bluuebunny/crossref_metadata_2025 huggingface dataset:
Traditional healthy mediterranean diet: estrogenic activity of plants used as food and flavoring agents
Authors: Agradi Elisabetta , Vegeto Elisabetta , Sozzi Andrea , Fico Gelsomina , Regondi Simona , Tomè Franca
Published: June 2006

The Italian‐style Mediterranean diet has been defined as healthy by epidemiologists and nutritionists. Besides being low fat, the Mediterranean diet is rich in biologically active minor compounds. Among these, phytoestrogens seem to have an impact on the prevention of chronic degenerative disease. It is important to understand how this occurs. The in vitro estrogenic activity of crude extracts from typical Mediterranean foods was tested using a yeast estrogen screen (YES), containing human estrogen receptor. Species belonging to Leguminosae, Apiaceae, Graminaceae, Iridaceae, Chenopodiaceae, Cruciferae and Solanaceae showed the greatest number of positive responses. These species include some foods which are traditionally widely consumed, such as beans and other legumes, tomatoes, cabbage, carrots and some cereals. The highest activity was found in the more polar extracts (aqueous, methanol and chloroform: methanol) indicating that polar compounds are mainly responsible for the estrogenic activity. This is also supported by the traditional cooking practices.

According to data from in vitro tests, the estrogenic activity is present in numerous plants which are commonly used as food in the Mediterranean diet. Vegetable foods rich in phytoestrogens, as in the Mediterranean tradition, may contribute to the maintenance of health status. Copyright © 2006 John Wiley & Sons, Ltd.
Modelling a modified atmosphere packaging system for fresh scallops (Argopecten purpuratus)
Authors: Simpson R. , Carevic E. , Rojas S.
Published: June 2006

Seafood is a highly perishable food, which has a relative short shelf‐life. Modified atmosphere packaging (MAP) is a system that offers a way of extending the shelf‐life of seafood products, maintaining quality and inhibiting bacterial growth. The objective of this research was to study and determine the optimal conditions for packaging scallops in a modified atmosphere system, which includes CO2/O2/N2 mixture, headspace:food ratio and storage temperature, utilizing an integrated mathematical model for MAP systems with its respective experimental validation. For validation purposes, two experiments were conducted, using gas mixtures of: (a) 45% CO2/10% O2/45% N2; and (b) 60% CO2/10% O2/30% N2. In addition, two experiments, at 6°C and 20°C, were conducted to obtain the shelf‐life model, utilizing the following gas mixtures: 30% CO2/10% O2/60% N2; 45% CO2/10% O2/45% N2; 60% CO2/10% O2/30% N2; and 75% CO2/10% O2/15% N2. Gas mixtures with CO2 concentrations between 30% and 70% and different headspace:food ratios were tested during simulations. The optimal conditions for scallop storage were a 60% CO2/10% O2/30% N2 gas mixture and a headspace:food ratio of 2:1. With these conditions, a simulated shelf‐life of 21 days was obtained. Optimal conditions consider maximum shelf‐life, an adequate film collapse criterion, and time to reach the pseudo‐equilibrium condition. The predictive mathematical model, coupled with experimental studies for specific products, can be efficiently utilized to evaluate packaging alternatives (size, material and selected thickness) for different temperatures and initial gas concentration scenarios of MAP products. Copyright © 2006 John Wiley & Sons, Ltd.
Software developer motivation in a high maturity company: a case study
Authors: Baddoo Nathan , Hall Tracy , Jagielska Dorota
Published: June 2006

In this article, we discuss the impact of software developer motivation on projects. Motivation has been reported to be an important determinant of productivity and quality of work in many industries. In this article, we explore specifically how motivation impacts on development work in software engineering. We describe work previously done to suggest that software developers may have a different profile of motivators to other professionals. We present data collected from nine developers working in a software organisation that has been assessed at CMM level 5. We find that the developers working in this high maturity development environment are highly motivated. We also report relationships between motivation and progress in development work and describe the impact of motivating factors on specific aspects of software development. Our main conclusion is that good software developers are proactive, flexible and adaptable, prepared to share knowledge with team and follow good practice, for example, documenting work. Also, and in particular reference to this high maturity company, good software developers are able to resolve complex problems, innovative and eager to try new technology. The biggest motivators to such performance in a high maturity organisation are pay and benefits, recognition and opportunities for achievement. These are closely followed by technically challenging work, job security and senior management support. Cost, time, product quality — in terms of reliability — and user satisfaction are all moderately good indicators of project success. User satisfaction, however, is the best indicator of all four as its importance assumes a temporal significance as a project progresses. Finally, we found that technical competency, interpersonal skills and adherence to good practices impact favourably on software project success. Copyright © 2006 John Wiley & Sons, Ltd.
Software process improvement in Europe: potential of the new V‐modell XT and research issues
Authors: Biffl Stefan , Winkler Dietmar , Höhn Reinhard , Wetzel Herbert
Published: June 2006

The goal of European industrial practice to support high‐value software production in diversified domains has led to the development of a huge number of process model variants. However, these diverse models are hard to compare, which hinders efficient collaboration and software process improvement on a European level. Process managers see a growing need for approaches that support stakeholder collaboration, systematic process mapping, and transformation of processes to improve their leverage in software process improvement. In this article we present the V‐Modell XT (VM XT), a flexible software process model approach that has recently been announced as the standard for public‐sector IT projects in Germany, as promising opportunity to help provide a unifying European software process model ‘umbrella’. On the basis of strengths of the VM XT, we suggest research directions for advanced support of software projects: (i) effective business value translation to engineering solutions that strengthens stakeholder collaboration, (ii) process mapping that enables collaboration in projects that have to reconcile several process models, and (iii) process ‘product lines’ to capture the variability of software processes on domain and company levels and thus systematically help investigate best‐practice approaches to software construction. We discuss these concepts, the contribution of the VM XT, and conclude with next steps for research and validation. Copyright © 2006 John Wiley & Sons, Ltd.
A proposed way for European software industries to achieve growth within the global marketplace
Authors: McCaffery Fergal , Šmite Darja , Wilkie F. G. , McFall D.
Published: June 2006

Global market expansion forces the competition in the field of software development to grow extremely fast. Accordingly, countries that base their brand in the field of information technologies are looking forward to quality and productivity improvement along with price reduction. One of the major trends in the global market is outsourcing, which is considered to be an opportunity to achieve best knowledge, extra resources and assurance of quality development, speed time to market, and cut costs. The role of emerging nations in this context increases every day, pushing out the old players. This article will therefore suggest how software development should change within the Northern Ireland (NI) software industry and adopt a global software development model in order to continue as a major player within the global software development industry. Copyright © 2006 John Wiley & Sons, Ltd.
From process improvement to learning organisations
Authors: Messnarz Richard , O'Suilleabhain Gearoid , Coughlan Ray
Published: June 2006

This article outlines a case study in which process improvement has been combined with innovation management strategies. This approach is a key success factor in the industry because process improvement without regard to product innovation would in the long term only stabilise the productions in existing cash cows, but would not unleash any new product ideas or concepts. However, new product concepts are necessary to win a competitive advantage in the market.

Here, a case study based on ISO 15504 concerning process improvements is discussed. Concerning innovation skills and processes, the case studies discussed are based on the results of three former projects as follows: (a) CREDIT (MM 1032, 1998–2001), developing a multi‐user Intranet/Internet‐based assessment platform for skills and process assessments, (b) ORGANIC (Leonardo da Vinci, 2003–2006), developing a training program for required skills in innovation management, and (c) SOQRATES (originally Bavarian state funded in 2003 and later funded by a group of leading firms in central Europe), comprising task forces shared across companies to exchange process improvement knowledge and jointly collaborate on synergies and improvements. Copyright © 2006 John Wiley & Sons, Ltd.
Release planning process improvement — an industrial case study
Authors: Momoh Joseph , Ruhe Günther
Published: June 2006

Planning of software releases is accomplished by the assignment of requirements to the releases, where effort, finance, and risk constraints are considered in order to determine strategic release plans. Planning and re‐planning of releases has an impact on time‐to‐market, customer satisfaction, and stability of the development process. This article presents an industrial case study of the release planning process improvement as performed at Trema Laboratories, Inc. The baseline situation is compared against the improvement gained from the introduction of a more systematic process defined by a decision support tool called ReleasePlanner, and an accompanying methodology. The new process was designed and implemented as part of a trial project performed at Trema. The article describes the main findings of this trial. The study shows that the process improvement introduced has added significant value to the overall business. Copyright © 2006 John Wiley & Sons, Ltd.
Software outsourcing quality achieved by global virtual collaboration
Authors: Siakas Kerstin V. , Balstrup Bo
Published: June 2006

In today's rapidly changing and highly competitive global environment, offshore outsourcing (contracting of a portion or all of the software development function to software engineers outside the home country) teams working across national borders and virtual organisations have become a fact. The globalisation of the software market has also changed the contextual boundaries of information systems (IS) research and practices to include the wider societal context. Management experiences difficulties when applying traditional management approaches, because of the increased complexity of global organisations and their dependency on people with different underlying norms, values and beliefs. Researchers call for caution in managing global workers. They argue that behavioural traits of diverse work groups can contribute to dysfunctional organisations. Cultural sensitivity has become a core issue.

This article discusses the implications of globalisation in software development and seeks to make more explicit the human dynamics that have a bearing on the success of outsourcing and virtual collaboration. Two models, namely, the e‐Sourcing Capability Model for Service Providers (eSCM‐SP) and the Software Quality Management—Cultural and Organisational Diversity Evaluation (SQM‐CODE) Model, are proposed to bring added value for service purchasers in their search for, selection of and collaboration with service providers.

The eSCM‐SP, a capability maturity assessment model related to IT‐enabled sourcing, is briefly discussed and the SQM‐CODE model, a tool for assessing the fit between organisational and national culture, is presented, and its importance for identifying cultural factors and taking appropriate action in order to achieve a cultural fit between the service provider and the contractor in outsourcing business partnerships is revealed. Copyright © 2006 John Wiley & Sons, Ltd.
Ductus venosus shunting in growth‐restricted fetuses and the effect of umbilical circulatory compromise
Authors: Kiserud T. , Kessler J. , Ebbing C. , Rasmussen S.
Published: June 2006

Objective

To determine the degree of ductus venosus (DV) shunting in fetuses with intrauterine growth restriction (IUGR) and the effect of various degrees of umbilical circulatory compromise.

Methods

This was a cross‐sectional observational study. Sixty‐four fetuses with IUGR (estimated weight ≤ 2.5th percentile) underwent ultrasound examination. The diameter, velocity, and blood flow were determined in the DV and intra‐abdominal umbilical vein (UV), and the fraction of shunting and DV : UV diameter ratios were calculated. Placental compromise was classified according to either normal umbilical artery (UA) pulsatility index (PI), UA‐PI > 97.5th percentile, or absent or reversed end‐diastolic flow velocity (A/REDV). Regression analysis was used to construct mean values, and SD scores were used to determine differences compared with a reference population (n = 212) after ln‐ or power‐transformation.

Results

In the 64 growth‐restricted fetuses, the average DV shunting was 39% compared with 25% in the reference group (overall P < 0.0001). The corresponding values in the subgroups with normal UA‐PI, UA‐PI > 97.5th percentile, and A/REDV were 31%, 35%, and 57%, respectively. Fetuses with IUGR and normal UA‐PI (SD score: mean, 0.48; 95% CI, 0.04–0.92) did not shunt significantly more than did the reference fetuses (SD score: mean, 0.0; 95% CI, − 0.15 to 0.15), but those with UA‐PI > 97.5th percentile (SD score: mean, 0.85; 95% CI, 0.41–1.29), and particularly those with A/REDV (SD score: mean, 1.56; 95% CI, 1.0–2.12) did shunt significantly more. With more DV shunting, these fetuses distributed correspondingly less umbilical blood to the liver, one of the mechanisms being a lower perfusion pressure as reflected in the lower DV blood velocity (P < 0.0001).

Conclusions

DV shunting is higher and the umbilical blood flow to the liver is less in fetuses with IUGR, particularly in those with the most severe umbilical hemodynamic compromise. Copyright © 2006 ISUOG. Published by John Wiley & Sons, Ltd.
Building Bridges Across Differences to Meet Social Action Goals: Being and Creating Allies Among People of Color
Authors: Suyemoto Karen L. , Fox Tree Claudia A.
Published: June 2006

Although challenges of anti‐racist work are most commonly framed in relation to White people and People of Color, there are significant challenges involved in creating allies across minority racial groups. This article describes our experiences within a community organization aimed at training anti‐racist culturally sensitive K‐12 educators. As Asian American and Native American facilitators within a group of facilitators of color who were predominantly Black, we describe our experiences of relative marginalization and our (mostly failed) attempts to create change within the organization to be more inclusive of the perspectives, experiences, and needs of non‐Black people/students of color. We contextualize these experienced conflicts in relation to race hierarchies, the “divide and conquer strategy” and the maintenance of White privilege. We offer reflections for how racial minorities engaged in anti‐racist education could be better allies and how organizations might better foster environments that contribute to the creation of these alliances.
Item Response Theory with Estimation of the Latent Population Distribution Using Spline-Based Densities
Authors: Woods Carol M. , Thissen David
Published: June 2006

The purpose of this paper is to introduce a new method for fitting item response theory models with the latent population distribution estimated from the data using splines. A spline-based density estimation system provides a flexible alternative to existing procedures that use a normal distribution, or a different functional form, for the population distribution. A simulation study shows that the new procedure is feasible in practice, and that when the latent distribution is not well approximated as normal, two-parameter logistic (2PL) item parameter estimates and expected a posteriori scores (EAPs) can be improved over what they would be with the normal model. An example with real data compares the new method and the extant empirical histogram approach.
A Repetitive Branch-and-Bound Procedure for Minimum Within-Cluster Sums of Squares Partitioning
Authors: Brusco Michael J.
Published: June 2006

Minimization of the within-cluster sums of squares (WCSS) is one of the most important optimization criteria in cluster analysis. Although cluster analysis modules in commercial software packages typically use heuristic methods for this criterion, optimal approaches can be computationally feasible for problems of modest size. This paper presents a new branch-and-bound algorithm for minimizing WCSS. Algorithmic enhancements include an effective reordering of objects and a repetitive solution approach that precludes the need for splitting the data set, while maintaining strong bounds throughout the solution process. The new algorithm provided optimal solutions for problems with up to 240 objects and eight well-separated clusters. Poorly separated problems with no inherent cluster structure were optimally solved for up to 60 objects and six clusters. The repetitive branch-and-bound algorithm was also successfully applied to three empirical data sets from the classification literature.
Taxicab Correspondence Analysis
Authors: Choulakian V.
Published: June 2006

Taxicab correspondence analysis is based on the taxicab singular value decomposition of a contingency table, and it shares some similar properties with correspondence analysis. It is more robust than the ordinary correspondence analysis, because it gives uniform weights to all the points. The visual map constructed by taxicab correspondence analysis has a larger sweep and clearer perspective than the map obtained by correspondence analysis. Two examples are provided.
Gibney as Surgeon-in-Chief: The Earlier Years, 1887–1900
Authors: Levine David B.
Published: June 2006

Dr. James Knight's death in 1887 resulted in a change of course for the Hospital for the Ruptured and Crippled (renamed the Hospital for Special Surgery in 1940). The Board of Managers appointed Dr. Virgil Pendleton Gibney as the second Surgeon-in-Chief. The hospital's professional staff was expanded with introduction of surgical procedures. Gibney, raised in Kentucky, was trained under Lewis H. Sayre, M.D., a prominent orthopaedic surgeon at Bellevue Hospital. Dr. Gibney introduced the first residency training, expanded the physical plant, and continued to care for the disabled children in the hospital while maintaining a private practice outside the hospital. He was one of the founding members of the American Orthopaedic Association and served as its first president. He was the only member ever to serve as president twice, the second time in 1912.
Rayleigh wave phase velocity analysis of the Ross Sea, Transantarctic Mountains, and East Antarctica from a temporary seismograph array
Authors: Lawrence Jesse F. , Wiens Douglas A. , Nyblade Andrew A. , Anandakrishnan Sridhar , Shore Patrick J. , Voigt Donald
Published: June 2006

This study analyzes Rayleigh wave phase velocities from the Ross Sea (RS) region of the West Antarctica rift system, the Transantarctic Mountains (TAMs), and part of East Antarctica (EA). The Transantarctic Mountain Seismic Experiment deployed 41 three‐component broadband seismometers, which provide new data for high‐resolution two‐dimensional maps demonstrating crustal and uppermost mantle seismic velocity anomalies. The short‐period (16–25 s) phase velocity maps are consistent with changes in crustal thickness from ∼20 km under the RS to ∼35 km beneath the TAMs and EA. Long‐period (75–175 s) phase velocity maps indicate high mantle velocities beneath EA, low velocity beneath the RS, and a transition between the two between 50 and 150 km inland. The EA phase velocities in the region adjacent to the TAM exhibit a directional pattern consistent with 2 ± 1% azimuthal anisotropy with a NE‐SW fast direction. The structure of the RS is similar to continental rifting environments elsewhere, with a pronounced low‐velocity zone in the ∼80–220 km depth range, whereas EA shows a typical continental cratonic structure with high velocities between the 80 and 220 km depth range.
Measurement of differential rupture durations as constraints on the source finiteness of deep‐focus earthquakes
Authors: Warren Linda M. , Silver Paul G.
Published: June 2006

The physical mechanism of deep earthquakes can be constrained by identifying their fault planes. Resolving the fault plane ambiguity is a classical problem in seismology, and we present a method to distinguish the fault plane using observations of source finiteness. Source finiteness is observable on seismograms at different azimuths and distances, for single‐event ruptures, as variations in the apparent rupture duration and, for complex ruptures, as differences in the traveltime delay between subevents. For each earthquake, the rupture duration (or traveltime delay) will be shortest in the direction of rupture propagation and longest in the opposite direction. Rather than measuring the actual rupture duration at each station, we use a cross‐correlation technique that includes a stretching factor to measure the differential rupture duration between each pair of stations. These differential measurements then allow us to identify the rupture direction, rupture velocity, and fault plane for each earthquake. First, we test the method on two synthetic earthquakes, which represent earthquakes composed of one and two events. The method works well for both examples, although attenuation can bias the determined rupture direction for the single‐event case. Next, we apply this method to P waves from broadband seismograms from four intermediate‐ and deep‐focus earthquakes composed of two subevents: the 23 January 1997 Bolivian earthquake (MW 7.1, 276 km depth), the 27 October 1994 earthquake south of the Fiji Islands (MW 6.7, 549 km depth), the 21 July 1994 Japan Sea earthquake (MW 7.3, 471 km depth), and the 11 November 1998 Fiji Islands earthquake (MW 6.3, 149 km depth). Each focal mechanism contains a subvertical and a subhorizontal nodal plane. For three of the events, our analysis shows that rupture propagated subhorizontally, and we identify the subhorizontal nodal plane as the fault plane. For the smallest event, the rupture azimuth, but not the rupture dip, is well constrained, and we cannot conclusively identify the fault plane. Rupture velocities vary from 0.18 to 0.63 of the local P wave velocity.
Investigation of Brazil Current rings in the confluence region
Authors: Lentini Carlos A. D. , Goni Gustavo J. , Olson Donald B.
Published: June 2006

TOPEX/Poseidon‐derived along track SHA, climatological temperature, and salinity fields were used within a two‐layer scheme to estimate the depth of the 8°C isotherm in the southwestern Atlantic. These fields were used to monitor the formation and characteristics of the Brazil Current warm‐core anticyclonic rings shed by the first meander trough after poleward excursions of the Brazil Current (BC). Results reveal that 40 warm‐core rings were shed by the BC between January 1993 and October 1998. The observed lifetime ranges between 1 and 4 months, with a mean value of approximately 2 months. At any given time, two to three anticyclonic rings coexisted in the Brazil‐Malvinas confluence region. Most of the rings drifted southward without coalescing with their parent current. Only four rings were identified as being reabsorbed by the BC front after they were shed. No evidence of propagation or absorption of these anticyclones into the eastern limb of the subtropical gyre was observed. These rings have a mean horizontal length scale of 55 km, mean upper‐layer thickness of 260 m, and mean translation speed of 10 km d−1. Volume anomaly and available potential energy computations showed a mean value of 3.6 × 1012 m3 and 2.5 × 1015 J, respectively. The upper layer transport of the BC was also computed, and a relationship between variations in the southward transport and ring shedding activity was examined. Computation of the heat flux anomaly of the BC rings is estimated to be approximately 0.045 PW per annum. Compilation of these results indicates that warm‐core rings created by meandering boundary current extensions in different regions are generally similar.
Morphodynamic evolution of double‐barred beaches
Authors: Klein M. D. , Schuttelaars H. M.
Published: June 2006

The linear and nonlinear morphological behavior of double‐barred coastal systems under the forcing of obliquely incident waves is studied using a nonlinear numerical model. The linearly most unstable bed forms consist of crescentic patterns (rip channels), whose spacing depends on the magnitude of the longshore current velocity. Using the nonlinear model, six morphodynamic experiments have been performed with various initial bed perturbations in order to assess, among others, the influence of the initial bed perturbation on the morphodynamic evolution. The nonlinear experiments have been pursued well into the nonlinear regime, showing that after a phase of initial exponential growth, a highly dynamic behavior is observed and no equilibrium state is reached. The spacings predicted with the linear stability analysis are observed during the exponential phase of the nonlinear experiments. In the dynamic phase, however, four to seven modes significantly contribute to the resulting bed features. In this final stage, the apparent wavelength of 1000 m of the resulting bed forms on the inner bar is quite insensitive to the initial bed perturbation. On the outer bar it seems that the longer the wavelength of the initial bed perturbation, the longer the wavelength of the final bed forms in the dynamic phase and the larger the migration celerity. In general, the bed forms can be characterized as crescentic or undulating bed patterns. Good correspondence between simulated and observed spacings, shapes and migration celerities are found.
A model study of the seasonal mixed layer heat budget in the equatorial Atlantic
Authors: Peter Anne‐Charlotte , Le Hénaff Matthieu , du Penhoat Yves , Menkes Christophe E. , Marin Frédéric , Vialard Jérôme , Caniaux Guy , Lazar Alban
Published: June 2006

In the present study, the physical processes that control the seasonal cycle of sea surface temperature in the tropical Atlantic Ocean are investigated. A high‐resolution ocean general circulation model is used to diagnose the various contributions to the mixed layer heat budget. The simulation reproduces the main features of the circulation and thermal structure of the tropical Atlantic. A close examination of the mixed layer heat budget is then undertaken. At a first order, the mixed layer temperature balance in the equatorial band results from cooling by vertical processes and heating by atmospheric heat fluxes and eddies (mainly tropical instability waves). Cooling by subsurface processes is the strongest in June–August, when easterlies are strong, with a second maximum in December. Heating by the atmosphere is maximum in February–March and September–October, whereas eddies are most active in boreal summer. Unlike previous observational studies, horizontal advection by low‐frequency currents plays here only a minor role in the heat budget. Off equator, the sea surface temperature variability is mainly governed by atmospheric forcing all year long, except in the northeastern part of the basin where strong eddies generated at the location of the thermal front significantly contribute to the heat budget in boreal summer. Finally, comparisons with previously published heat budgets calculated from observations show good qualitative agreement, except that subsurface processes dominate the cooling over zonal advection in the present study.
Satellite‐based high‐resolution global optimum interpolation sea surface temperature data
Authors: Kawai Yoshimi , Kawamura Hiroshi , Takahashi Shin , Hosoda Kohtaro , Murakami Hiroshi , Kachi Misako , Guan Lei
Published: June 2006

We have produced global daily high‐resolution analytical sea surface temperature (SST) data for the latter half of the 1990s from four kinds of different satellite SST products, including microwave SST, from 1998. The optimum interpolation (OI) method is applied to SST anomaly from climatological annual signal with the decorrelation scales of the first‐guess error of less than 200 km. The effective spatial resolution of the OI SST is a few hundred kilometers due to these scales. The monthly mean difference between this OI SST and in situ SST averaged in 60°S–60°N are almost within ±0.1 K. The root‐mean square differences between them are less than 0.6 K in most of open oceans. From 1995 to 1997, when only one or two infrared SST products are available, the difference from the in situ SST tends to be negative because one of the infrared SST used here has a slight cool bias throughout the period. This bias decreases or becomes positive upon being combined with other satellite SST data. Fine spatial structure that cannot be seen in a 1°‐grid analytical SST is clearly represented, and mesoscale spatial variations with a wavelength of 400–500 km are captured in this OI SST. The temporal variability of the OI SST is also examined at a few points using a wavelet technique. The OI SST can nearly capture variations in the period of more than 1 month, although there are still some differences in the variations between the OI SST and buoy SST.
Accuracy of high‐rate GPS for seismology
Authors: Elósegui P. , Davis J. L. , Oberlander D. , Baena R. , Ekström G.
Published: June 2006

We built a device for translating a GPS antenna on a positioning table to simulate the ground motions caused by an earthquake. The earthquake simulator is accurate to better than 0.1 mm in position, and provides the "ground truth" displacements for assessing the technique of high‐rate GPS. We found that the root‐mean‐square error of the 1‐Hz GPS position estimates over the 15‐min duration of the simulated seismic event was 2.5 mm, with approximately 96% of the observations in error by less than 5 mm, and is independent of GPS antenna motion. The error spectrum of the GPS estimates is approximately flicker noise, with a 50% decorrelation time for the position error of ∼1.6 s. We find that, for the particular event simulated, the spectrum of surface deformations exceeds the GPS error spectrum within a finite band. More studies are required to determine whether a generally optimal bandwidth exists for a target group of seismic events.
Western Scotia Sea margins: Improved constraints on the opening of the Drake Passage
Authors: Lodolo Emanuele , Donda Federica , Tassone Alejandro
Published: June 2006

We present a revised tectonic interpretation (from ∼28 Ma to 3.2 Ma) of the western sector of the Scotia Sea, incorporating new multichannel seismic reflection profiles and magnetic anomaly identifications for the continental margin off the Tierra del Fuego Island, and available complementary data for the conjugate margin of the northwestern flank of the South Scotia Ridge. Seismic profiles show a remarkable diversity of the pair of conjugate passive margins of the western Scotia Sea in both their morphology and structural framework. The Tierra del Fuego continental margin can be related to a classic rifted passive margin, while the southwestern margin of the Scotia Sea is characterized by steep slopes mostly generated by subvertical faults that abruptly separate the continental crust of the South Scotia Ridge from the oceanic crust of the western Scotia Sea. This structural difference was caused by intense strike‐slip tectonism, mostly concentrated along the modern South Scotia Ridge since the early development of the western Scotia Sea. We find evidence for a previously unrecognized magnetic anomaly 10 (∼28 Ma) at the foot of the Tierra del Fuego continental margin; the same anomaly is present at the conjugate northern flank of the South Scotia Ridge. The timing of events leading to the earliest development of the western Scotia Sea, which determined the opening of the Drake Passage is important because this gateway opening had a profound effect on global circulation and climate. The thickness and the distribution of the sedimentary cover overall in the abyssal plain off the two western Scotia Sea margins is different. This is due to the different regimes of the bottom‐current flows which affected the western Scotia Sea, both in the past and in the present time.
Mitogenic modulation of Ca2+‐activated K+ channels in proliferating A7r5 vascular smooth muscle cells
Authors: Si Han , Grgic Ivica , Heyken Willm‐Thomas , Maier Tanja , Hoyer Joachim , Reusch Hans‐Peter , Köhler Ralf
Published: June 2006

Modulation of Ca2+‐activated K+ channels (KCa) has been implicated in the control of proliferation in vascular smooth muscle cells (VSMC) and other cell types. In the present study, we investigated the underlying signal transduction mechanisms leading to mitogen‐induced alterations in the expression pattern of intermediate‐conductance KCa in VSMC.

Regulation of expression of IKCa/rKCa3.1 and BKCa/rKCa1.1 in A7r5 cells, a cell line derived from rat aortic VSMC, was investigated by patch‐clamp technique, quantitative RT–PCR, immunoblotting procedures, and siRNA strategy.

PDGF stimulation for 2 and 48 h induced an 11‐ and 3.5‐fold increase in rKCa3.1 transcript levels resulting in a four‐ and seven‐fold increase in IKCa currents after 4 and 48 h, respectively. Upregulation of rKCa3.1 transcript levels and channel function required phosphorylation of extracellular signal‐regulated kinases (ERK1/2) and Ca2+ mobilization, but not activation of p38‐MAP kinase, c‐Jun NH(2)‐terminal kinase, protein kinase C, calcium‐calmodulin kinase II and Src kinases.

In contrast to rKCa3.1, mRNA expression and functions of BKCa/rKCa1.1 were decreased by half following mitogenic stimulation. Downregulation of rKCa1.1 did not require ERK1/2 phosphorylation or Ca2+ mobilization.

In an in vitro‐proliferation assay, knockdown of rKCa3.1 expression by siRNA completely abolished functional IKCa channels and mitogenesis.

Mitogen‐induced upregulation of rKCa3.1 expression is mediated via activation of the Raf/MEK‐ and ERK‐signaling cascade in a Ca2+‐dependent manner. Upregulation of rKCa3.1 promotes VSMC proliferation and may thus represent a pharmacological target in cardiovascular disease states characterized by abnormal cell proliferation.

British Journal of Pharmacology (2006) 148, 909–917. doi:10.1038/sj.bjp.0706793
Effects of ginseng saponins isolated from Red Ginseng roots on burn wound healing in mice
Authors: Kimura Yoshiyuki , Sumiyoshi Maho , Kawahira Kazuhiro , Sakanaka Masahiro
Published: June 2006

We recently demonstrated that ginsenoside Rb1 (C54H92O23, molecular weight 1108) isolated from ginseng, when intravenously infused into rats with permanent middle cerebral artery occlusion, reduced cerebral infarct volume and ameliorated place navigation disability of the animals, through an anti‐apoptotic action and possibly promotion of vascular regeneration. To investigate the ginsenoside Rb1‐mediated vascular regeneration in vivo in a more easily accessible experimental systems, we made a burn wound on the backs of mice and topically applied either Vaseline (vehicle) alone or Vaseline containing low doses of ginsenoside Rb1 to the wound.

Surprisingly, we found that ginsenoside Rb1 at low concentrations (100 pg g−1, 1 pg g−1 and 10 fg g−1 ointment) exhibited the strongest burn wound‐healing action. Furthermore, ginsenoside Rb1 (100 fg–1 ng per wound) increased neovascularization in the surrounding tissue and production of vascular endothelial growth factor (VEGF) and interleukin (IL)‐1β from the burn wound, compared to those mice with burn wounds treated with vehicle alone.

In human keratinocyte cultures (HaCaT cells), ginsenoside Rb1 (100 fg ml−1 to 1 ng ml−1) enhanced VEGF production induced by IL‐1β and expression of hypoxia‐inducible factor (HIF)‐1α.

These findings suggest that the promotion of burn wound healing by ginsenoside Rb1 might be due to the promotion of angiogenesis during skin wound repair via the stimulation of VEGF production, through the increase of HIF‐1α expression in keratinocytes, and due to the elevation of IL‐1β resulting from the macrophage accumulation in the burn wound.

British Journal of Pharmacology (2006) 148, 860–870. doi:10.1038/sj.bjp.0706794
Dual effect of calmodulin on store‐operated Ca2+‐permeable cation channels in rabbit portal vein myocytes
Authors: Albert Anthony P , Liu Min , Large William A
Published: June 2006

We have previously described a Ca2+‐permeable non‐selective cation channel in freshly dispersed rabbit ear artery myocytes, which is activated by agents that deplete internal Ca2+ stores and also by protein kinase C (PKC). In the present study, we investigated the effect of calmodulin (CaM) on store‐operated channels (SOCs) with electrophysiological techniques.

Bath application of the CaM inhibitor calmidazolium (CMZ) to quiescent cells produced transient activation of SOC activity in cell‐attached patches. CMZ produced a dual effect on cyclopiazonic acid (CPA)‐evoked SOCs by initially inducing an increase in mean open probability (NPo) and subsequently producing a marked inhibition of SOC activity. In contrast, SOCs activated by the cell‐permeable Ca2+ chelator 1,2‐bis (2‐aminophenoxy)ethane‐N‐N,N′,N′‐tetraacetic acid (BAPTA‐AM) were inhibited by CMZ.

In inside‐out patches where SOCs were activated by CPA or the PKC activator phorbol‐12,13‐dibutyrate (PDBu), bath application of CaM induced an initial inhibition followed by an increase in SOC activity. In contrast, CaM only enhanced BAPTA‐AM‐evoked SOC activity in inside‐out patches.

Bath application of CaM to the cytoplasmic surface of quiescent inside‐out patches evoked single channel currents with biophysical properties similar to SOCs.

The inhibitory action of CaM on PDBu‐induced SOC activity was inhibited by the calmodulin‐dependent kinase II (CaM kinase II) inhibitor autocamtide‐related inhibitory peptide (AIP) but not by inhibitors of calcineurin or myosin light chain kinase (MLCK). In addition, CaM‐evoked channel currents were inhibited by coapplication of purified CaM kinase II but not by inhibitors of CaM kinase II, calcineurin or MLCK.

With whole‐cell and cell‐attached recording, bath application of the CaM kinase II inhibitors KN93 and AIP evoked SOCs in unstimulated myocytes.

These results indicate that CaM has pronounced dual inhibitory and excitatory actions on SOCs with the inhibitory effect of CaM mediated by CaM kinase II. Moreover, the present work provides strong evidence that CaM has an important role in activating SOCs, possibly through a direct action on channel/associated proteins.

British Journal of Pharmacology (2006) 148, 1001–1011. doi:10.1038/sj.bjp.0706797
Activation of 5‐HT3 receptors in the rat and mouse intestinal tract: a comparative study
Authors: Chetty Navinisha , Irving Helen R , Coupar Ian M
Published: June 2006

This study provides a comprehensive evaluation of 5‐HT3 receptor functional distribution in both the rat and mouse intestinal tract.

5‐HT3A−S receptor splice variant mRNA was expressed throughout the intestine of the rat and mouse; the 5‐HT3A−L variant being more common in the rat.

5‐HT, m‐CPB, 1‐PBG and 2‐methyl‐5‐hydroxytryptamine (2m5‐HT) induced contraction in the jejunum, ileum, proximal colon and distal colon of the rat (pEC50 range: 2m5‐HT, 5.86±0.40 to m‐CPB, 7.47±0.27) and mouse (pEC50 range: 1‐PBG, 5.34±0.06 to m‐CPB, 6.49±0.14) in the presence of nontarget 5‐HT receptor antagonists, methysergide (1 μM) and GR125487 (0.1 μM). The rank orders of potency in the four regions of the rat and mouse intestine were concordant with the accepted order and the responses to 5‐HT were inhibited by ondansetron (0.1 μM).

5‐HT3‐induced contractions to 5‐HT were reduced by tetrodotoxin (1 μM). Pargyline (10 μM) and fluoxetine (1 μM) potentiated responses in the rat jejunum. Atropine (0.1 μM) potentiated 5‐HT3‐induced responses in the rat jejunum (Emax 49–65%), but attenuated responses in most other regions of the rat and mouse (e.g. mouse ileum: Emax 57–26%). In the rat jejunum, L‐NAME (100 μM) mimicked the effect of atropine, hexamethonium (100 μM) suppressed 5‐HT3‐induced responses, but tachykinin receptor antagonists were without effect.

It is concluded that functional 5‐HT3 receptors are present in nerves along the length of the rat and mouse intestinal tract. The mouse proximal colon was found to discriminate 5‐HT3 receptor agonist profiles better than any other region in the rat or mouse. The rat jejunum shows evidence of 5‐HT uptake and inactivation processes as well as inhibitory nitrergic and nontachykinin excitatory pathways associated with the 5‐HT3‐induced response.

British Journal of Pharmacology (2006) 148, 1012–1021. doi:10.1038/sj.bjp.0706802
Magnetocaloric effect in Mn5Ge3−xSix pseudobinary compounds
Authors: Liu X. B. , Altounian Z.
Published: June 2006

Structure and magnetic properties of Mn5Ge3−xSix pseudobinary compounds with x=0–1.5 were studied by x-ray diffraction and magnetic measurements. The compounds retain the hexagonal D88-type structure with a space group P63∕mcm, and their lattice parameters decrease from a=7.204(2)Å and c=5.028(2)Å to a=7.084(2)Å and c=4.945(3)Å with increasing Si content. Wigner-Seitz cell volume calculations indicate that Mn site volumes and Mn-Mn atomic distances decrease with increasing x, which influences the exchange interaction. All the compounds are ferromagnetic and their Curie temperatures, TC, decrease from 298 to 252K as the Si content is increased. In addition, the average atomic magnetic moment of Mn (at 5K) decreases from 2.64 to 2.35μB with increasing x from 0 to 1.5. The magnetocaloric effect is evaluated by measuring the isothermal magnetic entropy change, ΔSm, using the appropriate thermodynamic Maxwell relation. The peak value of ΔSm ranges from about 9.0to6.3J∕kgK for x=0–1.5 near their TC under an external magnetic field change of 5T. On the other hand, ΔSm peaks broaden with increasing x, consistent with the less sharp change of magnetization near TC. We show that the phenomena can be ascribed to the weakening of the exchange interaction as the Mn-Mn separation is reduced upon the addition of Si atoms.
Development of micromagnetic bearing motors with suppressed magnetic coupling effect for small form factor optical drives
Authors: Wang Chien-Chang , Yao Y. D. , Wang Shyh-Jier
Published: June 2006

The aim of this paper was to design a micromagnetic bearing (MMB) motor for small form factor optical drives. A MMB motor was developed with inner and outer magnetic-ring stack structure of high permeability. These rings were arranged on the shaft above the permanent magnet of the rotor and the stator. The magnetic force between the MMB, the permanent magnet, and the stator induced the magnetic coupling effect that generated the demon friction torque loss. However, the loss was controlled well under 1.93×10−4Nm by the proposed approach, so that the good stable system was achieved. After suppressing the loss caused by the magnetic coupling effect, the shaft can be rotated without any frictional contacts in radial direction, the running current was around 0.18A, and the maximum speed was around 1850rpm. It shows that the MMB demonstrates the lower friction torque loss in comparison with the conventional microball bearing (MBB). Moreover, the radial vibration of our device is 21% lower than the conventional MBB type. To verify the performance of the provided system, both the computer simulation and the experiment were performed.
Temperature dependence of the magnetic properties in LaMnO3+δ
Authors: Palomares F. J. , Pigazo F. , Romero J. J. , Cuadrado R. , Arroyo A. , García M. A. , Hernando A. , Cortés-Gil R. , González-Calbet J. M. , Vallet-Regí M. , González J. M. , Alonso J. M.
Published: June 2006

Data are presented on the thermal dependence of the hysteretic properties of cationic vacancies including manganite samples of composition LaMnO3+δ (δ=0.05 and 0.12). Our results evidence the presence in both samples of two magnetic phases having ferro- and antiferromagnetic orders, respectively. The temperature dependence of the coercivity and relaxational properties of the samples is closely linked to the connectivity of the magnetic moment bearing Mn3+–Mn4+ ferromagnetic clusters that demagnetize independently in the case of the δ=0.05 sample and collectively in that of the δ=0.12 one, as evidenced from the activation volume results (δ=0.05) which yielded a size of the same order magnitude as that obtained in previous works for the Mn3+–Mn4+ ferromagnetic cluster size.
Controlled fabrication of nickel perpendicular nanocontacts using focused ion beam milling
Authors: Wei Hong-Xiang , Langford R M. , Han Xiufeng , Coey J. M. D.
Published: June 2006

A method for the controlled fabrication of a nickel perpendicular nanocontact with diameters less than 5 nm is reported. The method involves milling pores through the 100 nm thick silicon nitride membrane using a focused ion beam, and depositing thin Ni film on the both side of the silicon nitride membrane. The shape of the resulting pore and nanocontact size is determined by the initial hole size and redeposition of the sputtered material onto the sidewalls of the holes. A sub-5 nm Ni nanocontact was prepared and the I-V and R-H characteristics measured.
Current effects in electronically phase-separated Pr0.7Pb0.3MnO3 single crystals
Authors: Li Run-Wei , Zhou Xin , Belik Alexei , Miki Kazushi , Shen Bao-Gen
Published: June 2006

In electronically phase-separated Pr0.7Pb0.3MnO3 single crystals, current effects have been investigated systematically by combining voltage-current and specific-heat measurements. Below the metal-insulator transition temperature, the resistance increased with current at first, then decreased when the current was above a threshold value. The critical current deceased with increasing temperature and could be modulated dramatically by applying a magnetic field. By combining heat measurements, we found that Joule heat effects seem not able to be completely responsible for the nonlinear current effects. Self-optimized conducting channels or phase separation induced by the current were proposed to be other possible underlying physical processes.
Spin-dependent two-level resistance fluctuations in underoxidized tunnel junctions
Authors: Ventura J. , Teixeira J. , Pogorelov Yu. G. , Sousa J. B. , Ferreira R. , Freitas P. P.
Published: June 2006

Magnetic tunnel junctions (MTJs) with partially oxidized 9 Å AlOx barriers were recently shown to have the characteristics needed for magnetoresistive sensors in high-density storage devices (tunneling magnetoresistance ∼20%; RA∼0.5Ωμm2). Here we study the electrical transport in such low-resistance, underoxidized magnetic tunnel junctions. Under a low bias current, the tunnel magnetoresistance ratio reveals jumps between two closely separated levels, an effect associated with spin dependent transport through localized defects in the insulating barrier. We further show that dielectric breakdown at high applied electrical current is of an extrinsic nature. Temperature-dependent measurements of the electrical resistance (R) of MTJs (300-20 K) with extremely small oxidation times reveal a metallic-like behavior (dR∕dT>0), although a large magnetoresistive ratio is still observed (16% at T=300K and 28% at T=20K).