to NG2+ cell differentiation into functional oligodendrocytes is uncertain. However, of critical importance is that significant cellular dynamics occurred primarily distal to the injury, and these changes were mirrored by significant alterations in the expression of mature myelin proteins. This infers that site‐specific genetic or cellular interventions designed to enhance locomotor recovery by fostering remyelination of spared and/or newly established relay circuits may need to target not only the injury site but also rostrocaudal regions. © 2007 Wiley‐Liss, Inc.
Positive and negative modulation of word learning by reward anticipation
Authors: Callan Daniel E. , Schweighofer Nicolas 
Published: March 2007

AbstractRecent evidence from neuroscience indicates that the anticipation of external rewards may enhance declarative memory consolidation by increasing dopaminergic‐modulated plasticity in the hippocampus. A number of studies in psychology, however, have shown that external rewards may have null, or even negative, effects on learning. To shed light on this issue, we developed a novel task, in which native Japanese speakers were rewarded to learn unknown English words inside a functional MRI scanner. Rewards had no effect on recall performance unless we used a rating of reward‐induced anxiety as a covariate. In this case, for highly rewarded words, we found a negative correlation between recall performance and anxiety ratings. For those words, high recall performance and low anxiety ratings were associated with enhanced activity in the midbrain dopaminergic centers, the hippocampus, and the amygdala. On the other hand, low recall performance and high anxiety ratings were associated with enhanced activity in the anterior cingulate and middle frontal gyrus, brain regions that have been shown to be involved with anxiety and divided attention, respectively. A connectivity analysis indicated positive functional connectivity between the midbrain dopaminergic centers and both the hippocampus and the amygdala, as well as negative connectivity between the anterior cingulate and the amygdala. Thus, both our behavioral and imaging results suggest that the anticipation of rewards can, depending on the individual level of reward‐induced anxiety, have either a beneficial effect or a negative effect on word learning. Hum Brain Mapp 2008. © 2007 Wiley‐Liss, Inc.
Cancer cachexia syndrome in head and neck cancer patients: Part II. Pathophysiology
Authors: George Jonathan , Cannon Trinitia , Lai Victor , Richey Luther , Zanation Adam , Neil Hayes D. , Shores Carol , Guttridge Denis , Couch Marion 
Published: March 2007

AbstractCancer cachexia is a morbid wasting syndrome common among patients with head and neck cancer. While its clinical manifestations have been well characterized, its pathophysiology remains complex. A comprehensive literature search on cancer cachexia was performed using the National Library of Medicine's PubMed. The Cochrane Library and Google search engine were also used. Recent evidence and new concepts on the pathophysiology of cancer cachexia are summarized. Targeted therapies are presented, and new concepts are highlighted. Cancer cachexia is characterized by complex, multilevel pathogenesis. It involves up‐regulated tissue catabolism and impaired anabolism, release of tumor‐derived catabolic factors and inflammatory cytokines, and neuroendocrine dysfunction. These culminate to create an energy‐inefficient state characterized by wasting, chronic inflammation, neuroendocrine dysfunction, and anorexia. © 2007 Wiley Periodicals, Inc. Head Neck, 2007
Tunisian radish extract (Raphanus sativus) enhances the antioxidant status and protects against oxidative stress induced by zearalenone in Balb/c mice
Authors: Salah‐Abbès Jalila Ben , Abbès Samir , Ouanes Zouhour , Houas Zohra , Abdel‐Wahhab Mosaad A. , Bacha Hassen , Oueslati Ridha 
Published: March 2007

AbstractRadish (Raphanus sativus) is a food plant known worldwide. From antiquity it has been used in folk medicine as a natural drug against many toxicants. Zearalenone (zen) is a non‐steroidal estrogenic mycotoxin present in corn and food mixture for farm animals and it is hepatotoxic, hematotoxic, immunotoxic, nephrotoxic and genotoxic. The objectives of the present study were to assess the biological activity of radish extract and to evaluate the protective role of radish extract against the toxicity of zen in female Balb/c mice. Animals were divided into seven groups and treated orally for 10 days as follows: a control, an olive oil group, groups treated with radish extract alone (5, 10 and 15 mg kg−1 b.w.), a group treated with zen (40 mg kg−1 b.w.) and a group treated with zen plus the lowest dose of radish extract. The results indicate that radish extract improved the antioxidant status and had no significant effects on hematological and biochemical parameters tested or histology of the liver and kidney. Treatment with zen results in a significant increase in ALT, AST, ALP, BILT, BILD, CRE accompanied with significant changes in most of hematological parameters and the antioxidant enzyme activities, co‐treatment of zen and the radish extract results in a significant reestablishment of hematological, serum biochemical parameters, and the histology of the liver and kidney. These findings suggest that radish extract is safe and can be overcome or, at least, significantly diminish zen effects. Copyright © 2007 John Wiley & Sons, Ltd.
Nondegradable hydrogels for the treatment of focal cartilage defects
Authors: Maher S.A. , Doty S.B. , Torzilli P.A. , Thornton S. , Lowman A.M. , Thomas J.D. , Warren R. , Wright T.M. , Myers E. 
Published: March 2007

AbstractNondegradable materials have long been suggested for the treatment of articular cartilage defects; however, the mechanics of the implant/tissue system necessary to ensure long‐term function are unknown. The objective of this study was to explore the performance of nondegradable hydrogel implants in cartilage defects. Our hypothesis was that the structural integrity of the implant and surrounding tissue would be influenced by the compressive modulus of the material used, and that superior results would be obtained with the implantation of a more compliant material. Poly(vinyl alcohol)–poly(vinyl pyrrolidone) hydrogel implants of two different moduli were implanted into osteochondral defects in a rabbit model. Six‐month postoperative histological and mechanical data were used to assess the wear and fixation of the implants. The compliant implants remained well fixed and a thin layer of soft tissue grew over the surface of the implants. However, gross deformation of the compliant implants occurred and debris was evident in surrounding bone. The stiffer implants were dislocated from their implantation site, but with no accompanying evidence of debris or implant deformation. Our hypothesis that superior results would be obtained with implantation of a more compliant material was rejected; a compromise between the wear and fixation properties dependent on modulus was found. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res 2007
Effects of Vitaxin®, a novel therapeutic in trial for metastatic bone tumors, on osteoclast functions in vitro
Authors: Gramoun Azza , Shorey Seema , Bashutski Jill D. , Dixon S. Jeffrey , Sims Stephen M. , Heersche Johan N. M. , Manolson Morris F. 
Published: March 2007

AbstractThe integrin αvβ3 mediates cell–matrix interactions. Vitaxin®, a humanized monoclonal antibody that blocks human and rabbit αvβ3 integrins, is in clinical trials for metastatic melanoma and prostate cancer. αvβ3 is the predominant integrin on osteoclasts, the cells responsible for bone resorption in health and disease. Here, we report the first investigation of Vitaxin's effects on osteoclast activity. Vitaxin (100–300 ng/ml) decreased total resorption by 50%, but did not alter resorptive activity per osteoclast. Vitaxin (300 ng/ml) decreased osteoclast numbers on plastic by 35% after 48 h. Similarly, attachment after 2 h was reduced by 30% when osteoclasts were incubated with Vitaxin (300 ng/ml) for 25 min prior to plating; however, the rate of fusion of osteoclast precursors in Vitaxin‐treated and control groups was equal. Using time‐lapse microscopy, we evaluated the effect of Vitaxin on osteoclast morphology and found a significant reduction in osteoclast planar area only when cells were pretreated with macrophage colony stimulating factor (M‐CSF). Extracellular Ca2+ and M‐CSF have opposite effects on αvβ3 conformation. Elevation of extracellular Ca2+ eliminated the inhibitory effect of Vitaxin on osteoclast attachment. In contrast, the effect of Vitaxin was enhanced in cells pretreated with M‐CSF. This action of M‐CSF was suppressed by the phosphatidylinositol 3‐kinase (PI3‐kinase) inhibitor wortmannin, suggesting that M‐CSF increases Vitaxin's inhibitory effect by inside‐out activation of αvβ3. In conclusion, Vitaxin decreases resorption by impairing osteoclast attachment, without affecting osteoclast formation and multinucleation. Our data also show that Vitaxin's inhibitory effects on osteoclasts can be modulated by factors known to alter the conformation of αvβ3. J. Cell. Biochem. 102: 341–352, 2007. © 2007 Wiley‐Liss, Inc.
Serum osteopontin, an enhancer of tumor metastasis to bone, promotes B16 melanoma cell migration
Authors: Hayashi Chikako , Rittling Susan , Hayata Tadayoshi , Amagasa Teruo , Denhardt David , Ezura Yoichi , Nakashima Kazuhisa , Noda Masaki 
Published: March 2007

AbstractTumor malignancy is associated with several features such as proliferation ability and frequency of metastasis. Since tumor metastasis shortens patients' lifetime, establishment of therapy for anti‐metastasis is very important. Osteopontin (OPN), which abundantly expressed in bone matrix, is involved in cell adhesion, migration, extracellular matrix (ECM) invasion and cell proliferation via interaction with its receptor, that is, αvβ3 integrin. OPN is believed to be a positive regulator of tumor metastasis in vivo. However, how OPN regulates metastasis is largely unknown. Here, we explore the role of OPN in cell migration. Serum from wild‐type mice induced cell migration of B16 melanoma cells, while serum from OPN‐deficient mouse suppressed this event. The presence of recombinant OPN significantly enhanced cell migration compared to albumin containing medium. OPN‐induced cell migration was suppressed by inhibiting the ERK/MAPK pathway indicating that OPN‐induced cell migration depends on this pathway. Overexpression of OPN in these cancer cells per se promoted cell proliferation and tended to increase B16 cell migration suggesting that OPN promotes bone metastasis by playing dual roles both in host microenvironment and in tumor cell itself. In conclusion, the elevated OPN expression in host tissue and tumor cell itself promotes tumor cell migration reading to tumor metastasis, suggesting that neutralization of OPN‐induced signal might be effective in suppression of tumor metastasis. J. Cell. Biochem. 101: 979–986, 2007. © 2007 Wiley‐Liss, Inc.
Renaut bodies in nerves of the trunk of the African elephant, Loxodonta africana
Authors: Witter Kirsti , Egger Gunter F. , Boeck Peter 
Published: March 2007

AbstractRenaut bodies are loosely textured, cell‐sparse structures in the subperineurial space of peripheral nerves, frequently found at sites of nerve entrapment. The trunk of the elephant is a mobile, richly innervated organ, which serves for food gathering, object grasping and as a tactile organ. These functions of the trunk lead to distortion and mechanical compression of its nerves, which can therefore be expected to contain numerous Renaut bodies. Samples of the trunk wall of an adult African elephant (Loxodonta africana) were examined histologically using conventional staining methods, immunohistochemistry, and lectin histochemistry. Architecture of nerve plexuses and occurrence of Renaut bodies in the elephant trunk were compared with those in tissues surrounding the nasal vestibule of the pig. Prominent nerve plexuses were found in all layers of the elephant trunk. Almost all (81%) nerve profiles contained Renaut bodies, a basophilic, discrete subperineurial layer resembling cushions around the nerve core. In contrast, Renaut bodies were seen in only 15% of nerve profiles in the porcine nasal vestibule. Within Renaut bodies, fusiform fibroblasts and round, ruff‐like cells were placed into a matrix of acidic glycosaminoglycans with delicate collagen and very few reticular fibers. The turgor of this matrix is thought to protect nerves against compression and shearing strain. Renaut bodies are readily stained with alcian blue (pH 2.5) favorably in combination with immunohistochemical markers of nerve fibers. They should be regarded as a physiological response to repeated mechanical insults and are distinct from pathological alterations. alterations. J. Morphol., 2007. © 2007 Wiley‐Liss, Inc.
Osteology and myology of the wing of the Emu (Dromaius novaehollandiae), and its bearing on the evolution of vestigial structures
Authors: Maxwell Erin E. , Larsson Hans C.E. 
Published: March 2007

AbstractEmus have reduced their wing skeleton to only a single functional digit, but the myological changes associated with this reduction have never been properly described. Moreover, the intraspecific variability associated with these changes has not previously been examined, dissections having been restricted in the past to only one or two individuals. In this paper, the myology and osteology of the Emu wing is described for a sample of five female birds. The Emu showed a marked reduction in the number of muscles in the wing, even compared with other ratites. Many wing muscles showed diversity in structure, origin and insertion sites, number of heads, as well as presence–absence variation. This variability dramatically exceeds that found in flying birds. Evolutionary theory predicts that relaxed selection on vestigial organs should allow more variation to persist in the population, and corresponds to what is observed here. A large amount of fluctuating asymmetry was also detected, indicating reduced canalization of the wing during development. J. Morphol. © 2007 Wiley‐Liss, Inc.