bluuebunny/crossref_metadata_2025 huggingface dataset:
Transferring HR practices within multinational corporations
Authors: Björkman Ingmar , Lervik Jon E.
Published: October 2007

There is extensive evidence that planned transfers of management practices by the headquarters of multinational corporations (MNCs) to foreign subsidiaries are not always successful. In this article, we outline a model of factors influencing the transfer of HR practices to MNC units abroad. The article has two main contributions. First, we develop a more holistic understanding of the outcome of HR practice transfer as encompassing three dimensions: implementation, internalisation and integration. Second, we expand current explanations of transfers of practices to foreign units. We argue that transfer of HR practices is a social process where the governance mechanisms used by the MNC, characteristics of the subsidiary HR systems, the social relationship between the subsidiary and MNC headquarters, and the transfer approach taken by headquarters management will influence the outcome of the process.
Creating social capital in MNCs: the international human resource management challenge
Authors: Taylor Sully
Published: October 2007

Social capital has assumed a critical role in the successful implementation of global strategy for multinational companies (MNCs). The article focuses on the ways in which the international human resource management (IHRM) system and those responsible for it influence the creation and utilisation of social capital in MNCs. It examines the challenges posed to IHRM by the wide diversity of definitions and manifestations of social capital found in the multiple cultural contexts of the global business environment and provides a framework on how to approach the cultural influences on the definitions and behavioural expressions of social capital. It also critically assesses the recommendations that have been made regarding developing social capital in MNCs, the competencies most critical to the ability to develop social capital in multiple cultural settings, and provides a set of recommendations for future research in this area.
Uncovering competitive and institutional drivers of HRM practices in multinational corporations
Authors: Farndale Elaine , Paauwe Jaap
Published: October 2007

Current international human resource management (IHRM) literature focusing on multinational corporations (MNCs) presents evidence of both similarities and differences in the HR practices adopted in different global locations. However, the drivers behind this duality require more detailed investigation. This article focuses on exploring why MNCs position themselves within global markets as they do, exploring how extant theory can help explain the drivers behind both global and national HR practices. Based on a worldwide sample of in‐depth interview‐based case studies of well‐known MNCs, we explore the ways in which different firms react to both institutional and competitive pressures in selecting their approach to HRM. The findings uncover a differentiation between external global competitive isomorphic pressures, external national institutional isomorphic pressures, and internal processes of strategic choice and competitive differentiation. It is suggested that MNCs face all three drivers of HRM simultaneously, leading to different patterns of practice adoption, adaptation and innovation.
Analytical performances of the d‐dimer assay for the Immulite 2000 automated immunoassay analyser
Authors: LIPPI G. , SALVAGNO G. L. , ROSSI L. , MONTAGNANA M. , FRANCHINI M. , GUIDI G. C.
Published: November 2007

We evaluated the analytical performances of a new commercial chemiluminescent enzyme immunometric assay for d‐dimer measurement on the Immulite 2000 automated analyser. The within‐ and between‐run coefficients of variations for low, intermediate and high d‐dimer concentrations ranged from 2.2% to 5.1% and from 2.9% to 6.0% respectively. The assay was proven linear in a range of d‐dimer concentrations comprised between 324 and 7602 ng/ml. Comparison of samples collected in either 0.109 mol/l sodium citrate or lithium–heparin tubes by Bland–Altman plots and nonparametric regression analysis (y = 0.858x − 39, r = 0.997; P < 0.0001) revealed a minimum bias, almost completely attributable to the dilution effect of the anticoagulant. Results of 56 outpatients’ citrated plasma samples analysed with the Immulite 2000 d‐dimer assay were compared with those of the current reference commercial immunoassay on the Mini Vidas Immunoanalyser. Although the nonparametric regression according to the method of Passing and Bablok and the relative Spearman's correlation coefficient was satisfactory (Immulite = 1.001 × Vidas − 181; r = 0.937, P < 0.001), some random discrepancies could be observed in Bland–Altman plots analysis. The analytical accuracy, calculated as the area under the Receiver Operating Characteristic (ROC) curve (AUC), was 0.961 (P < 0.0001). On the basis of the results of the present evaluation, we conclude that the analytical performances and the main technical features of new Immulite 2000 d‐dimer assay make it a suitable method for the rapid quantification of d‐dimer in clinical laboratories.
Acid activation of protyrosinase from Aspergillus oryzae: homo‐tetrameric protyrosinase is converted to active dimers with an essential intersubunit disulfide bond at acidic pH
Authors: Tatara Yota , Namba Takeshi , Yamagata Youhei , Yoshida Takashi , Uchida Takafumi , Ichishima Eiji
Published: October 2007

Aspergillus oryzae protyrosinase (pro‐TY) has a unique feature that the proenzyme is activated under conditions of acidic pH. The pro‐TY was inactive at pH 7.0. The latent enzyme was activated at pH 3.0, and was slightly activated by sodium dodecyl sulfate (SDS). The molecular masses of the pro‐TY and acid‐activated tyrosinase (acid‐TY) were 266 and 165 kDa, respectively, as estimated by gel‐filtration chromatography. The CD spectra showed that the tertiary and/or quaternary structure was changed after the acid activation. On the basis of these results, we deduce that the intersubunit polar interaction is disrupted at pH 3.0, and that the tetrameric pro‐TY dissociates to dimers. Tryptophan fluorescence spectra and binding assay of 8‐anilino‐1‐naphthalene sulfonic acid (ANS) suggested that hydrophobic amino acid residues of the active site were exposed to solvent after acid treatment. It was likely that Cys108 formed an intermolecular disulfide bond between the subunits of dimeric acid‐TY. The dimerization of acid‐TY involving the intermolecular disulfide bond is essential for the activity.
The significance of Nrf2 pathway in (photo)‐oxidative stress response in melanocytes and keratinocytes of the human epidermis
Authors: Marrot Laurent , Jones Christophe , Perez Philippe , Meunier Jean‐Roch
Published: October 2007

The expression of genes encoding antioxidant and/or phase 2 detoxifying enzymes can be enhanced in response to various environmental stresses. The main transcription factor involved in this response is nuclear factor erythroid 2‐related factor 2 (Nrf2). Nrf2 activity is negatively regulated by the protein Kelch‐like‐Ech‐associated‐protein 1 (Keap1). While the roles of Nrf2 and phase 2 genes in chemoprevention of carcinogenesis have been well described; only few studies have dealt with their role in skin cancer. Normal human keratinocytes (NHK) and melanocytes (NHM) were treated by chemical inducers of the Nrf2 pathway or by small interfering RNAs (siRNA) used to knock down Keap1 mRNA. The above treatments resulted in significant stimulation of NQO‐1 (NADPH‐Quinone‐Oxidoreductase 1) gene expression. GCL (γ‐Glutamyl‐cysteinyl‐ligase) gene was also induced but interestingly increased mRNA encoding the catalytic, heavy subunit GCLC was mainly stimulated in NHK, whereas the mRNA encoding the modifier, light subunit GCLM was mostly induced in NHM. HO‐1 (Heme Oxygenase 1) gene induction was relatively strong in NHM, but generally absent in NHK, except when the cells were subjected to cytotoxic doses of the above chemicals. Exposure to solar UV (UVB + UVA, 300–400 nm) or to UVA alone (320–400 nm) confirmed this trend, but interestingly, at doses where cell growth reduction was comparable, UVA was generally more efficient than solar UV in inducing phase 2 genes. When siRNAs directed against Nrf2 were used, a strong down‐regulation of NQO‐1 expression was observed in both, NHM and NHK, whereas reduction of HO‐1 expression was mainly detected in NHM. To our knowledge, this is the first study comparing phase 2 gene modulation in NHK and NHM. The results hereby presented should contribute to a better understanding of the molecular mechanisms involved in skin adaptation to environmental stress.
Managing situations of acute blood loss with limited resources
Authors: FENTON PAUL M.
Published: October 2007

Death from acute blood loss is a common event in many parts of the world. Most of the half‐million‐plus maternal deaths worldwide are due to postpartum hemorrhage. While a state of general nonreportage exists in under‐resourced countries, it is clear that shortage of blood and trained clinical manpower are important causes of mortality, even for those lucky few who do make it to hospital. These factors and methods of resuscitation are considered in this review of the clinical scene and simple techniques available to treat hemorrhagic shock in under‐resourced countries.
Anemia in sepsis: the importance of red blood cell membrane changes
Authors: PIAGNERELLI MICHAEL , BOUDJELTIA KARIM ZOUAOUI , GULBIS BÉATRICE , VANHAEVERBEEK MICHEL , VINCENT JEAN‐LOUIS
Published: October 2007

Anemia is a common problem in acutely ill patients, especially in those who develop sepsis. There are many factors contributing to the development of anemia in these patients, including blood sampling and other losses, decreased red blood cell (RBC) synthesis, and possibly increased destruction. Increased RBC uptake may be due to changes in RBC morphology and the RBC membrane during inflammatory processes. In particular, a rapid increase in RBC sphericity correlated with a decreased surface carbohydrate membrane content and alterations in the lipid bilayer with increased peroxidation and phosphatidylserine exposure in the outer leaflet of the membrane. Better understanding of these alterations could facilitate new strategies to prevent the development of anemia in sepsis.
Saline versus balanced hydroxyethyl starch: does it matter?
Authors: BOLDT JOACHIM
Published: October 2007

The type of fluid used for correcting hypovolemia is still a matter of debate. There is increasing evidence that the choice of fluid may result in the development of hyperchloremic acidosis. As the base excess has been shown to be a valuable tool to diagnose circulatory derangements, development of metabolic acidosis by unbalanced fluids should be avoided because a low base excess caused by the choice of fluid is limiting this diagnostic armamentarium. Additionally, infusion of considerable amounts of volume with a non‐physiologic electrolyte composition appears to be associated with negative effects on coagulation, bleeding, blood flow, renal and gut function as well as on patient comfort. New light on this issue is shed by the introduction of a balanced volume replacement concept. This concept includes administration of balanced crystalloids and balanced colloids when necessary. As hydroxyethyl starch (HES), the colloid most commonly used in Europe, is solved in non‐physiologic saline solution, HES cannot fulfill the idea of a complete balanced volume replacement strategy. Preparing HES in a balanced solvent is supposed to reduce some substance‐specific negative effects. At present, information on the value of a total balanced volume replacement strategy is limited. Although it remains to be elucidated whether high doses or repetitive use of such a fluid replacement concept would be of advantage compared with a non‐balanced regimen with regard to mortality and morbidity, there are no arguments for refusing a balanced, plasma‐adapted volume replacement concept including a balanced HES.
Scars and Vortices Induced by Ship Bow and Shoulder Wave Breaking
Authors: Olivieri A. , Pistani F. , Wilson R. , Campana E. F. , Stern F.
Published: November 2007

Experimental data are provided for physical understanding and computational fluid dynamics (CFD) validation for the surface combatant David–Taylor model basin Model 5415 bow and shoulder wave breaking. A photographic study was conducted using 5.72m replica and 3.05m geosim models of Model 5415 over a range of Froude numbers (Fr) to identify Fr and scale effects on wave breaking and choose the best Fr for the local flow measurements, which include near- and far-field means and rms wave elevation and mean velocity under the breaking waves. The larger model and Fr=0.35 were selected due to the large extents of quasisteady plunging bow and spilling shoulder wave breaking. A direct correlation is shown between regions of wave slope larger than 17deg and regions of large rms in wave height variation. Scars characterized by sudden changes in the mean wave height and vortices induced by wave breaking were identified. Complementary CFD solutions fill the gaps in the relatively sparse measurements enabling a more complete description of the bow and shoulder wave breaking and induced vortices and scars. The combined results have important implications regarding the modeling of the bubbly flow around surface ships, especially for bubble sources and entrainment.
Initial beam size study for passive scatter proton therapy. II. Changes in delivered depth dose profiles
Authors: Polf Jerimy C. , Harvey Mark C. , Smith Alfred R.
Published: November 2007

In passively scattered proton radiotherapy, a clinically useful treatment beam is produced by spreading a small proton “pencil beam” extracted from the accelerator to create both a uniform dose profile laterally and a uniform spread‐out Bragg peak (SOBP) in depth. Lateral spreading and range modulation of the beam are accomplished using specially designed components within the treatment delivery nozzle. The purpose of this study was to determine how changes in the size of the initial proton pencil beam affect the delivery of dose with a passive scatter treatment nozzle. Monte Carlo calculations were used to study changes of the beam's in‐air energy distribution at the exit of the nozzle and the central axis depth dose profiles in water resulting from changes in the incident beam size. Our results indicate that the width of the delivered SOBP decreases as the size of the initial beam increases.
Radiological interpretation 2020: Toward quantitative image assessment
Authors: Boone John M.
Published: November 2007

The interpretation of medical images by radiologists is primarily and fundamentally a subjective activity, but there are a number of clinical applications such as tumor imaging where quantitative imaging (QI) metrics (such as tumor growth rate) would be valuable to the patient's care. It is predicted that the subjective interpretive environment of the past will, over the next decade, evolve toward the increased use of quantitative metrics for evaluating patient health from images. The increasing sophistication and resolution of modern tomographic scanners promote the development of meaningful quantitative end points, determined from images which are in turn produced using well‐controlled imaging protocols. For the QI environment to expand, medical physicists, physicians, other researchers and equipment vendors need to work collaboratively to develop the quantitative protocols for imaging, scanner calibrations, and robust analytical software that will lead to the routine inclusion of quantitative parameters in the diagnosis and therapeutic assessment of human health. Most importantly, quantitative metrics need to be developed which have genuine impact on patient diagnosis and welfare, and only then will QI techniques become integrated into the clinical environment.
Radioimmunotherapy with radioactive nanoparticles: First results of dosimetry for vascularized and necrosed solid tumors
Authors: Bouchat V. , Nuttens V. E. , Lucas S. , Michiels C. , Masereel B. , Féron O. , Gallez B. , Borght T. Vander
Published: November 2007

Radioimmunotherapy uses monoclonal antibodies that are still labeled with only one radioactive atom. The aim of this paper is to assess, by means of MCNPX simulations, the doses delivered around and throughout a solid tumor when the radioactive atom linked to each antibody is replaced by adiameter nanoparticle composed of numerous radionuclides. A new model for a spherical vascularized tumor has been developed in which the antibody distributions inside the tumor can be uniform or heterogeneous. It is also possible to simulate a central necrotic core inside the tumor where the concentration of radiolabeled antibodies is assumed to be zero. Dosimetry calculations have been performed for the beta‐emitting radionuclide. Preliminary results show that the irregularity of vasculature and the presence of a necrotic core have a noticeable influence on the deposited dose profiles. Moreover, with a total activity of 5 andfor tumor radii of 0.5 and, respectively, viable tumor cells can receive doses of up to, even if high nonuniformity of the total activity is observed in the tumor. These simulations still require accurate information about antibody characteristics and necrosis sizes but clearly confirm that the use of monoclonal antibodies conjugated to nanoparticles could lead to a considerable enhancement of treatment efficacy against cancer.
The GEANT4 toolkit for microdosimetry calculations: Application to microbeam radiation therapy (MRT)
Authors: Spiga J. , Siegbahn E. A. , Bräuer‐Krisch E. , Randaccio P. , Bravin A.
Published: November 2007

Theoretical dose distributions for microbeam radiation therapy (MRT) are computed in this paper using the GEANT4 Monte Carlo (MC) simulation toolkit. MRT is an innovative experimental radiotherapy technique carried out using an array of parallel microbeams of synchrotron‐wiggler‐generated x rays. Although the biological mechanisms underlying the effects of microbeams are still largely unknown, the effectiveness of MRT can be traced back to the natural ability of normal tissues to rapidly repair small damages to the vasculature, and on the lack of a similar healing process in tumoral tissues. Contrary to conventional therapy, in which each beam is at least several millimeters wide, the narrowness of the microbeams allows a rapid regeneration of the blood vessels along the beams’ trajectories. For this reason the calculation of the “valley” dose is of crucial importance and the correct use of MC codes for such purposes must be understood. GEANT4 offers, in addition to the standard libraries, a specialized package specifically designed to deal with electromagnetic interactions of particles with matter for energies down to 250 eV. This package implements two different approaches for electron and photon transport, one based on evaluated data libraries, the other adopting analytical models. These features are exploited to cross‐check theoretical computations for MRT. The lateral and depth dose profiles are studied for the irradiation of a 20 cm diameter, 20 cm long cylindrical phantom, with cylindrical sources of different size and energy. Microbeam arrays are simulated with the aid of superposition algorithms, and the ratios of peak‐to‐valley doses are computed for typical cases used in preclinical assays. Dose profiles obtained using the GEANT4 evaluated data libraries and analytical models are compared with simulation results previously obtained using the PENELOPE code. The results show that dose profiles computed with GEANT4's analytical model are almost indistinguishable from those obtained with the PENELOPE code, but some noticeable differences appear when the evaluated data libraries are used.
Stereotactic mammography imaging combined with 3D US imaging for image guided breast biopsy
Authors: Surry K. J. M. , Mills G. R. , Bevan K. , Downey D. B. , Fenster A.
Published: November 2007

Stereotactic X‐ray mammography (SM) and ultrasound (US) guidance are both commonly used for breast biopsy. While SM provides three‐dimensional (3D) targeting information and US provides real‐time guidance, both have limitations. SM is a long and uncomfortable procedure and the US guided procedure is inherently two dimensional (2D), requiring a skilled physician for both safety and accuracy. The authors developed a 3D US‐guided biopsy system to be integrated with, and to supplement SM imaging. Their goal is to be able to biopsy a larger percentage of suspicious masses using US, by clarifying ambiguous structures with SM imaging. Features from SM and US guided biopsy were combined, including breast stabilization, a confined needle trajectory, and dual modality imaging. The 3D US guided biopsy system uses a 7.5 MHz breast probe and is mounted on an upright SM machine for preprocedural imaging. Intraprocedural targeting and guidance was achieved with real‐time 2D and near real‐time 3D US imaging. Postbiopsy 3D US imaging allowed for confirmation that the needle was penetrating the target. The authors evaluated 3D US‐guided biopsy accuracy of their system using test phantoms. To use mammographic imaging information, they registered the SM and 3D US coordinate systems. The 3D positions of targets identified in the SM images were determined with a target localization error (TLE) of 0.49 mm. The component (x‐ray tube to image) of the TLE dominated with a of 0.47 mm. The SM system was then registered to 3D US, with a fiducial registration error (FRE) and target registration error (TRE) of 0.82 and 0.92 mm, respectively. Analysis of the FRE and TRE components showed that these errors were dominated by inaccuracies in the component with a of 0.76 mm and a of 0.85 mm. A stereotactic mammography and 3D US guided breast biopsy system should include breast compression for stability and safety and dual modality imaging for target localization. The system will provide preprocedural x‐ray mammography information in the form of SM imaging along with real‐time US imaging for needle guidance to a target. 3D US imaging will also be available for targeting, guidance, and biopsy verification immediately postbiopsy.
A strategy to objectively evaluate the necessity of correcting detected target deviations in image guided radiotherapy
Authors: Yue Ning J. , Kim Sung , Jabbour Salma , Narra Venkat , Haffty Bruce G.
Published: November 2007

Image guided radiotherapy technologies are being increasingly utilized in the treatment of various cancers. These technologies have enhanced the ability to detect temporal and spatial deviations of the target volume relative to planned radiation beams. Correcting these detected deviations may, in principle, improve the accuracy of dose delivery to the target. However, in many situations, a clinical decision has to be made as to whether it is necessary to correct some of the deviations since the relevant dosimetric impact may or may not be significant, and the corresponding corrective action may be either impractical or time consuming. Ideally this decision should be based on objective and reproducible criteria rather than subjective judgment. In this study, a strategy is proposed for the objective evaluation of the necessity of deviation correction during the treatment verification process. At the treatment stage, without any alteration from the planned beams, the treatment beams should provide the desired dose coverage to the geometric volume identical to the planning target volume (PTV). Given this fact, the planned dose distribution and PTV geometry were used to compute the dose coverage and PTV enclosure of the clinical target volume (CTV) that was detected from imaging during the treatment setup verification. The spatial differences between the detected CTV and the planning CTV are essentially the target deviations. The extent of the PTV enclosure of the detected CTV as well as its dose coverage were used as criteria to evaluate the necessity of correcting any of the target deviations. This strategy, in principle, should be applicable to any type of target deviations, including both target deformable and positional changes and should be independent of how the deviations are detected. The proposed strategy was used on two clinical prostate cancer cases. In both cases, gold markers were implanted inside the prostate for the purpose of treatment setup verification and were used to determine potential target deviations. To derive the detected CTV geometry from the planning CTV based on the locations of the gold markers, the CTV was approximated with an elastic semirigid body model. The derived CTV geometry and shape were confirmed with CBCT imaging. The evaluation results and the related mathematical equations and computational algorithm are presented. It is concluded that the proposed strategy is potentially useful in establishing objective criteria for the necessity of correction of the target deviations.
Improvement of the cine‐CT based 4D‐CT imaging
Authors: Pan Tinsu , Sun Xiaojun , Luo Dershan
Published: November 2007

An improved 4D‐CT utility has been developed on the GE LightSpeed multislice CT (MSCT) and Discovery PET/CT scanners, which have the cine CT scan capability. Two new features have been added in this 4D‐CT over the commercial Advantage 4D‐CT from GE. One feature was a new tool for disabling parts of the respiratory signal with irregular respiration and improving the accuracy of phase determination for the respiratory signal from the Varian real‐time positioning and monitoring (RPM) system before sorting of the cine CT images into the 4D‐CT images. The second feature was to allow generation of the maximum‐intensity‐projection (MIP), average (AVG) and minimum‐intensity‐projection (mip) CT images from the cine CT images without a respiratory signal. The implementation enables the assessment of tumor motion in treatment planning with the MIP, AVG, and mip CT images on the GE MSCT and PET/CT scanners without the RPM and the Advantage 4D‐CT with a GE Advantage windows workstation. Several clinical examples are included to illustrate this new application.
Commentary on “Figuring Physics/Rapid Evaporation”
Authors: Bohren Craig
Published: October 2007

The Figuring Physics that appeared in our April 2007 issue has drawn a number of responses. The question posed by Paul Hewitt in that piece had to do with evaporative cooling: “Consider four grams of boiling water poured onto a cold surface. Suppose one gram rapidly evaporates by absorbing 540 calories from the remaining three grams of water, ideally with no other heat transfer occurring. The remaining three grams will become (a) water at a temperature above 0°C, (b) water at 0°C, or (c) ice at 0°C.” Hewitt's answer (c) drew protests from readers who argued that this would violate the second law of thermodynamics.
Modeling Physics with Easy Java Simulations
Authors: Christian Wolfgang , Esquembre Francisco
Published: October 2007

Modeling has been shown to correct weaknesses of traditional instruction by engaging students in the design of physical models to describe, explain, and predict phenomena.1 Although the modeling method can be used without computers, the use of computers allows students to study problems that are difficult and time consuming, to visualize their results, and to communicate their results with others. This combination of computer modeling with theory and experiment can achieve insight and understanding that cannot be achieved with only one approach. This paper describes the Easy Java Simulations (Ejs) modeling and authoring tool and shows how it can be used to teach mechanics concepts with computer modeling.
Graphical Response Exercises for Teaching Physics
Authors: Bonham Scott
Published: October 2007

What is physics without graphs and diagrams? The web is becoming ubiquitous, but how can one expect students to make graphs and diagrams on the web? The solution is to extend functionality through Java applets. Four examples of exercises using the Physics Applets for Drawing (PADs) will illustrate how these can be used for physics instruction to evaluate student work and provide different levels of feedback.
Teaching Qualitative Energy-eigenfunction Shape with Physlets
Authors: Belloni Mario , Christian Wolfgang , Cox Anne J.
Published: October 2007

More than 35 years ago, French and Taylor1 outlined an approach to teach students and teachers alike how to understand “qualitative plots of bound-state wave functions.” They described five fundamental statements based on the quantum-mechanical concepts of probability and energy (total and potential), which could be used to deduce the shape of energy eigenfunctions. Despite these important and easy-to-follow statements, this approach has not been universally adopted in the teaching of quantum mechanics.2 For example, recent studies have shown that students' conceptual understanding of quantum mechanics on all levels is surprisingly lacking3 and that misconceptions are universal,4 including that of the relationship between the potential energy function and the resulting energy eigenfunction shape. At the same time, the teaching of quantum mechanical concepts in introductory physics has become increasingly important given the modern technological applications that are based on quantum theory (e.g., PET scans and MRIs). However, most treatments of quantum theory on the introductory level are cursory at best, leaving students with the impression that quantum mechanics is little more than abstract mathematics (a belief that remains with students in their future courses).
An Electromagnetic Induction Flashlight Experiment
Authors: Alden Emily , Kennedy Mark , Lorenzon Wolfgang , Smith Warren
Published: October 2007

In the last several years, the electronics industry has released hand generator-powered flashlights, which are advertised as the end of battery-powered flashlights. This has become possible because of recent advances in capacitor, magnet, and LED technology. Nevertheless, the physics behind these flashlights is fairly simple.
Teaching Information Evaluation and Critical Thinking Skills in Physics Classes
Authors: Popescu Adriana , Morgan James
Published: October 2007

The physics curriculum at all educational levels can be enriched to include tools for strengthening students' information evaluation skills. The Report of the Joint APS-AAPT Task Force on Graduate Education in Physics calls for such training to be part of graduate programs, but training to acquire these lifetime skills can be incorporated in the curriculum even before graduate level.
Teaching Thermodynamics and the Nature of Matter
Authors: Sobel Michael
Published: October 2007

The introductory course in college physics1 has been criticized as fragmented and lacking in a theme or “story” to tie together the disparate chapters.2 As physicists, we see it as highly organized and hierarchical, developing from the great principles of Newton, Maxwell, etc. But to the student, it's just the chapter on lost hikers, the chapter on cars crashing and sticking together, etc. The purpose of this paper is to consider a certain subset of introductory course subjects, one that seems, if anything, more fragmented than the rest, and then to suggest a way of presenting these subjects that constitutes a story.
The Moment of Inertia of a Rectangular Rod
Authors: Takeuchi Takao
Published: October 2007

Recently an inexpensive setup to obtain the moment of inertia of a rotating system was proposed by Peter E. Banks.1 An equally simple and inexpensive experiment to obtain the moment of inertia of a uniform rod is proposed in this paper. A rectangular rod with a hole somewhere in the rod was used for this purpose. The moment of inertia of a rectangular rod around the hole location was attempted. The experimental setup is shown in Fig. 1. Various supporting rods, clamps, and rubber stoppers to hold the rectangular rod in place at point p are not shown.
Quantity Versus Interval as a “Hinge” Concept
Authors: Nelson Jane , Nelson Jim
Published: October 2007

Column Editor's note: It is extremely important for students to develop definitions of terms from shared experiences such as the ones described by the Nelsons. Conceptual development in students will be hindered if we assume that dictionary definitions are adequate for developing understanding or that the meanings students associate with physics terms are accurate. Careful attention to what we say is crucial but we must also incorporate time for student discourse into instructional planning. Discussion of these “hinge” concepts requires close attention to addressing the linguistic problems associated with developing scientific literacy.
The need for additional safeguards in the informed consent process in schizophrenia research
Authors: Anderson K K , Mukherjee S D
Published: October 2007

The process of obtaining informed consent to participate in a clinical study presents many challenges for research conducted in a population of patients with schizophrenia. Morally valid, informed consent must include information sharing, decisional capacity, and capacity for voluntarism. This paper examines the unique features of schizophrenia that may threaten each of these elements of informed consent, and it proposes additional safeguards in the process of gaining informed consent from individuals with schizophrenia in order to maximise the decision-making potential of this patient population.
Teaching medical ethics to undergraduate students in post-apartheid South Africa, 2003–2006: Table 1
Authors: Moodley Keymanthri
Published: October 2007

The apartheid ideology in South Africa had a pervasive influence on all levels of education including medical undergraduate training. The role of the health sector in human rights abuses during the apartheid era was highlighted in 1997 during the Truth and Reconciliation Commission hearings. The Health Professions Council of South Africa (HPCSA) subsequently realised the importance of medical ethics education and encouraged the introduction of such teaching in all medical schools in the country. Curricular reform at the University of Stellenbosch in 1999 presented an unparalleled opportunity to formally introduce ethics teaching to undergraduate students. This paper outlines the introduction of a medical ethics programme at the Faculty of Health Sciences from 2003 to 2006, with special emphasis on the challenges encountered. It remains one of the most comprehensive undergraduate medical ethics programmes in South Africa. However, there is scope for expanding the curricular time allocated to medical ethics. Integrating the curriculum both horizontally and vertically is imperative. Implementing a core curriculum for all medical schools in South Africa would significantly enhance the goals of medical education in the country.
Uncomfortable implications: placebo equivalence in drug management of a functional illness
Authors: Evans H M , Hungin A P S
Published: October 2007

Using a fictional but representative general practice consultation, involving the diagnosis of irritable bowel syndrome in a patient who is anxious for some relief from the discomfort his condition entails, this paper argues that whenboth(a) a drug fails to out-perform placeboand(b) the condition in question is a functional illness with no demonstrable underlying pathology,thenthe action of the drug is not only no better than placebo, and it is also no different from it either. The paper also argues that, in the circumstances of the consultation described, it is striking that current governance deems it ethical for a practitioner to prescribe either a drug or a placebo, both of which appear to rely for their effectiveness on a measure of concealment on the part of the doctor, yet deems it unethical for a practitioner openly to prescribe a harmless and enjoyable substance which (in equivalent conditions of transparency and information) is likely to be no less effective than either drug or placebo and is also likely to be better-tolerated and cheaper than the drug.
Ordering suicide: media reporting of family assisted suicide in Britain
Authors: Banerjee Albert , Birenbaum-Carmeli Daphna
Published: October 2007

Objective:

To explore the relationship between the presentation of suffering and support for euthanasia in the British news media.

Method:

Data was retrieved by searching the British newspaper database LexisNexis from 1996 to 2000. Twenty-nine articles covering three cases of family assisted suicide (FAS) were found. Presentations of suffering were analysed employing Heidegger’s distinction between technological ordering and poetic revealing.

Findings:

With few exceptions, the press constructed the complex terrain of FAS as an orderly or orderable performance. This was enabled by containing the contradictions of FAS through a number of journalistic strategies: treating degenerative dying as an aberrant condition, smoothing over botched attempts, locating the object of ethical evaluation in persons, not contexts, abbreviating the decision making process, constructing community consensus and marginalising opposing views.

Conclusion:

The findings of this study support the view that news reporting of FAS is not neutral or inconsequential. In particular, those reports presenting FAS as an orderly, rational performance were biased in favor of technical solutions by way of the legalisation of euthanasia and/or the involvement of medical professionals. In contrast, while news reports sensitive to contradiction did not necessarily oppose euthanasia, they were less inclined to overtly support technical solutions, recognising the importance of a trial to address the complexity of FAS.
ADAPTIVE IMAGE SEGMENTATION USING ARTIFICIAL CO-EVOLVING TRIBES
Authors: CHEN YUN WEN , CHEN YAN QIU
Published: November 2007

Deriving from the artificial life theory, this paper proposes an artificial co-evolving tribes model and applies it to solve the image segmentation problem. During the evolution process, the individuals in this model making up the tribes effect communication cooperatively from one agent to the other in order to increase the homogeneity of the ensemble of the image regions they represent. Two remarkable properties, that is, the monotone contraction and the conservation of the system are proved. Stability and scale control of the proposed method are carefully analyzed. Experimental results are presented and compared with two latest segmentation methods, both quantitatively and visually. We also discuss the results matching with human visual perception.
ACTIVE EXOSKELETONS FOR UPPER-LIMB MOTION ASSIST
Authors: KIGUCHI KAZUO
Published: October 2007

This paper presents the current state of research into power-assist exoskeletons for the upper limb. The assist of the upper limb is important for physically weak persons in daily activities, since upper-limb motion is involved in many important motions in daily living. The most important criterion is that power-assist exoskeletons assist the user's motion automatically in accordance with the user's motion intentions. Electromyogram (EMG) signals in which the user's motion intention is reflected could provide vital real-time information to facilitate accurate control of the power-assist exoskeleton in accordance with the user's motion intentions. A four degree-of-freedom active exoskeleton that assists human upper-limb motion (shoulder vertical flexion/extension, shoulder horizontal flexion/extension, elbow flexion/extension, and forearm supination/pronation) is also proposed.
HUMAN AUGMENTATION AND EXOSKELETON SYSTEMS IN BERKELEY
Authors: KAZEROONI H.
Published: October 2007

Human–robot integration, in particular human augmentation, outlines the future of robotics. Although autonomous robotic systems perform remarkably in structured environments (e.g. factories), integrated human–robotic systems are superior to any autonomous robotic systems in unstructured environments that demand significant adaptation. In our research work at Berkeley, we have separated the technology associated with human power augmentation into lower extremity exoskeletons and upper extremity exoskeletons. The reason for this was two-fold: firstly, we could envision a great many applications for either a stand-alone lower or upper extremity exoskeleton in the immediate future. Secondly, and more importantly for the division is that the exoskeletons are in their early stages, and further research still needs to be conducted to ensure that the upper extremity exoskeleton and lower extremity exoskeleton can function well independently before we can venture an attempt to integrate them. With this in mind, we proceeded with the designs of the lower and upper extremity exoskeleton separately, with little concern for the development of an integrated exoskeleton. This article first gives a description of the upper extremity exoskeleton efforts and then will proceed with the more detailed description of the lower extremity exoskeleton.
SIMILARITY MEASURE OF SOFT SETS
Authors: MAJUMDAR PINAKI , SAMANTA S. K.
Published: November 2007

Soft set, as a parametrized family of subsets of a crisp universal set, has more ability to handle uncertain information. In this paper, we propose two types of similarity measure between soft sets and made a comparative study of these two techniques. Also we have shown an application of this similarity measure of soft sets.
TYROSINASE BIOSENSOR BASED ON ZINC OXIDE NANORODS
Authors: CHEN L. Y. , GU B. X. , ZHU G. P. , WU Y. F. , LIU S. Q. , XU C. X.
Published: November 2007

A phenol biosensor based on the skillful immobilization of tyrosinase on zinc oxide ( ZnO ) nanorods was proposed. The ZnO nanorods fabricated by a simple vapor-phase transport method possess a high aspect ratio, good electron communication, chemical purity, smooth and positive charged surface and are ready for immobilization of biochemicals with low isoelectric point (IEP). Electrochemical measurement and Scanning Electron Microscopic (SEM) analysis showed that the enzyme of tyrosinase with IEP 4.5 can be adsorbed on the surface of ZnO nanorods and kept its bioactivity of the oxidation of phenol to a large extent. This led us to develop phenol biosensor with good stability and reproducibility. The proposed method creates a new way to develop biosensors using nanostructured materials with high IEP.
The separation of multi-element spatial patterns in till geochemistry of southeastern Sweden combining GIS, principal component analysis and high-dimensional visualization
Authors: Grünfeld Katrin
Published: November 2007

The chemical composition of glacial till is a product of parent rocks, glacial and post-glacial processes and reflects the geogenic variation of chemical elements. Contrasting chemical composition of rock types together with spatial variation in distribution patterns of metals in the fine fraction of till in southeastern Sweden assists in the identification of the signatures reflecting parent rocks in glacial till samples. The spatial patterns of Cu, Co, Ni, Pb, V and Zn in 1411 till samples were presented by point symbol maps, followed by the extraction of multi-element associations by employing principal component analysis (PCA) and interactive high-dimensional visualization. The most influential multi-element spatial patterns in till data could be separated using either the numerical (PCA) or the visual approach. However, more information was extracted by combining the two techniques. In addition, interactive visualization provided an objective presentation of complex information in sparse lithogeochemical data. The study resulted in new knowledge about the natural variation of the levels of six elements in till, and a graphical presentation to convey information about and compare multi-element geochemical signatures.
Optimizing geochemical threshold selection while evaluating exploration techniques using a minimum hypergeometric probability method
Authors: Stanley C. R. , Noble R. R. P.
Published: November 2007

Hypergeometric statistics have recently been used to establish a quantitative measure of performance for geochemical exploration techniques over known mineral occurrences. Using this method, the effectiveness of new exploration techniques can be compared objectively with conventional approaches. Sample site classification is the basis on which survey results are compared. This performance measure requires prior knowledge of the location of mineralization and a model for element dispersion from the primary into the secondary environment. This information allows assignment of sample sites that should give ‘anomalous’ (e.g. those overlying mineralized zones) or ‘background’ results to be identified prior to the orientation survey. Previous application of hypergeometric statistics requires that a high contrast exists between ‘anomalous’ and ‘background’ subpopulations in the geochemical orientation data so that there is no uncertainty in the classification of samples. In this paper, a refinement is developed that allows consideration of geochemical variables that do not exhibit this required high level of geochemical contrast, that is, where ‘anomalous’ and ‘background’ subpopulations exhibit significant overlap. This refinement involves determining the hypergeometric probabilities of obtaining the same result at random (
P
(
x
)) for a range of geochemical thresholds, instead of only one threshold (i.e. the one used to classify anomalous and background samples in cases with high geochemical contrast). At each threshold, different numbers of samples will be classified as ‘anomalous’ and different numbers of ‘anomalous’ samples will occur at ‘anomalous’ sites. As a consequence, the resulting random hypergeometric probabilities will change with threshold level. Using a range of thresholds to classify the geochemical orientation survey results allows identification of the minimum hypergeometric probability (MHP) for the dataset. Using this threshold, the classification of anomalies will bear the least resemblance to what would be expected if the survey results were generated at random. Employing this refined MHP approach, one can simultaneously evaluate the effectiveness of an exploration method, and select the threshold that optimally classifies anomalous and background samples.
Context Learning in the Rodent Hippocampus
Authors: Fuhs Mark C. , Touretzky David S.
Published: October 2007

We present a Bayesian statistical theory of context learning in the rodent hippocampus. While context is often defined in an experimental setting in relation to specific background cues or task demands, we advance a single, more general notion of context that suffices for a variety of learning phenomena. Specifically, a context is defined as a statistically stationary distribution of experiences, and context learning is defined as the problem of how to form contexts out of groups of experiences that cluster together in time. The challenge of context learning is solving the model selection problem: How many contexts make up the rodent's world? Solving this problem requires balancing two opposing goals: minimize the variability of the distribution of experiences within a context and minimize the likelihood of transitioning between contexts. The theory provides an understanding of why hippocampal place cell remapping sometimes develops gradually over many days of experience and why even consistent landmark differences may need to be relearned after other environmental changes. The theory provides an explanation for progressive performance improvements in serial reversal learning, based on a clear dissociation between the incremental process of context learning and the relatively abrupt context selection process. The impact of partial reinforcement on reversal learning is also addressed. Finally, the theory explains why alternating sequence learning does not consistently result in unique context-dependent sequence representations in hippocampus.
Solution Methods for a New Class of Simple Model Neurons
Authors: Humphries Mark D. , Gurney Kevin
Published: October 2007

Izhikevich (2003) proposed a new canonical neuron model of spike generation. The model was surprisingly simple yet able to accurately replicate the firing patterns of different types of cortical cell. Here, we derive a solution method that allows efficient simulation of the model.