bluuebunny/crossref_metadata_2025 huggingface dataset:
MICROBEAM ANALYSIS AT TOHOKU UNIVERSITY FOR BIOLOGICAL STUDIES
Authors: MATSUYAMA S. , ISHII K. , ABE S. , OHTSU H. , YAMAZAKI H. , KIKUCHI Y. , AMARTAIVAN TS. , INOMATA K. , WATANABE Y. , ISHIZAKI A. , BARBOTTEAU Y. , SUZUKI A. , YAMAGUCHI T. , MOMOSE G. , IMASEKI H.
Published: October 2005

A microbeam analysis system at Tohoku University has been improved in detection efficiency for application to single cell analysis. The system is applicable to STIM analysis and to simultaneous PIXE and RBS analysis. Sample preparation methods suitable for non-adhesive single cell analysis were developed and first results with the improved analysis system are shown.
SYNTHESIS OF CaB6 SINGLE CRYSTALS AND SAMPLE EVALUATION BY PIXE MEASUREMENT
Authors: MIHARA M. , KUDO S. , ARIMURA K. , AKUTSU K. , NAKASHIMA Y. , FUKUDA M. , MATSUTA K. , MINAMISONO T. , INADA Y. , SHISHIDO H. , ONUKI Y.
Published: October 2005

CaB 6 single crystals were synthesized by the Al flux method and the Fe -impurity concentration in the crystal was measured using the PIXE method. As a result, we found that the amount of the Fe impurity, included in a CaB 6 powder sample used as a starting material, is drastically reduced after the synthesis process. Lightly La doped CaB 6 single crystals were also synthesized and the La concentration was determined by PIXE.
BRANE UNIVERSES AND THE COSMOLOGICAL CONSTANT
Authors: ELLWANGER ULRICH
Published: October 2005

The cosmological constant problem and brane universes are reviewed briefly. We discuss how the cosmological constant problem manifests itself in various scenarios for brane universes. We review attempts — and their difficulties — that aim at a solution of the cosmological constant problem.
Lateral Somatotopic Organization During Imagined and Prepared Movements
Authors: Michelon Pascale , Vettel Jean M. , Zacks Jeffrey M.
Published: October 2005

Motor imagery is a complex cognitive operation that requires memory retrieval, spatial attention, and possibly computations that are analogs of the physical movements being imagined. Likewise, motor preparation may or may not involve computations that are analogs of actual movements. To test whether motor imagery or motor preparation activate representations that are specific to the body part whose movement is imagined or prepared, participants performed, imagined, and prepared hand movements while undergoing functional MRI scanning. Actual hand movements activated components of the motor system including primary motor and somatosensory cortex, the supplementary motor area, the thalamus, and the cerebellum. All of these areas showed strong lateral organization, such that moving a given hand activated the contralateral cortex and ipsilateral cerebellum most strongly. During motor imagery and motor preparation, activity throughout the motor system was much reduced relative to overt movement. However, significant lateral organization was observed during both motor imagery and motor preparation in primary motor cortex, the supplementary motor area, and the thalamus. These results support the view that the subjective experience of imagined movement is accompanied by computations that are analogs of the physical movement that is imagined. They also suggest that in this regard motor imagery and motor preparation are similar.
LTP Regulates Burst Initiation and Frequency at Mossy Fiber–Granule Cell Synapses of Rat Cerebellum: Experimental Observations and Theoretical Predictions
Authors: Nieus Thierry , Sola Elisabetta , Mapelli Jonathan , Saftenku Elena , Rossi Paola , D'Angelo Egidio
Published: October 2005

Long-term potentiation (LTP) is a synaptic change supposed to provide the cellular basis for learning and memory in brain neuronal circuits. Although specific LTP expression mechanisms could be critical to determine the dynamics of repetitive neurotransmission, this important issue remained largely unexplored. In this paper, we have performed whole cell patch-clamp recordings of mossy fiber–granule cell LTP in acute rat cerebellar slices and studied its computational implications with a mathematical model. During LTP, stimulation with short impulse trains at 100 Hz revealed earlier initiation of granule cell spike bursts and a smaller nonsignificant spike frequency increase. In voltage-clamp recordings, short AMPA excitatory postsynaptic current (EPSC) trains showed short-term facilitation and depression and a sustained component probably generated by spillover. During LTP, facilitation disappeared, depression accelerated, and the sustained current increased. The N-methyl-d-aspartate (NMDA) current also increased. In agreement with a presynaptic expression caused by increased release probability, similar changes were observed by raising extracellular [Ca2+]. A mathematical model of mossy fiber–granule cell neurotransmission showed that increasing release probability efficiently modulated the first-spike delay. Glutamate spillover, by causing tonic NMDA and AMPA receptor activation, accelerated excitatory postsynaptic potential (EPSP) temporal summation and maintained a sustained spike discharge. The effect of increasing neurotransmitter release could not be replicated by increasing receptor conductance, which, like postsynaptic manipulations enhancing intrinsic excitability, proved very effective in raising granule cell output frequency. Independent regulation of spike burst initiation and frequency during LTP may provide mechanisms for temporal recoding and gain control of afferent signals at the input stage of cerebellar cortex.
Geographic variation in the frequency of scarring and tail stubs in eastern gartersnakes (Thamnophis s. sirtalis) from Michigan, USA
Authors: Burghardt Gordon , Placyk John
Published: October 2005

Tail loss, urotomy, in reptiles and amphibians has been the emphasis of many ecological and evolutionary studies, especially in lizards and salamanders; however, less is known about this phenomenon in snakes. In addition, while hypotheses for variation in tail loss across natural populations exist, none have been strongly supported. We conducted much needed research on tail loss in snakes and attempted to elucidate any relationship between variation in predator composition and frequency of wounds. 523 common gartersnakes, Thamnophis sirtalis, from 5 Michigan, USA field sites characterized by diverse predator compositions were examined for tail loss and other predator-inflicted wounds and historical records of predator composition for Michigan were updated. Our results indicate that frequency of wounds vary geographically, and that this variation may be due, in part, to differences in predator diversity. Our data also suggest that other environmental variables (e.g., predator inefficiency) that may influence the frequency of wounds in populations may be at work.
Taxonomic status of Triturus vittatus (Amphibia: Salamandridae) in western Turkey: trunk vertebrae count, genome size and allozyme data
Authors: Rosanov  , Litvinchuk  , Zuiderwijk  , Borkin
Published: October 2005

The banded newt, Triturus vittatus is suggested to consist of two species (T. ophryticus and T. vittatus). The northern taxon, T. ophryticus, is subdivided into two geographic fragments: the "western group" of populations from western Anatolian Turkey, and the "eastern group" distributed in the remaining part of the Pontic Turkey and western Caucasus. The western samples are characterized by a peculiar combination of various features. In this group the modal number of trunk vertebrae is equal to 12, like in T. v. vittatus and T. v. cilicensis, whereas the eastern group of T. ophryticus has 13 vertebrae. The amount of DNA per diploid nucleus, determined by flow cytometry, is higher in the western group (66.8-68.8 pg vs. 62.5-63.7 pg in the eastern group). Significant differences between both groups of T. ophryticus were revealed in allozymes (DNei'72 = 0.383 in average) as well. We allocate the western group of T. ophryticus to a separate subspecies, Triturus ophryticus nesterovi, subsp. nov. A paleogeographic scenario for T. vittatus and other newts is proposed. The taxonomic structure of the paraphyletic genus Triturus is discussed. We proposed to split the genus in four monophyletic genera Triturus sensu stricto, Lophinus, Mesotriton and Ommatotriton.
Indian Ocean Variability and Its Association with ENSO in a Global Coupled Model
Authors: Zhong Aihong , Hendon Harry H. , Alves Oscar
Published: October 2005

The evolution of the Indian Ocean during El Niño–Southern Oscillation is investigated in a 100-yr integration of an Australian Bureau of Meteorology coupled seasonal forecast model. During El Niño, easterly anomalies are induced across the eastern equatorial Indian Ocean. These act to suppress the equatorial thermocline to the west and elevate it to the east and initially cool (warm) the sea surface temperature (SST) in the east (west). Subsequently, the entire Indian Ocean basin warms, mainly in response to the reduced latent heat flux and enhanced shortwave radiation that is associated with suppressed rainfall. This evolution can be partially explained by the excitation of an intrinsic coupled mode that involves a feedback between anomalous equatorial easterlies and zonal gradients in SST and rainfall. This positive feedback develops in the boreal summer and autumn seasons when the mean thermocline is shallow in the eastern equatorial Indian Ocean in response to trade southeasterlies. This positive feedback diminishes once the climatological surface winds become westerly at the onset of the Australian summer monsoon.

ENSO is the leading mechanism that excites this coupled mode, but not all ENSO events are efficient at exciting it. During the typical El Niño (La Niña) event, easterly (westerly) anomalies are not induced until after boreal autumn, which is too late in the annual cycle to instigate strong dynamical coupling. Only those ENSO events that develop early (i.e., before boreal summer) instigate a strong coupled response in the Indian Ocean. The coupled mode can also be initiated in early boreal summer by an equatorward shift of the subtropical ridge in the southern Indian Ocean, which stems from uncoupled extratropical variability.
On Sampling Errors in Empirical Orthogonal Functions
Authors: Quadrelli Roberta , Bretherton Christopher S. , Wallace John M.
Published: October 2005

A perturbation analysis is carried out to quantify the eigenvector errors due to the mixing with other eigenvectors that occur when empirical orthogonal functions (EOFs) are computed for a finite-size data sample. Explicit forms are provided for the second-order eigenvalue error and first-order eigenvector error. The eigenvector sampling error depends monotonically on the ratio of the lower to the higher eigenvalues that mix. The relationship to the eigenvalue separation criterion of North et al. is discussed.

The eigenvector error formula is applied to quantify sampling errors for the leading EOF of the Northern Hemisphere wintertime geopotential height at various pressure levels, and it is found that the smallest sampling error in the troposphere occurs for the sea level pressure EOF. The errors in the 500-hPa height EOFs are almost twice as large.
The Transformation of the South African National Defence Force: A Good Beginning
Authors: Winkates James
Published: October 2005

The historic election of Nelson Mandela as president of a new Republic of South Africa in 1994 set in motion wholesale changes in the direction of the state. Among these fundamental changes is the effort to integrate six nonstatutory (former homeland and guerrilla) armies into the unified South African National Defence Force (SANDF). During these unprecedented times, the sheer numbers of national military personnel were significantly increased to integrate and enhance representation of majority black ethnic groups, while many senior white officers were pensioned off. Simultaneously, defense budget reductions greatly reduced monies available for demobilization and buyouts of military members and the desired purchase of modernized military equipment. The impact of these systemic changes, both within the republic and more widely in the southern African region, ignited serious questions on the destiny of the security forces and their future roles and missions. Definitive answers have yet to come. What we do know is that the Pretoria government no longer perceives an external security threat, but confronts internal strife stemming from opposing views on how to achieve racial reconciliation, rampant crime, high unemployment, diminished business confidence, and governmental inability to satisfy rising popular expectations. These factors, if unresolved, can threaten the progress achieved in security force restructuring, which has gone reasonably well.
Distinctive Military Attitudes among U.S. Enlistees, 1976-1997: Self-Selection versus Socialization
Authors: Bachman Jerald G. , Freedman-Doan Peter , Segal David R. , O'Malley Patrick M.
Published: October 2005

Recent reports have again raised questions about military culture and civil-military differences. This article examines panel data from the Monitoring the Future project's nationally representative samples of young men from the high school classes of 1976-1995. The study compares military recruits with their high school classmates who entered college or full-time employment, using "before-and-after" measures obtained during the senior year of high school and one or two years later. The largest disparities involved servicemen's preferences for greater military spending, and they reflected both selection (differences existing before the end of high school) and socialization (increased differences after enlistment). Servicemen were also more likely than civilian men to support greater military influence in the U.S. and were slightly more willing than their age-mates to employ U.S. military force; both reflect selection effects, with no consistent evidence of socialization. On the whole, these patterns of military attitudes have changed very little across the two decades studied.
War by Other Means: The Problem of Political Control in Irish Republican Strategy
Authors: Page Michael Von Tangen , Smith M. L. R.
Published: October 2005

This article examines the interaction between the Irish political party, Sinn Fdin, and the paramilitary group known as the Irish Republican Army (IRA). It argues that the relationship between Sinn Féin and the IRA turns the conventional Clausewitzian understanding of political control of the military on its head. Rather, in the Irish republican movement the military has had the dominant role in devising military and political strategy and Sinn Féin's role has been to support the movement's military campaign. The article traces the stresses that this relationship has had on the political development of militant Irish republicanism from its modern emergence in 1916, and then examines the consequences these have for the future of Irish republicanism and the peace process in Northern Ireland.
Strategic Culture and the Military Modernization of South Korea
Authors: Cha Victor D.
Published: October 2005

Two schools of thought in international relations theory have sought to explain the accelerated pace of arms acquisitions in Asia. The "arms" school posits that weapons purchases are a function of emerging peer competition. Countering this view, the "affluence" argument focuses on economics and status-hierarchy factors as the proximate cause for the buildup. This article tests these schools against the Republic of Korea (ROK) case, and finds both to be wrong. In spite of the economic crisis that hit Korea in 1997, the ROK's inelastic demand for military modernization confirmed that threats and strategy, not excess liquidity, drove arms acquisitions. While this finding undercuts the affluence argument, it does not confirm the predictions of the arms school. Though strategy drives Korea's pursuit of modern weapons systems, predictions of this process creating new rivalries and regional insecurity are premature. The net effect of such arms acquisitions in Asia on stability is a function not just of power and strategy, but also of these variables as refracted through the prism of culture.
Cautious Reconciliation: The Change in Societal-Military Relations in Germany and Japan Since the End of the Cold War
Authors: Arrington Aminta
Published: October 2005

The ten years since the end of the Cold War have shown that 1990 was a turning point in societal-military relationships within the countries of Germany and Japan. In this decade, the relationship between the armed forces and society changed. These countries have broken out of their Cold War molds of indifference and distance, and have found common ground. No longer occupying separate corners, the new international focus of Germany and Japan's defense policies made possible by the end of the Cold War is breathing new life into societal-military relationships, which is critical for a full normalization of these two countries.
Considering and Enjoying Tomorrow: Global Aging Through a Human Becoming Lens
Authors: Baumann Steven L. , Söderhamn Olle
Published: October 2005

The aging of the world’s population is a global issue of considerable importance to everyone, particularly nursing. Traditional developmental theories and the medical model have either neglected later life or highlighted the losses and deficits associated with advanced age, while more recent research on aging and the human becoming theory has provided a more balanced view. In this column, information from health and social sciences, the human becoming school of thought, and international political debates about aging are interwoven. Some attention is also given to the issues of the retirement and aging of the nurses.
Retinoic acid-dependent eye morphogenesis is orchestrated by neural crest cells
Authors: Matt Nicolas , Dupé Valérie , Garnier Jean-Marie , Dennefeld Christine , Chambon Pierre , Mark Manuel , Ghyselinck Norbert B.
Published: October 2005

Using genetic approaches in the mouse, we show that the primary target tissue of retinoic acid (RA) action during eye morphogenesis is not the retina nor the corneal ectoderm, which both express RA-synthesizing retinaldehyde dehydrogenases (RALDH1 and RALDH3), but the neural crest cell-derived periocular mesenchyme (POM), which is devoid of RALDH. In POM, the effects of the paracrine RA signal are mediated by the nuclear RA receptors heterodimers RXRα/RARβ and RXRα/RARγ. These heterodimers appear to control: (1) the remodeling of the POM through activation of Eya2-related apoptosis; (2) the expression of Foxc1 and Pitx2, which play crucial roles in anterior eye segment development;and (3) the growth of the ventral retina. We additionally show that RALDH1 and RALDH3 are the only enzymes that are required for RA synthesis in the eye region from E10.5 to E13.5, and that patterning of the dorsoventral axis of the retina does not require RA.
Pointed regulates an eye-specific transcriptional enhancer in theDrosophila hedgehoggene, which is required for the movement of the morphogenetic furrow
Authors: Rogers Edward M. , Brennan Catherine A. , Mortimer Nathan T. , Cook Summer , Morris Andrea R. , Moses Kevin
Published: October 2005

Drosophila development depends on stable boundaries between cellular territories, such as the embryonic parasegment boundaries and the compartment boundaries in the imaginal discs. Patterning in the compound eye is fundamentally different: the boundary is not stable, but moves (the morphogenetic furrow). Paradoxically, Hedgehog signaling is essential to both:Hedgehog is expressed in the posterior compartments in the embryo and in imaginal discs, and posterior to the morphogenetic furrow in the eye. Therefore, uniquely in the eye, cells receiving a Hedgehog signal will eventually produce the same protein. We report that the mechanism that underlies this difference is the special regulation of hedgehog(hh) transcription through the dual regulation of an eye specific enhancer. We show that this enhancer requires the Egfr/Ras pathway transcription factor Pointed. Recently, others have shown that this same enhancer also requires the eye determining transcription factor Sine oculis(So). We discuss these data in terms of a model for a combinatorial code of furrow movement.
Patient- and ward-level determinants of nursing time in nursing facilities
Authors: Laine Juha , Noro Anja , Finne-Soveri Harriet , Häkkinen Unto
Published: October 2005

Objectives: To explore the patient- and ward-level determinants of wage-adjusted nursing time in long-term care wards for the elderly with a view to improving efficiency of the use of labour resources.

Methods: The wage-adjusted nursing time given to patients was obtained from a time measurement study. Patient characteristics were based on the Minimum Data Set 2.0 of the Resident Assessment Instrument for nursing homes. Ordinary least-squares regression analysis and multilevel modelling were used to disentangle the effect of patient- and ward-level factors on nursing time.

Results: A significant difference in wage-adjusted nursing time between wards was detected, which was partly explained by characteristics of patients in wards. The combination of patients' physical functioning and cognition and the Resource Utilization Groups RUG-III/22 resource use classification explained 20–25% of patients' nursing time over a 24-hour period. Variables related to the operational environment of the ward did not explain differences in wage-adjusted nursing time once the patient profile of the ward had been controlled for. The results also showed notable unmeasured patient and ward level effects, inefficiency and randomness in the allocation of nursing time.

Conclusions: By improving the allocation and use of labour resources, the substantial variation in nursing time between wards could be diminished. Managers should allocate their staff primarily according to patients' resource needs.
What Happens When Teachers Design Educational Technology? The Development of Technological Pedagogical Content Knowledge
Authors: Koehler Matthew J. , Mishra Punya
Published: October 2005

We introduce Technological Pedagogical Content Knowledge (TPCK) as a way of representing what teachers need to know about technology, and argue for the role of authentic design-based activities in the development of this knowledge. We report data from a faculty development design seminar in which faculty members worked together with masters students to develop online courses. We developed and administered a survey that assessed the evolution of student- and faculty-participants' learning and perceptions about the learning environment, theoretical and practical knowledge of technology, course content (the design of online courses), group dynamics, and the growth of TPCK. Analyses focused on observed changes between the beginning and end of the semester. Results indicate that participants perceived that working in design teams to solve authentic problems of practice to be useful, challenging and fun. More importantly, the participants, both as individuals and as a group, appeared to have developed significantly in their knowledge of technology application, as well as in their TPCK. In brief, learning by design appears to be an effective instructional technique to develop deeper understandings of the complex web of relationships between content, pedagogy and technology and the contexts in which they function.
Drinking Motives, Alcohol Expectancies, Self-Efficacy, and Drinking Patterns
Authors: Engels Rutger C. M. E. , Wiers Reinout , Lemmers Lex , Overbeek Geertjan
Published: October 2005

The current study focused on the associations between drinking motives, alcohol expectancies, self-efficacy, and drinking behavior in a representative sample of 553 Dutch adolescents and adults. Data were gathered by means of self-report questionnaires and a 14-days drinking diary. A model was postulated in which negative expectancies and self-efficacy were directly associated with drinking, and in which drinking motives mediated the associations between positive expectancies, and drinking. The findings of multivariate analyses showed that drinking motives were related to general indicators of drinking and to drinking levels in specific situations. Furthermore, self-efficacy was moderately related to all drinking variables. Negative expectancies were related to general drinking variables but hardly to drinking in specific situations. Positive expectancies were hardly related to drinking in multivariate analyses and therefore mediation models could not be tested. No systematic moderator effects were apparent for age and gender on the associations between drinking motives, alcohol expectancies, self-efficacy, and drinking.
Why Nafta Failed and What's Needed to Protect Workers' Health and Safety in International Trade Treaties
Authors: Brown Garrett
Published: October 2005

Labor standards, including occupational health and safety regulations and enforcement, are being subjected to intense downward pressures as a result of fundamental shifts in the global economy. The 1994 North American Free Trade Agreement (NAFTA) was the first trade treaty that attempted to promote and protect workplace health and safety through a “labor side agreement.” NAFTA failed to protect workers' health and safety due to the weaknesses of the side agreement's text; the political and diplomatic considerations limiting its implementation; and the failure to recognize and address the economic context, and political consequences of this context, in which the agreement was implemented. Subsequent trade treaties, both bilateral and regional, have not overcome the weaknesses of NAFTA. The treaty components needed to protect workers' health in future trade agreements are: 1) a minimum floor of occupational health and safety regulations; 2) an “upward harmonization” of regulatory standards and actual practice; 3) inclusion of employers so that they have formal responsibility and liability for violations of the standards; 4) effective enforcement of national regulations and international standards; 5) transparency and public participation; and 6) recognition of disparate economic conditions among trading partners and provision of financial and technical assistance to overcome economic disincentives and lack of resources. Also required are continued actions by non-governmental actors, including the workers themselves and civil society organizations.
Alcohol Expectancies in Relation to Personality and Aggression among Juvenile Delinquents in Northern Russia
Authors: Koposov Roman A. , Ruchkin Vladislav V. , Eisemann Martin , Sidorov Pavel I.
Published: October 2005

The relationships between alcohol expectancies, level of alcohol use, alcohol-related problems, aggression, and personality factors in 198 Russian male juvenile delinquents were assessed. A clustering procedure was used in order to establish main patterns of alcohol expectancies, yielding three major clusters. Level of alcohol use, alcohol-related problems, aggression, and personality factors were compared across the identified clusters. It was established that juvenile delinquents with a high level of positive alcohol expectancies and aggression represented a risk-group for higher involvement in drinking behavior as well as problem drinking, which in turn are related to specific personality traits. Implications of these findings for alcohol prevention among the youth are discussed.
Technical Assistance to the Grassroots, Part II: Erin Brockovich Revisited—A Lesson for Social Policy-Making and Agency
Authors: Rosskam Ellen
Published: October 2005

Reading “Technical assistance: Providing grassroots groups access to scientific and technical information” by Barbara Berney ( New Solutions, Vol. 15, No. 1), I was overtaken by a subliminal image of Erin Brockovich (looking like Julia Roberts), who was a self-taught technical assistance provider (TA). For progressives, radicals, for those who apply participatory methods in research, for those familiar with the work of Paolo Freire and the benefits of building critical consciousness, there are some interesting extensions that can be drawn from the success stories of TAs working with grassroots groups.
Catie: A Blended Approach to Situated Professional Development
Authors: Holmes Aliya , Polhemus Linda , Jennings Sybillyn
Published: October 2005

The Capital Area Technology and Inquiry in Education program (CATIE) is a content-focused, inquiry-based professional development program developed by the Center for Initiatives in Pre-College Education (CIPCE) to assist K-6 teachers in the technology integration process. To address concerns of sustainability and cost-effectiveness, this situated model combined online and face-to-face professional development approaches to encourage thought-provoking experiences that inspire new pedagogies. CATIE united efforts with the Online Learning Forum (OLF) to offer blended mentoring experiences situated in and around the classroom context with a special focus on mathematics instruction. CATIE, formerly a high-resource model, transitioned into a multi-dimensional experience in an effort to sustain technology-rich learning communities and provide quality professional development resources for classroom instruction. This article explores the dimensions of CATIE, the transition to a blended model, and the contributions of this situated model to technology integration professional development.
Electrochemiluminescence of dipicolinic acid (DPA) and (bpy)2Ru(DPA)+ (bpy = 2,2′‐bipyridine)
Authors: Byrd Jessica , Bruno John G. , Richter Mark M.
Published: October 2005

The spectroscopic and electrochemiluminescence (ECL) properties of dipicolinic acid (DPA), (bpy)2Ru2+ (bpy = 2,2′‐bipyridine) and the species formed when DPA and (bpy)2Ru2+ [abbreviated to (bpy)2Ru(DPA)+] are allowed to react are reported. The UV‐Vis absorption maxima for (bpy)2Ru2+ and (bpy)2Ru(DPA)+ are 493 and 475 nm, respectively, indicating the in situ formation of a complex between DPA and (bpy)2Ru2+. DPA, (bpy)2Ru2+ and (bpy)2Ru(DPA)+ display ECL upon oxidation in the presence of the oxidative–reductive co‐reactant tri‐n‐propylamine (TPrA). The ECL of (bpy)2Ru(DPA)+ is at least two‐fold higher than either of the parent species. An ECL spectrum of (bpy)2Ru(DPA)+ displays a peak maximum 40 nm red‐shifted from the photoluminescence peak maximum, suggesting that the excited state formed electrochemically is different from that formed spectroscopically. Copyright © 2005 John Wiley & Sons, Ltd.
Biosynthesis and Identification of Volatiles Released by the Myxobacterium Stigmatella aurantiaca
Authors: Dickschat Jeroen S. , Bode Helge B. , Wenzel Silke C. , Müller Rolf , Schulz Stefan
Published: October 2005

The volatiles released by agar plate cultures of two strains of the myxobacterium Stigmatella aurantiaca (strains Sg a15 and DW4/3‐1) were collected in a closed‐loop stripping apparatus (CLSA) and analyzed by GC‐MS. Large numbers of substances from different compound classes (ketones, esters, lactones, terpenes, and sulfur and nitrogen compounds) were identified; several of them are reported from natural sources for the first time. The volatiles 2‐methyltridecan‐4‐one (17), its isomer 3‐methyltridecan‐4‐one (20), and the higher homologue 2‐methyltetradecan‐4‐one (18) were identified in the extracts of both strains and were synthesized. In addition, strain Sg a15 produced 2,12‐dimethyltridecan‐4‐one (19), 2‐methyltridec‐2‐en‐4‐one (23), and a series of phenyl ketones, among them 1‐phenyldecan‐1‐one (14) and 9‐methyl‐1‐phenyldecan‐1‐one (16), whereas strain DW4/3‐1 emitted traces of 10‐methylundecan‐2‐one (21). The biosynthesis of 14 and 16 was examined in feeding experiments with deuterated precursors carried out on agar plate cultures. The leucine‐derived starter unit isovalerate was shown to be incorporated into 16, as was phenylalanine‐derived benzoic acid into both 14 and 16. The results point to formation both of the phenyl ketones and of the structurally related aliphatic ketones through an unusual head‐to‐head coupling between a starter unit such as benzoyl‐CoA and a fatty acyl‐CoA, followed by decarboxylation.
As Fast and Selective as Enzymatic Ligations: Unpaired Nucleobases Increase the Selectivity of DNA‐Controlled Native Chemical PNA Ligation
Authors: Ficht Simon , Dose Christian , Seitz Oliver
Published: October 2005

DNA‐controlled reactions offer interesting opportunities in biological, chemical, and nanosciences. In practical applications, such as in DNA sequence analysis, the sequence fidelity of the chemical‐ligation reaction is of central importance. We present a ligation reaction that is as fast as and much more selective than enzymatic T4 ligase‐mediated oligonucleotide ligations. The selectivity was higher than 3000‐fold in discriminating matched from singly mismatched DNA templates. It is demonstrated that this enormous selectivity is the hallmark of the particular ligation architecture, which is distinct from previous ligation architectures designed as “nick ligations”. Interestingly, the fidelity of the native chemical ligation of peptide nucleic acids was increased by more than one order of magnitude when performing the ligation in such a way that an abasic‐site mimic was formed opposite an unpaired template base. It is shown that the high sequence fidelity of the abasic ligation could facilitate the MALDI‐TOF mass‐spectrometric analysis of early cancer onset by allowing the detection of as little as 0.2 % of single‐base mutant DNA in the presence of 99.8 % wild‐type DNA.
ζ‐Chain associated protein 70 and CD38 combined predict the time to first treatment in patients with chronic lymphocytic leukemia
Authors: Del Giudice Ilaria , Morilla Alison , Osuji Nnenna , Matutes Estella , Morilla Ricardo , Burford Anna , Maravelaki Sonia , Owusu‐Ankomah Kwasi , Swansbury John , A'Hern Roger , Brito‐Babapulle Vasantha , Catovsky Daniel
Published: October 2005

BACKGROUND

ζ‐Chain associated protein (ZAP)‐70 has been proposed as a surrogate marker for immunoglobulin heavy‐chain variable region (IgVH) mutation in chronic lymphocytic leukemia (CLL), but it is still not clear whether it is an independent prognostic factor.

METHODS

The authors evaluated ZAP‐70 expression by flow cytometry in 201 untreated patients and correlated ZAP‐70 levels with CD38 expression, genetic abnormalities detected by fluorescence in situ hybridization (FISH), and the time from diagnosis to first treatment.

RESULTS

Fifty‐seven patients (28%) were positive for ZAP‐70 (≥ 20%). Positive ZAP‐70 status was associated with advanced disease stage, atypical morphology, CD38‐positive status, trisomy 12, del(6q), or no detectable abnormalities; negative ZAP‐70 status was correlated with del(13q) as a sole abnormality. The treatment‐free interval (TFI) was 17.7 months for ZAP‐70‐positive patients and 44.6 months for ZAP‐70‐negative patients (P< 0.001). Multivariate analysis in 117 patients identified advanced stage, CD38 ≥ 7%, and the absence of del(13q) as a sole abnormality as independent factors for short TFI. Excluding FISH, ZAP‐70 status acquired independent prognostic value along with CD38 status. The authors proposed a risk model that combines ZAP‐70 and CD38 to identify patients who are likely to progress. When both markers were positive, the TFI was 12 months; when both were negative, the median TFI was 54 months; a median TFI of 26 months was observed in patients who had discordant results (P< 0.00001).

CONCLUSIONS

The current findings suggested that both ZAP‐70 and CD38 should be tested prospectively in all patients with early‐stage CLL. Cancer 2005. © 2005 American Cancer Society.
Accuracy analysis of Adini's non‐conforming plate element on anisotropic meshes
Authors: Mao Shipeng , Chen Shaochun
Published: October 2005

In this paper, we mainly study the famous Adini's non‐conforming finite element for plate‐bending problems on anisotropic meshes. Without the regular assumption on the meshes, the interpolation error and consistency error estimates are both of order O(h2) (h is the maximum diameter of elements), which improves the conventional results of this element. Lastly, a numerical test is carried out, which coincides with our theoretical analysis. Copyright © 2005 John Wiley & Sons, Ltd.
Temperature‐Dependent and Friction‐Controlled Electrochemically Induced Shuttling Along Molecular Strings Associated with Electrodes
Authors: Katz Eugenii , Baron Ronan , Willner Itamar , Richke Noa , Levine R. D.
Published: October 2005

The temperature and solvent composition dependence of the electrochemically stimulated rate of shuttling of the redox‐active cyclophane, cyclobis(paraquat‐p‐phenylene), on a molecular string has been studied. The molecular string includes a π‐donor diiminebenzene‐site that is associated on one side with an electrode, and stoppered on the other side with an adamantane unit. The cyclophane rests on the π‐donor site, owing to stabilizing π‐donor–acceptor interactions. Electrochemical reduction of the cyclophane units, to the bis‐radical cation cyclophane, results in the shuttling of the reduced cyclophane towards the electrode, a process that is driven by the removal of the stabilizing donor–acceptor interactions, and the electrostatic attraction of the reduced product by the electrode. The latter process is energetically downhill, and is temperature‐independent. Upon oxidation of the reduced cyclophane that is associated with the electrode, the energetically uphill shuttling of the oxidized cyclophane to the π‐donor site proceeds. The rate of this translocation process has been found to be temperature‐dependent, and controlled by the solvent composition. The experimental results have been theoretically analyzed in terms of Kramers’ molecular friction model. The theoretical fitting of the experimental results, using solutions of variable composition, reveals that the rate‐constants for the uphill reaction in a pure aqueous solution follow the temperature‐dependence of the viscosity of water. The results demonstrate the significance of friction phenomena in shuttling processes within molecular machines.
A Pentaporphyrin as a Switching Device Activated by Proton and Redox Stimuli
Authors: Ceroni Paola , Bergamini Giacomo , Aubert Nicolas , Troiani Vincent , Solladié Nathalie
Published: October 2005

A new pentaporphyrin array, constituted by a peptidic backbone and lateral chains with two free‐base, one MgII, and two ZnII porphyrins, has been synthesized. The electrochemical and photophysical properties are not the mere superposition of those of its model compounds: slight shifts of the E1/2 values and strong perturbation of both the Soret and Q‐band absorption show substantial ground‐state interactions among the component units, which take advantage of the rather flexible nature of the peptidic links. This multiporphyrin array, despite the flexible and nonconjugated nature of the peptidic spacers, plays the role of an antenna for visible light: an efficient photoinduced energy transfer takes place from the metalated porphyrin units to the free‐base ones. Furthermore, the light emitted by the antenna can be: 1) tuned upon protonation of the free‐base units, or 2) turned off by a redox input, since the formation of the Mg porphyrin radical cation, by either electrochemical or chemical methods, quenches the free‐base porphyrin emission. Both quenching and tuning of the emission from the light‐collecting center can be fully reverted by redox or chemical stimuli.
Boron Nanotubes
Authors: Quandt Alexander , Boustani Ihsan
Published: October 2005

A survey of novel classes of nanotubular materials based on boron is presented. Pure boron nanotubes are a consequence of a general Aufbau principle for boron clusters and solid boron phases, which postulates various novel boron materials besides the well‐known bulk phases of boron based on boron icosahedra. Furthermore, several numerical studies suggest the existence of a large family of compound nanotubular materials derived from crystalline AlB2. We compare these novel boron‐based nanotubular materials to standard nanotubular systems built from carbon, and point out a number of remarkable structural and electronic properties that make boron‐based nanotubular materials an ideal component for composite nanodevices and extended nanotubular networks.
Shuttling Dynamics in an Acid–Base‐Switchable [2]Rotaxane
Authors: Garaudée Sandrine , Silvi Serena , Venturi Margherita , Credi Alberto , Flood Amar H. , Stoddart J. Fraser
Published: October 2005

Molecular shuttles are an intriguing class of rotaxanes which constitute prototypes of mechanical molecular machines and motors. By using stopped‐flow spectroscopic techniques in acetonitrile solution, we investigated the kinetics of the shuttling process of a dibenzo[24]crown‐8 ether (DB24C8) macrocycle between two recognition sites or “stations”—a secondary ammonium (NH2+)/amine (NH) center and a 4,4′‐bipyridinium (bipy2+) unit—located on the dumbbell component in a [2]rotaxane. The affinity for DB24C8 decreases in the order NH2+>bipy2+>NH. Hence, shuttling of the DB24C8 macrocycle can be obtained by deprotonation and reprotonation of the ammonium station, reactions which are easily accomplished by addition of base and acid to the solution. The rate constants were measured as a function of temperature in the range 277–303 K, and activation parameters for the shuttling motion in both directions were determined. The effect of different counterions on the shuttling rates was examined. The shuttling from the NH2+ to the bipy2+ station, induced by the deprotonation of the ammonium site, is considerably slower than the shuttling in the reverse direction, which is, in turn, activated by reprotonation of the amine site. The results show that the dynamics of the shuttling processes are related to the change in the intercomponent interactions and structural features of the two mutually interlocked molecular components. Our observations also indicate that the counterions of the cationic rotaxane constitute an important contribution to the activation barrier for shuttling.
Detection of soluble human granzyme K in vitro and in vivo
Authors: Bade Britta , Lohrmann Jens , ten Brinke Anja , Wolbink Angela M. , Wolbink Gert‐Jan , Berge Ineke J. M. ten , Virchow J. Christian , Luttmann Werner , Hack C. Erik
Published: October 2005

Granzymes are serine proteases released from the granules of cytotoxic lymphocytes during the induction of apoptosis. To evaluate the physiologic role of human granzyme K (GzmK), we developed a sensitive ELISA which was shown to specifically detect human GzmK in its active as well as its inactive conformation. Analysis of the lysate of lymphokine‐activated killer (LAK) cells by gel filtration revealed that GzmK seems to be complexed to proteoglycans within these cells. While the expression of GzmA and B by cytotoxic lymphocytes was strongly up‐regulated in response to several activating stimuli, GzmK expression did not increase significantly above constitutive levels, indicating differential regulation of these granzymes. However, low levels of GzmK were detected in plasma samples of healthy volunteers, which were in the same range as levels of GzmA and B. Furthermore, circulating levels of GzmK as well as of GzmA and B were significantly elevated in patients suffering from viral infections. We conclude that GzmK protein is produced by cytotoxic cells, and just as GzmA and B it can be released in a soluble form into the extracellular space. Furthermore, our data suggest that despite a more restricted cellular expression pattern, GzmK seems to participate in immune responses against several viruses.
Expression of complement factor H binding immunoevasion proteins in Borrelia garinii isolated from patients with neuroborreliosis
Authors: Alitalo Antti , Meri Taru , Comstedt Pär , Jeffery Luke , Tornberg Johanna , Strandin Tomas , Lankinen Hilkka , Bergström Sven , Cinco Marina , Vuppala Santosh R. , Akins Darrin R. , Meri Seppo
Published: October 2005

The Lyme disease‐pathogen Borrelia burgdorferi binds the complement inhibitor factor H (FH) to its outer surface protein E‐ (OspE) and BbA68‐families of lipoproteins. In earlier studies, only serum‐resistant strains of the genospecies B. burgdorferi sensu stricto or B. afzelii, but not serum‐sensitive B. garinii strains, have been shown to bind FH. Since B. garinii often causes neuroborreliosis in man, we have readdressed the interactions of B. garinii with FH. B. garinii 50/97 strain did not express FH‐binding proteins. By transforming the B. garinii 50/97 strain with an OspE‐encoding gene from complement‐resistant B. burgdorferi (ospE‐297), its resistance to serum killing could be increased. OspE genes were detected and cloned from the B. garinii BITS, Pistoia and 40/97 strains by PCR and sequencing. The deduced amino acid sequences differed in an N‐terminal lysine‐rich FH‐binding region from OspE sequences of resistant strains. Recombinant B. garinii BITS OspE protein was found to have a considerably lower FH‐binding activity than the B. burgdorferi sensu stricto 297 OspE protein P21 (P21–297). Unlike bacteria that had been kept in culture for a long time, neurovirulent B. garinii strains from neuroborreliosis patients were found to express ∼27‐kDa FH‐binding proteins. These were not recognized by polyclonal anti‐OspE or anti‐BbA68 antibodies. We conclude that B. garinii strains carry ospE genes but have a decreased expression of OspE proteins and a reduced ability to bind FH, especially when grown for prolonged periods in vitro. Recently isolated neuroinvasive B. garinii strains, however, can express FH‐binding proteins, which may contribute to the virulence of neuroborreliosis‐causing B. garinii strains.
Three‐dimensional eddy current calculation in multiply connected regions by using the magnetic vector potential
Authors: Morisue Toshiya
Published: October 2005

There are two methods of using the magnetic vector potential for three‐dimensional eddy current calculations. The first method uses the continuous magnetic vector potential which accompanies a scalar potential and has the advantage that no cutting is necessary for the multiply connected region problem. The second method uses the discontinuous magnetic vector potential which accompanies no scalar potential and has the disadvantage that cutting is necessary for the multiply connected region problem. In this paper a formulation using the continuous magnetic vector potential and accompanying scalar potential is given, together with computed results for three three‐dimensional multiply connected eddy current problems.
Numerical analysis of convection‐diffusion with chemical reaction by combined finite and boundary element methods
Authors: Okamoto Naotaka , Kawahara Mutsuto
Published: October 2005

A numerical method is presented to analyse a steady convection‐diffusion problem with a first‐order chemical reaction defined on an infinite region. The present method is based on the combined finite element and boundary element methods. For one‐ and two‐dimensional examples in an infinite region the numerical results by the present method are in excellent agreement with the exact solutions. As a practical application, the simulation of the concentration distribution of the chemical oxygen demand at Kojima Bay is carried out.
Application of Taylor‐least squares finite element to three‐dimensional advection‐diffusion equation
Authors: Park N.‐S. , Liggett J. A.
Published: October 2005

The Taylor‐least squares (TLS) scheme, developed to solve the unsteady advection‐diffusion equation for advection‐dominated cases in one and two dimensions, is extended to three dimensions and applied to some 3D examples to demonstrate its accuracy. The serendipity Hermite element is selected as an interpolation function on a linear hexagonal element. As a validation of the code and as a simple sensitivity analysis of the scheme on the different types of shape functions, the 2D example problem of the previous study is solved again. Four 3D problems, two with advection and two with advection‐diffusion, are also solved. The first two examples are advection of a steep 3D Gaussian hill in rotational flow fields. For the advection‐diffusion problems with fairly general flow fields and diffusion tensors, analytical solutions are obtained using the ray method. Despite the steepness of the initial conditions, very good agreement is observed between the analytical and TLS solutions.