bluuebunny/crossref_metadata_2025 huggingface dataset:
Cytotoxic effects of Gemcitabine-loaded liposomes in human anaplastic thyroid carcinoma cells
Authors: Celano Marilena , Calvagno Maria Grazia , Bulotta Stefania , Paolino Donatella , Arturi Franco , Rotiroti Domenicoantonio , Filetti Sebastiano , Fresta Massimo , Russo Diego
Published: September 2004

Background

Identification of effective systemic antineoplastic drugs against anaplastic thyroid carcinomas has particularly important implications. In fact, the efficacy of the chemotherapeutic agents presently used in these tumours, is strongly limited by their low therapeutic index.

Methods

In this study gemcitabine was entrapped within a pegylated liposomal delivery system to improve the drug antitumoral activity, thus exploiting the possibility to reduce doses to be administered in cancer therapy. The cytotoxic effects of free or liposome-entrapped gemcitabine was evaluated against a human thyroid tumour cell line. ARO cells, derived from a thyroid anaplastic carcinoma, were exposed to different concentrations of the drug. Liposomes formulations were made up of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine/cholesterol/1,2-distearoyl-sn-glycero-3-phosphoethanolamine-MPEG (8:3:1 molar ratio). Cell viability was assessed by both trypan bleu dye exclusion assay and fluorimetric analysis of cell DNA content.

Results

A cytotoxic effect of free gemcitabine was present only after 72 h incubation (ARO cell mortality increased of approximately 4 fold over control at 1 μM, 7 fold at 100 μM). When gemcitabine was encapsulated in liposomes, a significant effect was observed by using lower concentrations of the drug (increased cell mortality of 2.4 fold vs. control at 0.3 μM) and earlier exposure time (24 h).

Conclusion

These findings show that, in vitro against human thyroid cancer cells, the gemcitabine incorporation within liposomes enhances the drug cytotoxic effect with respect to free gemcitabine, thus suggesting a more effective drug uptake inside the cells. This may allow the use of new formulations with lower dosages (side effect free) for the treatment of anaplastic human thyroid tumours.
Survey of attitudes, materials and methods employed in endodontic treatment by general dental practitioners in North Jordan
Authors: Al-Omari Wael M
Published: September 2004

Background

General dental practitioners provide the majority of endodontic treatment in Jordan. The aim of this study was to gather information on the methods, materials and attitudes employed in root canal treatment by dentists in North Jordan, in order to evaluate and improve the quality of current practice.

Methods

A questionnaire was posted to all registered general dental practitioners working in private practice in Irbid Governate in North Jordan (n = 181). The questionnaire included information on methods, materials and techniques used in endodontic treatment.

Results

Reply rate was 72% (n = 131). The results demonstrated that only five dentists used rubber dam occasionally and not routinely. The majority used cotton rolls for isolation solely or in combination with a high volume saliva ejector (n = 116). The most widely used irrigants were sodium hypochlorite and hydrogen peroxide, which were used by 32.9% (n = 43) and 33.6% (n = 44) of the respondents, respectively. Forty eight percent of the respondents (n = 61) used the cold lateral condensation technique for canal obturation, 31.3% (n = 41) used single cone, 9.9% (n = 13) used vertical condensation and 12.2% (n = 16) used paste or cement only for the obturation. The majority used zinc oxide eugenol as a sealer (72.5%). All, but one, respondents used hand instruments for canal preparation and the technique of choice was step back (52.7%). More than 50% (n = 70) of the dentists took one radiograph for determining the working length, whilst 22.9% (n = 30) did not take any radiograph at all. Most practitioners performed treatment in three visits for teeth with two or more root canals, and in two visits for teeth with a single root canal.

Conclusions

This study indicates that dentists practicing in North Jordan do not comply with international quality standards and do not use recently introduced techniques. Many clinicians never take a radiograph for determining the working length and never used rubber dam or intra-canal medicaments.
Additional collection devices used in conjunction with the SurePath Liquid-Based Pap Test broom device do not enhance diagnostic utility
Authors: Day Sarah J , O'Shaughnessy Darla L , O'Connor Jason C , Freund Gregory G
Published: September 2004

Background

We have previously shown that use of an EC brush device in combination with the Rovers Cervex-Brush (SurePath broom) offered no significant improvement in EC recovery. Here we determine if use of additional collection devices enhance the diagnostic utility of the SurePath Pap for gynecologic cytology.

Methods

After informed consent, 37 women ages 18–56 receiving their routine cervical examinations were randomized into four experimental groups. Each group was first sampled with the SurePath broom then immediately re-sampled with an additional collection device or devices. Group 1: Rover endocervix brush (n = 8). Group 2: Medscand CytoBrush Plus GT (n = 7). Group 3: Rover spatula + endocervix brush (n = 11). Group 4: Medscand spatula + CytoBrush Plus GT (n = 11).

Results

Examination of SurePath broom-collected cytology yielded the following abnormal diagnoses: atypia (n = 2), LSIL (n = 5) and HSIL (n = 3). Comparison of these diagnoses to those obtained from paired samples using the additional collection devices showed that use of a second and or third device yielded no additional abnormal diagnoses. Importantly, use of additional devices did not improve upon the abnormal cell recovery of the SurePath broom and in 4/10 cases under-predicted or did not detect the SurePath broom-collected lesion as confirmed by cervical biopsy. Finally, in 36/37 cases, the SurePath broom successfully recovered ECs. Use of additional devices, in Group 3, augmented EC recovery to 37/37.

Conclusions

Use of additional collection devices in conjunction with the SurePath broom did not enhance diagnostic utility of the SurePath Pap. A potential but not significant improvement in EC recovery might be seen with the use of three devices.
Feasibility of a patient decision aid regarding disclosure of personal health information: qualitative evaluation of the Health Care Information Directive
Authors: Tracy C Shawn , Dantas Guilherme Coelho , Upshur Ross EG
Published: September 2004

Background

Concerns regarding the privacy of health information are escalating owing both to the growing use of information technology to store and exchange data and to the increasing demand on the part of patients to control the use of their medical records. The objective of this study was to evaluate the Health Care Information Directive (HCID), a recently-developed patient decision aid that aims to delineate the level of health information an individual is willing to share.

Methods

We convened a series of four focus group meetings with several communities in a large Canadian city. A total of 28 men and women participated, representing health care consumer advocates, urban professionals, senior citizens, and immigrants who speak English as a second language. Data were analysed using qualitative methods.

Results

Participants lacked substantial knowledge regarding the fate and uses of personal health information. They expressed mistrust concerning how their information will be used and protected. Several suggestions were made towards customizing the use of data according to specific needs rather than broad and full access to their charts. Furthermore, despite concern regarding the implementation of a tool like the HCID, participants were hopeful that a refined instrument could contribute to the improved regulation of health information.

Conclusion

This study indicated poor knowledge concerning the uses of personal health information, distrust concerning security provisions, and cautious support for a patient decision aid such as the HCID to improve control over health data.
Metabolic response of people with type 2 diabetes to a high protein diet
Authors: Nuttall Frank Q , Gannon Mary C
Published: September 2004

Background

One of the major interests in our laboratory has been to develop a scientific framework for dietary advice for patients with diabetes. Knowledge regarding the metabolic consequences and potential effects on health of protein in people with type 2 diabetes has been a particular interest.

Results

We recently have completed a study in which dietary protein was increased from 15% to 30% of total food energy. The carbohydrate content was decreased from 55% to 40%, i.e. dietary protein replaced part of the carbohydrate. This resulted in a significant decrease in total glycohemoglobin, a decrease in postprandial glucose concentrations and a modest increase in insulin concentration. Renal function was unchanged.

Currently we also are determining the metabolic response to a diet in which the carbohydrate content is further decreased to 20% of total food energy. The %tGHb decrease was even more dramatic than with the 40% carbohydrate diet.

Conclusion

From these data we conclude that increasing the protein content of the diet at the expense of carbohydrate can reduce the 24-hour integrated plasma glucose concentration, at least over a 5-week period of time. The reduction was similar to that of oral agents. Renal function was not affected significantly. Thus, increasing the protein content of the diet with a corresponding decrease in the carbohydrate content potentially is a patient empowering way of reducing the hyperglycemia present with type 2 diabetes mellitus, independent of the use of pharmaceutical agents.
The Na+–H+exchanger-1 induces cytoskeletal changes involving reciprocal RhoA and Rac1 signaling, resulting in motility and invasion in MDA-MB-435 cells
Authors: Paradiso Angelo , Cardone Rosa Angela , Bellizzi Antonia , Bagorda Anna , Guerra Lorenzo , Tommasino Massimo , Casavola Valeria , Reshkin Stephan J
Published: September 2004

Introduction

An increasing body of evidence shows that the tumour microenvironment is essential in driving neoplastic progression. The low serum component of this microenvironment stimulates motility/invasion in human breast cancer cells via activation of the Na+–H+ exchanger (NHE) isoform 1, but the signal transduction systems that underlie this process are still poorly understood. We undertook the present study to elucidate the role and pattern of regulation by the Rho GTPases of this serum deprivation-dependent activation of both NHE1 and subsequent invasive characteristics, such as pseudopodia and invadiopodia protrusion, directed cell motility and penetration of normal tissues.

Methods

The present study was performed in a well characterized human mammary epithelial cell line representing late stage metastatic progression, MDA-MB-435. The activity of RhoA and Rac1 was modified using their dominant negative and constitutively active mutants and the activity of NHE1, cell motility/invasion, F-actin content and cell shape were measured.

Results

We show for the first time that serum deprivation induces NHE1-dependent morphological and cytoskeletal changes in metastatic cells via a reciprocal interaction of RhoA and Rac1, resulting in increased chemotaxis and invasion. Deprivation changed cell shape by reducing the amount of F-actin and inducing the formation of leading edge pseudopodia. Serum deprivation inhibited RhoA activity and stimulated Rac1 activity. Rac1 and RhoA were antagonistic regulators of both basal and stimulated tumour cell NHE1 activity. The regulation of NHE1 activity by RhoA and Rac1 in both conditions was mediated by an alteration in intracellular proton affinity of the exchanger. Interestingly, the role of each of these G-proteins was reversed during serum deprivation; basal NHE1 activity was regulated positively by RhoA and negatively by Rac1, whereas RhoA negatively and Rac1 positively directed the stimulation of NHE1 during serum deprivation. Importantly, the same pattern of RhoA and Rac1 regulation found for NHE1 activity was observed in both basal and serum deprivation dependent increases in motility, invasion and actin cytoskeletal organization.

Conclusion

Our findings suggest that the reported antagonistic roles of RhoA and Rac1 in cell motility/invasion and cytoskeletal organization may be due, in part, to their concerted action on NHE1 activity as a convergence point.
Tsunami Hazards Associated with the Catalina Fault in Southern California
Authors: Legg Mark R. , Borrero Jose C. , Synolakis Costas E.
Published: September 2004

We investigate the tsunami hazard associated with the Catalina Fault offshore of southern California. Realistic faulting parameters are used to match coseismic displacements to existing sea floor topography. Several earthquake scenarios with moment magnitudes ranging between 7.0 and 7.6 are used as initial conditions for tsunami simulations, which predict runup of up to 4 m. Normalizing runup with the maximum uplift identifies areas susceptible to tsunami focusing and amplification. Several harbors and ports in southern California lie in areas where models predict tsunami amplification. Return periods are estimated by dividing the modeled seafloor uplift per event by the observed total uplift of the Santa Catalina Island platform multiplied by the time since the uplift began. The analysis yields return periods between 2,000 to 5,000 years for the Catalina Fault alone, and 200 to 500 years when all offshore faults are considered.
Case Study of a Northridge Welded Steel Moment-Frame Building Having Severed Columns
Authors: Maison Bruce F. , Hale Tom H.
Published: September 2004

The two-story welded steel moment-frame (WSMF) essential services building had columns severed by the 1994 Northridge earthquake. Two of eight columns suffered fracture across both flanges and panel zones in the WSMFs oriented in the north-south direction. Building and connection damage are described; computer models of the building are formulated and used in a damage correlation exercise that aids in damage interpretation; and a calibrated model is used as the basis of special studies. Factors contributing to the severed columns appear to be column-steel low-fracture toughness, panel zone detailing, and panel-zone shear yielding. Using FEMA-351 guidelines, the as-built as well as the Northridge-damaged structure pass the global collapse prevention drift criterion and fail the local collapse prevention drift criterion. The results provide insight regarding the seismic safety of buildings having similar conditions.
Modeling and Response Prediction in Performance-Based Seismic Evaluation: Case Studies of Instrumented Steel Moment-Frame Buildings
Authors: Kunnath Sashi K. , Nghiem Quan , El-Tawil Sherif
Published: September 2004

An evaluation of the four analytical methods recommended in FEMA-356 for the estimation of seismic demands is carried out on two instrumented steel buildings. Prior to conducting the FEMA-356 analyses, computer models of each structural system were calibrated to observed response data. One of the two buildings that experienced no visible damage during Northridge was modeled as a three-dimensional system, while the second building that suffered moderate damage during the Northridge earthquake was further tuned to yield a simplified two-dimensional model so that detailed inelastic evaluations could be performed on the model. Dozens of linear and nonlinear computer analyses under both static and seismic loads were carried out on each building, and typical results representing a summary of the findings are presented in this paper. Results of the evaluations provide insight into both modeling issues and the validity of the four analytical procedures outlined in FEMA-356. It is found that calibrating structural models to observed response is sensitive to mass and stiffness modeling assumptions and indirectly to the intensity of the ground motion that has an effect on the participation of nonstructural components. Linear and nonlinear static procedures do not consistently predict interstory drift estimates, a critical parameter in seismic evaluation and design. The linear static approach was found to be conservative in one case study while the findings from the second case study were less conclusive about the validity of each analytical procedure. This suggests that significant changes are warranted in the proposed FEMA-356 Prestandard if it is to be adopted in future design codes or in seismic evaluation studies of existing buildings.
Use of Satellite SAR Intensity Imagery for Detecting Building Areas Damaged Due to Earthquakes
Authors: Matsuoka Masashi , Yamazaki Fumio
Published: September 2004

Synthetic aperture radar (SAR) is remarkable for its capability to record the backscattering coefficient, the physical value of the earth's surface, regardless of weather condition or sun illumination. Therefore, SAR is a powerful tool that can be utilized to develop a universal method to comprehend damaged areas in disasters such as earthquakes, forest fires, and floods. We performed a feasibility study on backscattering characteristics of damaged areas in the 1995 Hyogoken-Nanbu (Kobe), Japan, earthquake using the pre- and post-event ERS images, revealing that the backscattering coefficient and intensity correlation between the two attained values were significantly lowered in hard-hit areas. The evaluation, however, was performed without speckle noise reduction. We also investigated the effects of speckle noise reduction and pixel-window size in evaluating building damage using the difference in the backscattering coefficient and correlation coefficient of the pre- and post-event ERS images. From the analysis, an optimum window size for the damage evaluation was obtained. It was also found that the accuracy of damage detection is not significantly improved for speckle-reduction filtering of window size larger than 21×21 pixels. We developed an automated method to detect hard-hit areas based on the discriminant analysis, and compared the detected distribution with a damage survey result.
Blind Predictions of the Seismic Response of a Woodframe House: An International Benchmark Study
Authors: Folz Bryan , Filiatrault Andre
Published: September 2004

As part of the CUREE-Caltech Woodframe Project, the international engineering community was invited to blind predict the dynamic characteristics and inelastic seismic response of a two-story woodframe house that had been extensively tested on a shake table. This research study provided a unique opportunity to assess the state of the art of numerical models in predicting the inelastic dynamic response of woodframe structures. Another objective of this study was to foster cooperation between the CUREE-Caltech Woodframe Project and other related research activities being conducted worldwide. Five international teams completed the benchmark exercise and provided blind predictions of the nonlinear time-history response of the shake-table test structure under varying levels of seismic input as well as its pushover response. The participating teams adopted a wide range of numerical models and solution strategies. This paper provides a summary of the activities conducted under the CUREE-Caltech Woodframe Project International Benchmark Study.
Evaluation of a Modified MPA Procedure Assuming Higher Modes as Elastic to Estimate Seismic Demands
Authors: Chopra Anil K. , Goel Rakesh K. , Chintanapakdee Chatpan
Published: September 2004

The modal pushover analysis (MPA) procedure, which includes the contributions of all significant modes of vibration, estimates seismic demands much more accurately than current pushover procedures used in structural engineering practice. Outlined in this paper is a modified MPA (MMPA) procedure wherein the response contributions of higher vibration modes are computed by assuming the building to be linearly elastic, thus reducing the computational effort. After outlining such a modified procedure, its accuracy is evaluated for a variety of frame buildings and ground motion ensembles. Although it is not necessarily more accurate than the MPA procedure, the MMPA procedure is an attractive alternative for practical application because it leads to a larger estimate of seismic demands, improving the accuracy of the MPA results in some cases (relative to nonlinear response history analysis) and increasing their conservatism in others. However, such conservatism is unacceptably large for lightly damped systems, with damping significantly less than 5%. Thus the MMPA procedure is not recommended for such systems.
Losses to Single-Family Housing from Ground Motions in the 1994 Northridge, California, Earthquake
Authors: Wesson Robert L. , Perkins David M. , Leyendecker Edgar V. , Roth Richard J. , Petersen Mark D.
Published: September 2004

The distributions of insured losses to single-family housing following the 1994 Northridge, California, earthquake for 234 ZIP codes can be satisfactorily modeled with gamma distributions. Regressions of the parameters in the gamma distribution on estimates of ground motion, derived from ShakeMap estimates or from interpolated observations, provide a basis for developing curves of conditional probability of loss given a ground motion. Comparison of the resulting estimates of aggregate loss with the actual aggregate loss gives satisfactory agreement for several different ground-motion parameters. Estimates of loss based on a deterministic spatial model of the earthquake ground motion, using standard attenuation relationships and NEHRP soil factors, give satisfactory results for some ground-motion parameters if the input ground motions are increased about one and one-half standard deviations above the median, reflecting the fact that the ground motions for the Northridge earthquake tended to be higher than the median ground motion for other earthquakes with similar magnitude. The results give promise for making estimates of insured losses to a similar building stock under future earthquake loading.
Measuring Improvements in the Disaster Resilience of Communities
Authors: Chang Stephanie E. , Shinozuka Masanobu
Published: September 2004

This paper demonstrates the concept of disaster resilience through the development and application of quantitative measures. As the idea of building disaster-resilient communities gains acceptance, new methods are needed that go beyond estimating monetary losses and that address the complex, multiple dimensions of resilience. These dimensions include technical, organizational, social, and economic facets. This paper first proposes resilience measures that relate expected losses in future disasters to a community's seismic performance objectives. It then demonstrates these measures in a case study of the Memphis, Tennessee, water delivery system. An existing earthquake loss estimation model provides a starting point for quantifying resilience. The analysis compares two seismic retrofit strategies and finds that only one improves community resilience over the status quo. However, it does not raise resilience to an adequate degree. The exercise demonstrates that the resilience framework can be valuable for guiding mitigation and preparedness efforts. However, to fully implement the concept, new research on resilience is needed that goes beyond loss estimation modeling.
Seismic Evaluation of Low-Rise Reinforced Masonry Buildings with Flexible Diaphragms: I. Seismic and Quasi-Static Testing
Authors: Cohen Gregory L. , Klingner Richard E. , Hayes John R. , Sweeney Steven C.
Published: September 2004

This and a companion paper compare the results from shaking-table testing, quasi-static testing, and analytical predictions, to provide a coherent description of the seismic response of low-rise reinforced masonry buildings with flexible roof diaphragms. Two half-scale, low-rise reinforced masonry buildings with flexible roof diaphragms are subjected to earthquake ground motions on the Tri-axial Earthquake and Shock Simulator at the United States Army Construction Engineering Research Laboratory, Engineer Research and Development Center. Following the shaking-table tests, diaphragms and top four courses of attached masonry walls are salvaged from the half-scale structures and tested quasi-statically in their own plane. In contrast to what is usually assumed in design, the half-scale specimens do not behave as systems with a single degree of freedom associated with the in-plane response of the shear walls, but rather a system with a dominant degree of freedom associated with the in-plane response of the roof diaphragm. A new index describing the potential for diaphragm damage is introduced, the diaphragm drift ratio. A companion paper, Part II: Analytical Modeling, presents analytical work intended to corroborate and extend results from experimental testing.
Seismic Evaluation of Low-Rise Reinforced Masonry Buildings with Flexible Diaphragms: II. Analytical Modeling
Authors: Cohen Gregory L. , Klingner Richard E. , Hayes John R. , Sweeney Steven C.
Published: September 2004

This and a companion paper compare the results from shaking-table testing, quasi-static testing, and analytical predictions to provide a coherent description of the seismic response of low-rise reinforced masonry buildings with flexible roof diaphragms. This paper presents the development, implementation, and results of coordinated analytical modeling intended to corroborate and extend the results of experimental work discussed in a companion paper, Part I: Seismic and Quasi-Static Testing, and more important, examine the efficacy and accuracy of different analytical modeling approaches. Specifically, linear elastic finite-element models, simplified two-degree-of-freedom models, and nonlinear lumped-parameter models are created and all agree well with measured responses. Based on these, a simple design tool for the analysis of low-rise reinforced masonry buildings with flexible diaphragms is developed and verified.
Seismological Aspects of the 2002 Denali Fault, Alaska, Earthquake
Authors: Hansen Roger A. , Ratchkovski Natalia A.
Published: September 2004

The M7.9 Denali fault earthquake occurred on 3 November 2002 with an epicenter located 135 km south of Fairbanks and 283 km north of Anchorage. This epicenter is 22–25 km east of the M6.7 Nenana Mountain earthquake that occurred eleven days earlier, October 23, awakening some inhabitants of central Alaska at about 3:30 that morning. Like most earthquakes of its size, the M7.9 earthquake was a complex event. The rupture began with vertical slip along a 40-km segment of the previously unrecognized Susitna Glacier thrust fault, which is connected to the Denali fault. The rupture continued with right-lateral horizontal slip along the main trace of the Denali fault. It eventually split off the Denali fault onto the more southeast-trending Totschunda fault. The total rupture length was 330–340 kilometers, with at least three areas of high slip, or high energy release.
Strong-Motion Records of the 2002 Denali Fault, Alaska, Earthquake
Authors: Martirosyan Artak , Hansen Roger , Ratchkovski Natalia
Published: September 2004

The MW 7.9 Denali Fault earthquake on 3 November 2002 ruptured a 340-km section along the Susitna Glacier, Denali, and Totschunda faults in central Alaska. The earthquake was digitally recorded at more than 55 strong-motion sites throughout the state at distances up to 280 km from the fault rupture. The site closest to the fault, Trans-Alaska Pipeline Pump Station 10, is located about 3 km north of the surface rupture, where the observed maximum horizontal peak ground acceleration was about 0.35 g. The peak horizontal accelerations observed at the sites closest to the fault rupture were considerably smaller than those yielded by the ground-motion prediction equations. Although the earthquake provided a valuable set of strong-motion data, an important opportunity was missed to capture near-field recordings from such a major strike-slip event. A concerted national effort is needed to prioritize the instrumentation of faults that are likely locations of future great earthquakes.
Near-Field Ground Motion of the 2002 Denali Fault, Alaska, Earthquake Recorded at Pump Station 10
Authors: Ellsworth W. L. , Celebi M. , Evans J. R. , Jensen E. G. , Kayen R. , Metz M. C. , Nyman D. J. , Roddick J. W. , Spudich P. , Stephens C. D.
Published: September 2004

A free-field recording of the Denali fault earthquake was obtained by the Alyeska Pipeline Service Company 3 km from the surface rupture of the Denali fault. The instrument, part of the monitoring and control system for the trans-Alaska pipeline, was located at Pump Station 10, approximately 85 km east of the epicenter. After correction for the measured instrument response, we recover a seismogram that includes a permanent displacement of 3.0 m. The recorded ground motion has relatively low peak acceleration (0.36 g) and very high peak velocity (180 cm/s). Nonlinear soil response may have reduced the peak acceleration to this 0.36 g value. Accelerations in excess of 0.1 g lasted for 10 s, with the most intense motion occurring during a 1.5-s interval when the rupture passed the site. The low acceleration and high velocity observed near the fault in this earthquake agree with observations from other recent large-magnitude earthquakes.
Landslides Triggered by the 2002 Denali Fault, Alaska, Earthquake and the Inferred Nature of the Strong Shaking
Authors: Jibson Randall W. , Harp Edwin L. , Schulz William , Keefer David K.
Published: September 2004

The 2002 M7.9 Denali fault, Alaska, earthquake triggered thousands of landslides, primarily rock falls and rock slides, that ranged in volume from rock falls of a few cubic meters to rock avalanches having volumes as great as 15×106 m3. The pattern of landsliding was unusual; the number of slides was less than expected for an earthquake of this magnitude, and the landslides were concentrated in a narrow zone 30-km wide that straddled the fault rupture over its entire 300-km length. The large rock avalanches all clustered along the western third of the rupture zone where acceleration levels and ground-shaking frequencies are thought to have been the highest. Inferences about near-field strong shaking characteristics drawn from the interpretation of the landslide distribution are consistent with results of recent inversion modeling that indicate high-frequency energy generation was greatest in the western part of the fault rupture zone and decreased markedly to the east.
Geotechnical Reconnaissance of the 2002 Denali Fault, Alaska, Earthquake
Authors: Kayen Robert , Thompson Eric , Minasian Diane , Moss Robb E. S. , Collins Brian D. , Sitar Nicholas , Dreger Douglas , Carver Gary
Published: September 2004

The 2002 M7.9 Denali fault earthquake resulted in 340 km of ruptures along three separate faults, causing widespread liquefaction in the fluvial deposits of the alpine valleys of the Alaska Range and eastern lowlands of the Tanana River. Areas affected by liquefaction are largely confined to Holocene alluvial deposits, man-made embankments, and backfills. Liquefaction damage, sparse surrounding the fault rupture in the western region, was abundant and severe on the eastern rivers: the Robertson, Slana, Tok, Chisana, Nabesna and Tanana Rivers. Synthetic seismograms from a kinematic source model suggest that the eastern region of the rupture zone had elevated strong-motion levels due to rupture directivity, supporting observations of elevated geotechnical damage. We use augered soil samples and shear-wave velocity profiles made with a portable apparatus for the spectral analysis of surface waves (SASW) to characterize soil properties and stiffness at liquefaction sites and three trans-Alaska pipeline pump station accelerometer locations.
Response of a 14-Story Anchorage, Alaska, Building in 2002 to Two Close Earthquakes and Two Distant Denali Fault Earthquakes
Authors: Celebi Mehmet
Published: September 2004

The recorded responses of an Anchorage, Alaska, building during four significant earthquakes that occurred in 2002 are studied. Two earthquakes, including the 3 November 2002 M7.9 Denali fault earthquake, with epicenters approximately 275 km from the building, generated long trains of long-period (>1 s) surface waves. The other two smaller earthquakes occurred at subcrustal depths practically beneath Anchorage and produced higher frequency motions. These two pairs of earthquakes have different impacts on the response of the building. Higher modes are more pronounced in the building response during the smaller nearby events. The building responses indicate that the close-coupling of translational and torsional modes causes a significant beating effect. It is also possible that there is some resonance occurring due to the site frequency being close to the structural frequency. Identification of dynamic characteristics and behavior of buildings can provide important lessons for future earthquake-resistant designs and retrofit of existing buildings.
Quantitative signature for architectural organization of regulatory factors using intranuclear informatics
Authors: Young Daniel W. , Zaidi Sayyed K. , Furcinitti Paul S. , Javed Amjad , van Wijnen Andre J. , Stein Janet L. , Lian Jane B. , Stein Gary S.
Published: September 2004

Regulatory machinery for replication and gene expression is punctately organized in supramolecular complexes that are compartmentalized in nuclear microenvironments. Quantitative approaches are required to understand the assembly of regulatory machinery within the context of nuclear architecture and to provide a mechanistic link with biological control. We have developed `intranuclear informatics' to quantify functionally relevant parameters of spatially organized nuclear domains. Using this informatics strategy we have characterized post-mitotic reestablishment of focal subnuclear organization of Runx (AML/Cbfa) transcription factors in progeny cells. By analyzing point mutations that abrogate fidelity of Runx intranuclear targeting, we establish molecular determinants for the spatial order of Runx domains. Our novel approach provides evidence that architectural organization of Runx factors may be fundamental to their tissue-specific regulatory function.
Novel nuclear defects in KLP61F-deficient mutants inDrosophilaare partially suppressed by loss of Ncd function
Authors: Wilson Patricia G. , Simmons Robert , Shigali Sheena
Published: September 2004

KLP61F in Drosophila and other BimC kinesins are essential for spindle bipolarity across species; loss of BimC function generates high frequencies of monopolar spindles. Concomitant loss of Kar3 kinesin function increases the frequency of bipolar spindles although the underlying mechanism is not known. Recent studies raise the question of whether BimC kinesins interact with a non-microtubule spindle matrix rather than spindle microtubules. Here we present cytological evidence that loss of KLP61F function generates novel defects during M-phase in the organization and integrity of the nuclear lamina, an integral component of the nuclear matrix. Larval neuroblasts and spermatocytes of klp61F mutants showed deep involutions in the nuclear lamina extending toward the centrally located centrosomes. Repositioning of centrosomes to form monopolar spindles probably does not cause invaginations as similar invaginations formed in spermatocytes lacking centrosomes entirely. Immunofluorescence microscopy indicated that non-claret disjunctional (Ncd) is a component of the nuclear matrix in somatic cells and spermatocytes. Loss of Ncd function increases the frequency of bipolar spindles in klp61F mutants. Nuclear defects were incompletely suppressed; micronuclei formed near telophase at the poles of bipolar spindle in klp61F ncd spermatocytes. Our results are consistent with a model in which KLP61F prevents Ncd-mediated collapse of a nonmicrotubule matrix derived from the interphase nucleus.
After double-strand break induction by UV-A, homologous recombination and nonhomologous end joining cooperate at the same DSB if both systems are available
Authors: Rapp Alexander , Greulich Karl Otto
Published: September 2004

After induction of DNA double-strand breaks (DSB) two repair systems, the error-prone `nonhomologous end joining' (NHEJ) and the more accurate `homologous recombination repair' (HRR) can compete for the same individual DSB site. In the human keratinocyte cell line, HaCaT, we have tested the spatial co-localisation and the temporal sequence of events. We used UV-A (365 nm) as a damaging agent, which can be applied in clearly defined doses and can lead to rare DSBs via propagation of clustered single-strand breaks (SSBs). DNA fragmentation and repair was measured by the Comet assay and persisting DSBs were quantified by the micronucleus assay. Direct DSB detection was performed by immunohistochemical labelling of γ-H2AX, a phosphorylated histone that is assumed to form one foci per DSB. Intra- and inter-pathway interactions were quantified by co-localisation, FRET imaging and by co-immunoprecipitation (Co-IP) of XRCC4, DNA-PK and Ku70 as representatives of NHEJ, Rad51 and Rad52 for HRR and γ-H2AX, Mre11 and Rad50 as representatives of both pathways. In G2 cells, where both systems are available, the temporal sequence after irradiation is: (1) γ-H2AX (2) Mre11 (3) DNA-PK Rad51 (4) XRCC4. That is, the first two proteins involved in both pathways `label' the damaged site and initiate repair, followed by the NHEJ, which is temporally overlapping with HRR activity. Taking all these observations together we suggest that a cell tries to repair DSBs with a combination of both HRR and NHEJ, if available.
Nvj1p is the outer-nuclear-membrane receptor for oxysterol-binding protein homolog Osh1p inSaccharomyces cerevisiae
Authors: Kvam Erik , Goldfarb David S.
Published: September 2004

OSH1 belongs to a seven-member gene family in yeast that is related to mammalian oxysterol-binding protein (OSBP). Here, we investigate the targeting of Osh1p to nucleus-vacuole (NV) junctions in Saccharomyces cerevisiae. NV junctions are interorganelle interfaces mediated by Nvj1p in the nuclear envelope and Vac8p on the vacuole membrane. Together, Nvj1p and Vac8p form Velcro-like patches through which teardrop-like portions of the nucleus are pinched off into the vacuolar lumen and degraded by a process termed piecemeal microautophagy of the nucleus (PMN). Osh1p is targeted to NV junctions proportional to NVJ1 expression through a physical association with Nvj1p. NV junctions per se are not required for this targeting because Osh1p colocalizes with Nvj1p in the absence of Vac8p. NV-junction-associated Osh1p is also a substrate for PMN degradation. Although OSH1 is not required for NV-junction formation or PMN, PMN is defective in cells lacking the yeast OSBP family (Osh1p to Osh7p). By contrast, the vesicular targeting of aminopeptidase I to the vacuole by macroautophagy is not dependent on the Osh protein family. We conclude the formation of nuclear PMN vesicles requires the overlapping activities of Osh1p and other Osh family members.
Hsp70 dynamics in vivo: effect of heat shock and protein aggregation
Authors: Zeng Xian-Chun , Bhasin Samir , Wu Xufeng , Lee Joeng-Goo , Maffi Shivani , Nichols Christopher J. , Lee Kyung Jin , Taylor J. Paul , Greene Lois E. , Eisenberg Evan
Published: September 2004

The molecular chaperone Hsp70 interacts with misfolded proteins and also accumulates in the nucleus during heat shock. Using GFP-Hsp70 and fluorescence recovery after photobleaching, we show that Hsp70 accumulates in the nucleus during heat shock not only because its inflow rate increases but also because of a marked decrease in its outflow rate. Dynamic imaging also shows that GFP-Hsp70 has greatly reduced mobility when it interacts with organelles such as nucleoli in heat-shocked cells or the large inclusions formed from fragments of mutant huntingtin protein. In heat-shocked cells, nucleoplasmic Hsp70 has reduced mobility relative to the cytoplasm, whereas the ATPase-deficient mutant of Hsp70, Hsp70(K71E), is almost completely immobilized both in the nucleoplasm and the cytoplasm. Moreover, the Hsp70 mutant shows reduced mobility in the presence of diffusive huntingtin fragments with expanded polyglutamine repeats. This provides strong evidence that Hsp70 interacts not only with organelles but also with diffusive proteins in the nucleoplasm and cytoplasm during heat shock as well as with diffusive huntingtin fragments.
Regulation of spontaneous meiosis resumption in mouse oocytes by various conventional PKC isozymes depends on cellular compartmentalization
Authors: Avazeri Nathalie , Courtot Anne-Marie , Lefevre Brigitte
Published: September 2004

In this study, we investigated the spatio-temporal distribution of conventional protein kinases C (cPKC) isoforms PKC-α, PKC-βI, PKC-βII and PKC-γ in mouse oocytes. The cPKCs were present in the cytoplasm at the start of the process and migrated to the nucleus (or germinal vesicle) before germinal vesicle breakdown, except for PKC-γ which remained cytoplasmic. In both compartments, the fully phosphorylated form corresponding to the `mature' enzyme was revealed for PKC-α, PKC-βI and PKC-βII. Microinjection of specific antibodies against each isozyme in one or the other cell compartment at different times of the meiotic process, permitted us to observe the following: (1) When located in the cytoplasm at the beginning of the process, PKC-α is not implicated in germinal vesicle breakdown, PKC-βI and PKC-γ are involved in maintaining the meiotic arrest, and PKC-βII plays a role in meiosis reinitiation. Furthermore, just before germinal vesicle breakdown, these cytoplasmic cPKCs were no longer implicated. (2) When located in the germinal vesicle, PKC-α, PKC-βI and PKC-βII are involved in meiosis reinitiation. Our data highlight not only the importance of the nuclear pathways in the cell cycle progression, but also their independence of the cytoplasmic ones. Further investigations are however necessary to discover the molecular targets of these cPKCs to better understand the links with the cell cycle progression.
Apical localization of actin patches and vacuolar dynamics in Ashbya gossypii depend on the WASP homolog Wal1p
Authors: Walther Andrea , Wendland Jürgen
Published: September 2004

Analysis of the Ashbya gossypii Wiskott-Aldrich syndrome-like gene AgWAL1 indicates that it is required for the maintenance of polarized hyphal growth. Growth and organelle dynamics of the wild type and of wal1 and other mutant strains were monitored by in vivo (fluorescence) time-lapse microscopy. Loss of WAL1 led to slow growth and defects in polarized growth that produced swellings in subapical regions, whereas formation of hyphal tips and dichotomous tip branching occurred as in the wild-type. Few actin cables in Agwal1 cells were found to insert into the hyphal tip, but specific clustering of cortical actin patches was observed in subapical regions of hyphal tips instead of at the hyphal apex. Distribution and movement of vacuoles was observed in vivo using FM4-64. In the wild type and in the slowly growing mutant strains bem2 and cla4, which lack a Rho-GTPase-activating protein and a PAK kinase, respectively, early endosomes appeared in the hyphal tip, whereas very few early endosomes and small vacuoles were found in the wal1 mutant hyphal tips, thus linking the cortical patch defect of wal1 hyphae with the distribution of endosomes. Vivid movement of vacuoles seen in the wild type and in the bem2 mutant in subapical regions was largely reduced in the wal1 and cla4 mutants. The tubular structure of mitochondria (as visualized by DIOC6 in vivo) was similar in the wild type and the wal1 mutant, although wal1 mitochondria appeared to be larger. Interestingly, mitochondria were found to insert into the hyphal tips in both strains. Our results indicate a function for Wal1p in filamentous fungi in coordinating actin patch distribution with polarized hyphal tip growth.
Determination of peak vertical ground reaction force from duty factor in the horse (Equus caballus)
Authors: Witte T. H. , Knill K. , Wilson A. M.
Published: September 2004

Measurement of peak vertical ground reaction force (GRFz) from multiple limbs simultaneously during high-speed, over-ground locomotion would enhance our understanding of the locomotor mechanics of cursorial animals. Here, we evaluate the accuracy of predicting peak GRFz from duty factor (the proportion of the stride for which the limb is in contact with the ground). Foot-mounted uniaxial accelerometers, combined with UHF FM telemetry, are shown to be practical and accurate for the field measurement of stride timing variables,including duty factor. Direct comparison with the force plate produces a mean error of 2.3 ms and 3.5 ms for the timing of foot on and foot off,respectively, across all gaits. Predictions of peak GRFz from duty factor show mean errors (with positive values indicating an overestimate) of 0.8±0.04 N kg–1 (13%; N=42; mean ± s.e.m.) at walk, –0.3±0.06 N kg–1 (3%; N=75) at trot, –2.3±0.27 N kg–1 (16%; N=18) for the non-lead limb at canter and+2.1±0.7 N kg–1 (19%; N=9) for the lead limb at canter. The substantial over- and underestimate seen at canter, in the lead and non-lead limbs, respectively, is attributed to the different functions performed by the two limbs in the asymmetrical gaits. The difference in load experienced by the lead and non-lead limbs decreased with increasing speed.
Identification of the most abundant secreted proteins from the salivary glands of the sand flyLutzomyia longipalpis, vector ofLeishmania chagasi
Authors: Valenzuela Jesus G. , Garfield Mark , Rowton Edgar D. , Pham Van M.
Published: September 2004

Using massive cDNA sequencing, proteomics and customized computational biology approaches, we have isolated and identified the most abundant secreted proteins from the salivary glands of the sand fly Lutzomyia longipalpis. Out of 550 randomly isolated clones from a full-length salivary gland cDNA library, we found 143 clusters or families of related proteins. Out of these 143 families, 35 were predicted to be secreted proteins. We confirmed, by Edman degradation of Lu. longipalpissalivary proteins, the presence of 17 proteins from this group. Full-length sequence for 35 cDNA messages for secretory proteins is reported, including an RGD-containing peptide, three members of the yellow-related family of proteins, maxadilan, a PpSP15-related protein, six members of a family of putative anticoagulants, an antigen 5-related protein, a D7-related protein, a cDNA belonging to the Cimex apyrase family of proteins, a protein homologous to a silk protein with amino acid repeats resembling extracellular matrix proteins, a 5′-nucleotidase, a peptidase, a palmitoyl-hydrolase, an endonuclease, nine novel peptides and four different groups of proteins with no homologies to any protein deposited in accessible databases. Sixteen of these proteins appear to be unique to sand flies. With this approach, we have tripled the number of isolated secretory proteins from this sand fly. Because of the relationship between the vertebrate host immune response to salivary proteins and protection to parasite infection, these proteins are promising markers for vector exposure and attractive targets for vaccine development to control Leishmania chagasi infection.