bluuebunny/crossref_metadata_2025 huggingface dataset:
Fluorescence Quenching Study on the Interaction of Some Schiff Base Complexes with Bovine Serum Albumin
Authors: MEI Ping , ZHANG Li‐Xi , LIU Yi , CAI Li‐Hua , HU Pei‐Zhi
Published: January 2008

The interaction of Schiff base ligand A and its three metal complexes [A‐Fe(II), A‐Cu(II), and A‐Zn(II)] with bovine serum albumin (BSA) was investigated using a tryptophan fluorescence quenching method. The Schiff base ligand A and its three metal complexes all showed quenching of BSA fluorescence in a Tris‐HCl buffer. Quenching constants were determined for quenching BSA by the Schiff base ligand A and its metal complexes in a Tris‐HCl buffer (pH=7.4) at different temperatures. The experimental results show that the dynamic quenching constant (KSV) was increased with increasing temperature, whereas the association constant (K) was decreased with the increase of temperature. The thermodynamic parameters ΔH, ΔG and ΔS at different temperatures were calculated. The ionic strength of the Tris‐HCl buffer had a great influence on the wavelength of maximum emission of BSA. Under low ionic strength, the emission spectra of BSA influenced by A‐Zn(II) had a small blue shift. Compared to A‐Zn(II), the emission spectra of BSA in the presence of the Schiff base ligand A and A‐Cu(II) had no significant λem shift. At high ionic strength, the emission spectra of BSA upon addition of the Schiff base A, A‐Fe(II), and A‐Zn(II) all had a red shift, but the emission spectra of BSA had λem shift neither at low ionic strength, nor at high ionic strength in the presence of A‐Cu(II). Furthermore, the temperature did not affect the λem shift of BSA emission spectra.
Aromaticity of All Possible C26N2 Isomers
Authors: TANG Ming‐Hui , ABLIKIM Kerim
Published: January 2008

The aromaticity of all possible heterofullerenes C26N2 and C28 based on Td symmetry has been studied by means of the topological resonance energy and percentage topological resonance energy methods. The relationship between the aromaticity of the C26N2 isomers and the sites where nitrogen atoms dope at the C28 cage has been discussed. The calculation results show that the most stable isomer of C26N2 derivatives is formed by nitrogen atoms doping at the two tetrahedral vertices. C26N2 isomers are more stable than C28, but the C26N22− isomers are less stable than C28 4−4. The effect of nitrogen substitution on C28 stability was investigated by the topological charge stabilization rule.
Fluorescence Nanoscopy with Optical Sectioning by Two‐Photon Induced Molecular Switching using Continuous‐Wave Lasers
Authors: Fölling Jonas , Belov Vladimir , Riedel D. , Schönle Andreas , Egner Alexander , Eggeling Christian , Bossi Mariano , Hell Stefan W.
Published: January 2008

During the last decade far‐field fluorescence microscopy methods have evolved that have resolution far below the wavelength of light. To outperform the limiting role of diffraction, all these methods, in one way or another, switch the ability of a molecule to emit fluorescence. Here we present a novel rhodamine amide that can be photoswitched from a nonfluorescent to a fluorescent state by absorption of one or two photons from a continuous‐wave laser beam. This bright marker enables strict control of on/off switching and provides single‐molecule localization precision down to 15 nm in the focal plane. Two‐photon induced nonlinear photoswitching of this marker with continuous‐wave illumination offers optical sectioning with simple laser equipment. Future synthesis of similar compounds holds great promise for cost‐effective fluorescence nanoscopy with noninvasive optical sectioning.
Osteopontin is produced by mast cells and affects IgE‐mediated degranulation and migration of mast cells
Authors: Nagasaka Akiko , Matsue Hiroyuki , Matsushima Hironori , Aoki Rui , Nakamura Yuumi , Kambe Naotomo , Kon Shigeyuki , Uede Toshimitsu , Shimada Shinji
Published: January 2008

Osteopontin (OPN), originally discovered in bone as an extracellular matrix protein, was identified in many cell types in the immune system, presumably being involved in many aspects of pathogenesis of inflammatory and immune diseases. Mast cells are also involved in such pathological aspects by secreting multiple mediators. However, it has not been determined whether mast cells produce OPN and whether it affects their function. To test this, we used murine fetal skin‐derived cultured mast cells (FSMC) and bone marrow‐derived cultured mast cells. We found that OPN was spontaneously produced by FSMC and inducible by ionomycin and FcϵRI aggregation in bone marrow‐derived cultured mast cells. In the presence of mast cell growth factors, FSMC were similarly generated from both OPN‐deficient (OPN–/–) and ‐sufficient (OPN+/+) mice without significant differences in yield, purity, granularity, and viability. Using OPN–/– FSMC, we found that recombinant OPN augmented IgE‐mediated degranulation and induced FSMC chemotaxis. Both effects were mediated by OPN receptors (i.e. CD44 and integrin αv). IgE‐mediated passive cutaneous anaphylaxis was significantly reduced in OPN–/– mice compared with OPN+/+ mice, indicating physiological relevance of OPN. These results indicate that OPN is a mast cell mediator, enhances mast cell responses to antigen, and thus may influence mast cell‐related pathological conditions.

See accompanying commentary at http://dx.doi.org/10.1002/eji200738131
IL‐10 suppressor activity and ex vivo Tr1 cell function are impaired in multiple sclerosis
Authors: Martinez‐Forero Ivan , Garcia‐Munoz Ricardo , Martinez‐Pasamar Sara , Inoges Susana , Lopez‐Diaz de Cerio Ascensión , Palacios Ricardo , Sepulcre Jorge , Moreno Beatriz , Gonzalez Zaira , Fernandez‐Diez Begoña , Melero Ignacio , Bendandi Maurizio , Villoslada Pablo
Published: January 2008

T regulatory cells type 1 (Tr1 cells) are excellent candidates for cell therapy in multiple sclerosis (MS). The aim of our study was to assess the functional state of Tr1 cells and IL‐10R signaling in patients with MS. Tr1 cells were induced in vitro by activation with anti‐CD46 antibodies in controls and patients with MS. Cells were phenotyped by cytometry and suppression assays, and the expression of cytokines and transcription factors was evaluated by real‐time PCR, ELISA, cytometry and Western blotting. We found that the activity of Tr1 cells and IL‐10R signaling is impaired in MS patients since Tr1 cells isolated from MS patients produced less IL‐10 than those obtained from controls. Indeed, the supernatants from Tr1 cells from controls did not suppress the proliferation of stimulated CD4+ cells from patients with MS. Furthermore, the IL‐10R signaling pathway was not fully active in CD4+ cells from MS patients and these cells had higher baseline levels of SOCS3 transcripts than controls. Indeed, after in vitro IL‐10 stimulation, the expression levels of the STAT1, STAT3 and IL‐10RA genes were higher in MS patients than in controls. Moreover, Stat‐3 phosphorylation was lower in controls than in patients after IL‐10 stimulation. These results indicate that IL‐10 regulatory function is impaired in patients with MS.
Engineering tissue tubes using novel multilayered scaffolds in the rat peritoneal cavity
Authors: Cao Yang , Zhang Bing , Croll Tristan , Rolfe Barbara E. , Campbell Julie H. , Campbell Gordon R. , Martin Darren , Cooper‐White Justin J.
Published: January 2008

Our aim was to develop novel scaffolds to engineer tissue tubes of smooth muscle‐like cells for autologous grafting. Small diameter tubular poly(lactic acid) scaffolds with randomly distributed, interconnected pores up to 100 μm were produced using a thermally induced phase separation method. The scaffolds were surface modified using various biomolecules via a layer‐by‐layer deposition technique, and implanted in the peritoneal cavities of rats. Histological analysis of scaffolds 3 weeks after implantation showed fully‐developed tissue capsules on their outer surfaces, with macrophage‐like cells present throughout the internal spaces. Surfaces coated in Matrigel supported the strongest cellular response whereas multilayer coatings with elastin, collagen I, collagen III, or chitosan outermost showed the lowest levels of cellular interaction. Although differences in capsule thickness and the presence or absence of cellularized layers on the inside and outside surfaces of the scaffolds were observed, none of these biomolecule coatings was able to overcome the foreign body response within the peritoneal cavity, even in the presence of a nonadsorptive HA undercoat. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
In vitro and in vivo characterization of porous poly‐L‐lactic acid coatings for subcutaneously implanted glucose sensors
Authors: Koschwanez H. E. , Yap F. Y. , Klitzman B. , Reichert W. M.
Published: January 2008

The purpose of this study was to test the hypothesis that porous poly‐L‐lactic acid (PLLA) sensor coatings reduce fibrosis and promote blood microvessel formation in tissue adjacent to the sensor surface. Porous PLLA coatings were produced using ammonium bicarbonate as the gas foaming/salt leaching agent, and deployed on functional and nonfunctional sensors. The porous coatings minimally affected sensor accuracy and response rate in vitro. Three‐week subcutaneous rat studies of nonfunctional glucose sensors showed the anticipated effect of porous coatings enhancing vascularity and decreasing collagen deposition. In contrast, percutaneous functional sensors with and without porous coatings showed no significant difference in terms of histology or sensor response. In spite of the observation that texturing increases the vascularity of the tissue that surrounds implanted sensors, other factors such as the additional mechanical stresses imposed by percutaneous tethering may override the beneficial effects of the porous coatings. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Magnetotransport of electrons in quantum Hall systems
Authors: Dmitriev I. A. , Evers F. , Gornyi I. V. , Mirlin A. D. , Polyakov D. G. , Wölfle P.
Published: January 2008

Recent theoretical results on magnetotransport of electrons in a 2D system in the range of moderately strong transverse magnetic fields are reviewed. The phenomena discussed include: quasiclassical memory effects in systems with various types of disorder, transport in lateral superlattices, interaction‐induced quantum magnetoresistance, quantum magnetooscillations in dc and ac transport, and oscillatory microwave photoconductivity. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Myelomeningocele: neglected aspects
Authors: Woodhouse Christopher R. J.
Published: January 2008

The commonest cause of neurogenic bladder in children is myelomeningocele. Survival of children is much improved in the Western world, but by 35 years old, about 50% will have died. In adults, the commonest causes of death are lung and heart diseases. All physical aspects deteriorate with age, especially in those with thoracic lesions. Those who walk in childhood have a 20–50% chance of becoming wheelchair dependent as adults. Immobility, poor respiratory reserve, obesity, latex allergy and worsening kyphoscoliosis contribute to the increased risks of surgery. It is essential that safe and manageable urine drainage is established in childhood: the bladder never improves with time, and surgical reconstruction becomes progressively more difficult. Independence in adult life will only be possible with intense preparation in childhood. Children must be allowed to join in with family chores and events. Education, both academic and practical, must be encouraged. Skills such as driving, shopping and birth control must be taught. However, even with the best support, less than 40% will have gainful employment. Children who are continent and have lesions below L2 are likely to have normal sexual function. Sexual activity in adolescents, especially in those with hydrocephalus, is limited (but not absent). However, by adult life, about two thirds will have established a regular partnership. All females and those males who are naturally potent are likely to be fertile. There is a high risk of neural tube defects in their offspring unless the female partner takes prophylactic folic acid for 3 months before pregnancy and for first trimester.
The Surprising Results of the Saudi Arabian 2004 Demographic Census
Authors: WINCKLER ONN
Published: January 2008

At first glance, in contrast to political documents, official demographic data, particularly total population figures, “look innocent.” The common tendency is to accept them “as is” because governments tend not to manipulate the declared number of their citizens. In most cases this assumption is true. Is it also true for Saudi Arabia? In the 1970s and 1990s, Saudi authorities published the results of two demographic censuses that numbered the Saudi citizenry at 6,218,361 in September 1974 and 12,310,053 in September 1992. However, many experts found these figures to be highly inflated, as shown in the table.
NOTORIOUS SUBJECTS, INVISIBLE CITIZENS: NORTH CAUCASIAN RESISTANCE TO THE TURKISH NATIONAL MOVEMENT IN NORTHWESTERN ANATOLIA, 1919–23
Authors: Gingeras Ryan
Published: January 2008

For contemporary Istanbulites, a trip south, across the Sea of Marmara, poses nothing exceptional or treacherous. The southern shore is often a day-trip destination for those seeking to relax or sightsee in the port towns of Yalova or Çanakkale. The Marmara's southern coast is also a stop on the road to warmer, more comfortable climes farther south, such as the holiday resorts of Kuşadası or Foça. The region stands in sharp contrast to the farthest reaches of eastern Anatolia, such as Van, Diyarbakir, or Mardin, where an insurgency by Kurdish guerrillas continues to claim lives.
PREDICTORS OF AGE AT MENARCHE IN THE NEWCASTLE THOUSAND FAMILIES STUDY
Authors: BLELL MWENZA , POLLARD TESSA M. , PEARCE MARK S.
Published: January 2008

Several studies have found relationships between early life factors (birth weight, length of gestation, height, weight, duration of breast-feeding, maternal age, social class, periods of infection, presence of adverse life events, and quality of housing conditions in childhood) and age at menarche but none has considered all of these factors in the same study. The follow-up study of the Newcastle Thousand Families birth cohort, established in 1947, provided age at menarche data collected retrospectively at age 50 from 276 women who returned self-completion questionnaires in 1997. Three main independent associations were observed: girls who experienced a shorter gestation, girls whose mothers were younger when they were born, and girls who were heavier at age 9 had earlier menarche. Birth weight, standardized for gestational age, was found to have different relationships with age at menarche depending upon how heavy or light a girl was at age 9. The results of this study support the hypotheses that conditions in fetal and early life are associated with the timing of menarche and that greater childhood growth is associated with earlier menarche. It is suggested that future work should focus on illuminating the mechanisms underlying these statistical relationships.
The effect of heterogeneous infectious period and contagiousness on the dynamics ofSalmonellatransmission in dairy cattle
Authors: LANZAS C. , BRIEN S. , IVANEK R. , LO Y. , CHAPAGAIN P. P. , RAY K. A. , AYSCUE P. , WARNICK L. D. , GRÖHN Y. T.
Published: January 2008

The objective of this study was to address the impact of heterogeneity of infectious period and contagiousness onSalmonellatransmission dynamics in dairy cattle populations. We developed three deterministic SIR-type models with two basic infected stages (clinically and subclinically infected). In addition, model 2 included long-term shedders, which were defined as individuals with low contagiousness but long infectious period, and model 3 included super-shedders (individuals with high contagiousness and long infectious period). The simulated dynamics, basic reproduction number (R0) and critical vaccination threshold were studied. Clinically infected individuals were the main force of infection transmission for models 1 and 2. Long-term shedders had a small impact on the transmission of the infection and on the estimated vaccination thresholds. The presence of super-shedders increasesR0and decreases the effectiveness of population-wise strategies to reduce infection, making necessary the application of strategies that target this specific group.
Use of Porous Alginate Sponges for Substantial Chondrocyte Expansion and Matrix Production: Effects of Seeding Density
Authors: Yen Chi‐Nan , Lin Yu‐Ru , Chang Margaret Dah‐Tsyr , Tien Chun‐Wen , Wu Yu‐Chih , Liao Chun‐Jen , Hu Yu‐Chen
Published: January 2008

Autologous cell transplantation is a promising approach for cartilage repair, but the expansion of chondrocytes in a monolayer, a common approach to amplifying the cell number, inevitably leads to cell de‐differentiation. To explore whether porous alginate sponges could be utilized for chondrocyte expansion and investigate the effects of seeding densities, the porcine chondrocytes were seeded to porous alginate sponges at low (5 × 105 cells per 40 sponges), medium (5 × 106 cells per 40 sponges), or high (2 × 107 cells per 40 sponges) density. After 4‐week perfusion culture, all three groups resulted in chondrocyte proliferation, maintenance of chondrocytic gene (collagen II, Sox 9 and aggrecan) expression, and formation of cell clusters resembling cartilaginous tissues. The higher the seeding density, the higher the final cell density and GAGs production and, accordingly, the larger the cell clusters. Strikingly, the cumulative expansion ratios achieved by the low‐density group (∼150‐fold) significantly exceeded those achieved by the medium (∼21‐fold) and high (∼4.7‐fold) density groups, as well as those achieved using other scaffolds. In conclusion, seeding chondrocytes to the alginate sponges at a low density, combined with perfusion culture, represents a drastic improvement in expanding autologous chondrocytes.
Im Spiegel der Zeitschrift: Themen und Trends der Pädagogischen Psychologie in den Jahren 2005 bis 2007
Authors: Leutner Detlev , Wirth Joachim
Published: January 2008

Zusammenfassung. Zu Beginn des Jahres 2008 wechselt die geschäftsführende Herausgeberschaft der Zeitschrift für Pädagogische Psychologie von Detlev Leutner zu Jens Möller. Aus diesem Anlass werden Zahlen, Fakten und Trends der sich in den Artikeln der Zeitschrift spiegelnden Pädagogischen Psychologie der letzten Jahre zusammenfassend untersucht. Es zeigt sich, dass sich die Zeitschrift unter den Autorinnen und Autoren zunehmender Beliebtheit erfreut, was zu einer gestiegenen Zahl eingereichter Manuskripte und einer erhöhten Ablehnungsquote geführt hat. Eine Analyse des Journal-Impact-Faktors der Zeitschrift ergibt, dass die Variabilität des Impact-Faktors ausschließlich auf die Variabilität der Selbstzitationen (d. h. Zitation von Artikeln der Zeitschrift durch die eigene Zeitschrift) zurückzuführen ist, während die Fremdzitationen (d. h. Zitation von Artikeln der Zeitschrift durch andere Zeitschriften) über die Jahre hinweg weitgehend stabil sind und einen für deutschsprachige Zeitschriften beachtlichen Anteil des Impact-Faktors in Höhe von konstant ca. 0.50 Impact-Punkten ausmachen. Hinsichtlich thematischer Trends zeigt sich eine über die Jahre hinweg deutliche Zunahme an Artikeln im Bereich “Selbstkonzept, Motivation und Emotion im Lernprozess” zu Lasten von Artikeln in den Bereichen “Lernen und Lehren” und “Pädagogisch-psychologische Trainingsforschung”. Insgesamt scheint die Zeitschrift für Pädagogische Psychologie für die kommenden Jahre gut aufgestellt zu sein.
Guest Editorial for the Special Section: Motivation Affects Performance. But Which Aspect of Motivation?
Authors: Vollmeyer Regina
Published: January 2008

Abstract: Using expectancy-value models, specifically Heckhausen and Rheinberg's (1980) Expanded Motivation Model, as a framework, the individual paper contributions to the special issue are introduced, focusing on the motivational constructs addressed in the papers.
Lernen bei attraktiven Handlungsalternativen
Authors: Fries Stefan , Schmid Sebastian
Published: January 2008

Zusammenfassung. Schüler bearbeiten Lernaufgaben häufig in Situationen, in denen ihnen gleichzeitig attraktive Freizeitalternativen zur Verfügung stehen. In einem Experiment wurde die Vermutung untersucht, dass solche Handlungsalternativen sich negativ auf das Erleben und die Performanz beim Lernen auswirken. Schüler (N = 57; mittleres Alter: 16.1) fertigten Beschreibungen naturwissenschaftlicher Abbildungen in drei experimentellen Gruppen an. Während die Schüler in der Kontrollgruppe ohne attraktive Handlungsalternative arbeiteten, konnten die Schüler in den beiden anderen Experimentalgruppen zu beliebigen Zeitpunkten die Beschreibungsaufgabe unterbrechen, um Musikvideos anzuschauen. Zudem wurde variiert, ob das Anschauen der Musikvideos als erlaubt galt. Die Schüler aus den beiden Gruppen mit Musikvideos berichteten ein höheres Interferenzerleben, produzierten qualitativ schlechtere Abbildungsbeschreibungen und wussten anschließend weniger über die Abbildungsinhalte. Ob das Anschauen der Musikvideos erlaubt war oder nicht, hatte dagegen keinen Einfluss auf die abhängigen Variablen. Die Untersuchung verdeutlicht, dass attraktive Handlungsalternativen das Lernen negativ beeinflussen können.
Sea ice remote sensing using AMSR‐E 89‐GHz channels
Authors: Spreen G. , Kaleschke L. , Heygster G.
Published: January 2008

Recent progress in sea ice concentration remote sensing by satellite microwave radiometers has been stimulated by two developments: First, the new sensor Advanced Microwave Scanning Radiometer‐EOS (AMSR‐E) offers spatial resolutions of approximately 6 × 4 km at 89 GHz, nearly 3 times the resolution of the standard sensor SSM/I at 85 GHz (15 × 13 km). Second, a new algorithm enables estimation of sea ice concentration from the channels near 90 GHz, despite the enhanced atmospheric influence in these channels. This allows full exploitation of their horizontal resolution, which is up to 4 times finer than that of the channels near 19 and 37 GHz, the frequencies used by the most widespread algorithms for sea ice retrieval, the NASA‐Team and Bootstrap algorithms. The ASI algorithm used combines a model for retrieving the sea ice concentration from SSM/I 85‐GHz data proposed by Svendsen et al. (1987) with an ocean mask derived from the 18‐, 23‐, and 37‐GHz AMSR‐E data using weather filters. During two ship campaigns, the correlation of ASI, NASA‐Team 2, and Bootstrap algorithms ice concentrations with bridge observations were 0.80, 0.79, and 0.81, respectively. Systematic differences over the complete AMSR‐E period (2002–2006) between ASI and NASA‐Team 2 are below −2 ± 8.8%, and between ASI and Bootstrap are 1.7 ± 10.8%. Among the geophysical implications of the ASI algorithm are: (1) Its higher spatial resolution allows better estimation of crucial variables in numerical atmospheric and ocean models, for example, the heat flux between ocean and atmosphere, especially near coastlines and in polynyas. (2) It provides an additional time series of ice area and extent for climate studies.
Unusually long lasting multiple penetration of interplanetary electric field to equatorial ionosphere under oscillating IMF Bz
Authors: Wei Yong , Hong Minghua , Wan Weixing , Du Aimin , Lei Jiuhou , Zhao Biqiang , Wang Wenbin , Ren Zhipeng , Yue Xinan
Published: January 2008

During November 11–16, 2003, the interplanetary magnetic field (IMF) Bz oscillated between northward and southward directions, which suggests discontinuous magnetic reconnection associated with the multiple pulses‐like reconnection electric field. The Jicamarca incoherent scatter radar (ISR) measurements of ionospheric zonal electric field showed similar fluctuations during this period. The high correlation coefficient of 0.71 between the reconnection electric field and equatorial zonal electric field during 125 hours suggests that the interplanetary electric field (IEF) pulsively penetrated into the equatorial ionosphere due to the discontinuous magnetic reconnection. It is implied that the short lifetime (<3 hours) dawn‐dusk IEF pulses can penetrate into ionosphere without shielding, in other words, they may exhibit the “shielding immunity”. The averaged penetration efficiency is about 0.136 and highly local time‐dependent. Furthermore, the intense AU and AL indices imply that the multiple electric field penetration is associated with a “High‐Intensity Long‐Duration Continuous AE Activity (HILDCAA).”
A seasonal study of mesospheric temperatures and emission intensities at Adelaide and Alice Springs
Authors: Gelinas L. J. , Hecht J. H. , Walterscheid R. L. , Roble R. G. , Woithe J. M.
Published: January 2008

Aerospace imagers operating at Alice Springs (23°42′S, 133°53′E) and Adelaide (34°55′S, 138°36′E) have collected more than 4‐year of OH and O2 atmospheric emission data. Images taken over the course of each moonless night at 5‐min intervals were used to determine OH Meinel (6, 2) and O2 Atmospheric (0, 1) band emission intensities and temperatures, as well as atmospheric gravity wave parameters. The NCAR general circulation model TIME‐GCM was run for years 2002–2005 for comparison with these data. The data presented here show the interannual variability of OH and O2A emissions at two sites, Alice Springs and Adelaide, over a 4‐a period. It was found that the TIME‐GCM successfully reproduces many observed features of the data, including equinoctial maxima associated with the diurnal tide, a 6‐h phase shift between OH temperature and intensity maxima, and springtime OH intensity enhancements at Alice Springs. However, the model tends to underestimate the depth of the summertime temperature minimum at both sites, possibly due to inadequate specification of the seasonal variation of gravity waves in the model. The model does, however, successfully describe many of the mesospheric changes observed during the 2002 stratospheric warming event.
Regional structure and kinematic history of a large subduction back thrust: Taranaki Fault, New Zealand
Authors: Stagpoole V. , Nicol A.
Published: January 2008

The Taranaki Fault is a back thrust antithetic to the Hikurangi margin subduction thrust. Subduction back thrusts, like the Taranaki Fault, accrue displacement transferred from the subducting plate, and growth analyses of these structures contribute to an improved understanding of subduction processes. The Taranaki Fault forms the eastern margin of the Taranaki Basin and is part of a system that extends for at least 600 km in continental crust of western New Zealand. The fault is preserved beneath young sedimentary cover and provides a rare opportunity to investigate the geometry and kinematic history of a large subduction back thrust. Two‐dimensional seismic reflection lines (2–5 km spacing), tied to recently drilled wells and outcrop, together with magnetotelluric and gravity models are used to examine the fault. These data indicate that the fault is thick skinned with dips of 25–45° to depths of at least 12 km. The fault accommodated at least 12–15 km of dip‐slip displacement since the middle Eocene (circa 40–43 Ma). The northern tip of the active section of the fault stepped southward at least three times between the middle Eocene and early Pliocene, producing a total tip retreat of 400–450 km. The history of displacements on the Taranaki Fault is consistent with initiation of Hikurangi margin subduction during the middle Eocene, up to 20 Ma earlier than some previous estimates. Fault tip retreat may have been generated by clockwise rotation of the subduction margin and associated progressive isolation of the fault from the driving downgoing Pacific Plate.
The Ghost in the City and a Landscape of Life: A Reading of Difference in Shirow and Oshii's Ghost in the Shell
Authors: Curti Giorgio Hadi
Published: January 2008

In this paper I demonstrate how an ontological perspective variously informed by Spinozan and Deleuzian philosophy and the (Shinto-influenced) work of Japanese artists Masamune Shirow and Mamoru Oshii offers an approach to landscape which decenters human position(s) and allows an exploration of landscape on its own terms. Through an empirical exploration of this approach, I analyze the animated Japanese science fiction film Ghost in the Shell (1998 [1995]), and discuss how its imagery, ideas, and philosophies can elucidate and aid in an understanding of landscape, not as a separate or passive entity but as a relational living and endeavoring thing.
Acute Limbic Encephalitis: Diagnostic and Management Implications
Authors: Lucas-Ramadan Tracey , Baxi Shrujal , Velamoor Raj
Published: January 2008

Objective: A link between cancer and limbic encephalitis (LE) has been proposed. The aim of this case presentation is to further explore this association by literature review, inform clinicians of the investigations necessary to arrive at a diagnosis and to emphasize the clinical importance of liaison between psychiatry and other disciplines involved in management.

Method: The case report of a 55 year old Niuean male school teacher with an acute onset of confusion and personality change is presented. The clinical data was obtained from various sources including the emergency room, medical ward, psychiatric ward as well as from discussions with other physicians involved in the management of this case. Family members and friends were also contacted to obtain corroborative historical information.

Results: LE was diagnosed in this case based on clinical presentation with psychiatric symptoms, ruling out delirium due to infections, metabolic and other toxins as well as magnetic resonance imaging findings confirming temporal lobe changes.

Conclusion: LE is a known paraneoplastic syndrome (PNS) that may precede the diagnosis of an underlying malignancy. Recent advances in laboratory technology now allow for antibodies to be identified in specific malignancies. This behooves the clinicians to maintain a high level of diagnostic suspicion so that timely interventions with oncology can follow.
Do magnetic micro-swimmers move like eukaryotic cells?
Authors: Roper Marcus , Dreyfus Rémi , Baudry Jean , Fermigier Marc , Bibette Jérôme , Stone Howard A
Published: January 2008

Recent advances in micro-machining allow very small cargos, such as single red blood cells, to be moved by outfitting them with tails made of micrometre-sized paramagnetic particles yoked together by polymer bridges. When a time-varying magnetic field is applied to such a filament, it bends from side to side and propels itself through the fluid, dragging the load behind it. Here, experimental data and a mathematical model are presented showing the dependence of the swimming speed and direction of the magnetic micro-swimmer upon tunable parameters, such as the field strength and frequency and the filament length. The propulsion of the filament arises from the propagation of bending waves between free and tethered ends: here we show that this gives the micro-swimmer a gait that is intermediate between a eukaryotic cell and a waggled elastic rod. Finally, we extract from the model design principles for constructing the
fastest swimming micro-swimmer
by tuning experimental parameters.
Markowitz principles for multi-period portfolio selection problems with moments of any order
Authors: Chellathurai Thamayanthi , Draviam Thangaraj
Published: January 2008

The multi-period portfolio selection problem is formulated as a Markowitz mean–variance optimization problem in terms of time-varying means, covariances and higher-order and intertemporal moments of the asset prices. The crux lies in expressing the number of shares of any particular asset to be transacted on any future trading date, which is a non-anticipative process, as a polynomial of the changes in the discounted prices of all the risky assets. This results in the expected return of the portfolio being dependent on not only the means of the asset prices, but also the higher-order and intertemporal moments, and its variance being dependent on not only the second-order moments, but also the higher-order and intertemporal moments. As illustrations, we study the portfolio selection problems including the discrete version of the Merton problem. It is shown numerically that the efficient frontier obtained from Markowitz's discrete multi-period formulation coincides with that from Merton's continuous-time formulation when the number of rebalancing periods is ‘large’. The effects of dynamic trading, in particular volatility pumping, in comparison with a static single-period model are measured by a non-dimensional number, Dyn(
P
) (
P
, number of trading periods), which quantifies the relative gain due to dynamic trading. It is sufficient to rebalance the portfolio a few times in order to get more than 95% of the gain due to continuous trading.
Multimodal signals enhance decision making in foraging bumble-bees
Authors: Kulahci Ipek G , Dornhaus Anna , Papaj Daniel R
Published: January 2008

Multimodal signals are common in nature and have recently attracted considerable attention. Despite this interest, their function is not well understood. We test the hypothesis that multimodal signals improve decision making in receivers by influencing the speed and the accuracy of their decisions. We trained bumble-bees (Bombus impatiens) to discriminate between artificial flowers that differed either in one modality, visual (specifically, shape) or olfactory, or in two modalities, visual plus olfactory. Bees trained on multimodal flowers learned the rewarding flowers faster than those trained on flowers that differed only in the visual modality and, in extinction trials, visited the previously rewarded flowers at a higher rate than bees trained on unimodal flowers. Overall, bees showed a speed–accuracy trade-off; bees that made slower decisions achieved higher accuracy levels. Foraging on multimodal flowers did not affect the slope of the speed–accuracy relationship, but resulted in a higher intercept, indicating that multimodal signals were associated with consistently higher accuracy across range of decision speeds. Our results suggest that bees make more effective decisions when flowers signal in more than one modality, and confirm the importance of studying signal components together rather than separately.
Reproduction and nutritional stress are risk factors for Hendra virus infection in little red flying foxes (
Pteropus scapulatus
)
Authors: Plowright Raina K , Field Hume E , Smith Craig , Divljan Anja , Palmer Carol , Tabor Gary , Daszak Peter , Foley Janet E
Published: January 2008

Hendra virus (HeV) is a lethal paramyxovirus which emerged in humans in 1994. Poor understanding of HeV dynamics in
Pteropus
spp. (flying fox or fruit bat) reservoir hosts has limited our ability to determine factors driving its emergence. We initiated a longitudinal field study of HeV in little red flying foxes (LRFF;
Pteropus scapulatus
) and examined individual and population risk factors for infection, to determine probable modes of intraspecific transmission. We also investigated whether seasonal changes in host behaviour, physiology and demography affect host–pathogen dynamics. Data showed that pregnant and lactating females had significantly higher risk of infection, which may explain previously observed temporal associations between HeV outbreaks and flying fox birthing periods. Age-specific seroprevalence curves generated from field data imply that HeV is transmitted horizontally via faeces, urine or saliva. Rapidly declining seroprevalence between two field seasons suggests that immunity wanes faster in LRFF than in other flying fox species, and highlights the potentially critical role of this species in interspecific viral persistence. The highest seroprevalence was observed when animals showed evidence of nutritional stress, suggesting that environmental processes that alter flying fox food sources, such as habitat loss and climate change, may increase HeV infection and transmission. These insights into the ecology of HeV in flying fox populations suggest causal links between anthropogenic environmental change and HeV emergence.
Calcium dynamics integrated into signalling pathways that influence vertebrate axial patterning
Authors: Freisinger Christina M , Schneider Igor , Westfall Trudi A , Slusarski Diane C
Published: January 2008

Many aspects of animal development including fertilization as well as organ formation and function are dependent upon the dynamic release of calcium (Ca2+) ions. Although the controlled release and/or accumulation of Ca2+ions has been extensively studied, how the release dynamics produce a specific biological output in embryonic development is less clear. We will briefly summarize Ca2+sources, highlight data on endogenous Ca2+release in vertebrate embryos relevant to body plan formation and cell movement, and integrate pharmacological and molecular-genetic studies to lend insight into the signalling pathways involved. Finally, based onin vivoimaging in zebrafish genetic mutants, we will put forward the model that distinct Ca2+release dynamics lead to antagonism of the developmentally important Wnt/β-catenin signalling pathway, while sustained Ca2+release modulates cell polarization or directed migration.
Oligomerization of the influenza virus polymerase complex in vivo
Authors: Jorba Núria , Area Estela , Ortín Juan
Published: January 2008

The influenza virus polymerase is a heterotrimer formed by the PB1, PB2 and PA subunits and is responsible for virus transcription and replication. We have expressed the virus polymerase complex by co-transfection of the subunit cDNAs, one of which was tandem affinity purification (TAP)-tagged, into human cells. The intracellular polymerase complexes were purified by the TAP approach, involving two affinity chromatography steps, IgG–Sepharose and calmodulin–agarose. Gel-filtration analysis indicated that, although most of the purified polymerase behaved as a heterotrimer, a significant proportion of the purified material migrated as polymerase dimers, trimers and higher oligomers. Co-purification of polymerase complexes alternatively tagged in the same subunit confirmed that the polymerase complex might form oligomers intracellularly. The implications of this observation for virus infection are discussed.
Genome-wide analyses of phenylpropanoid-related genes in Populus trichocarpa, Arabidopsis thaliana, and Oryza sativa: the Populus lignin toolbox and conservation and diversification of angiosperm gene familiesThis article is one of a selection of papers published in the Special Issue on Poplar Research in Canada.
Authors: Hamberger Björn , Ellis Margaret , Friedmann Michael , de Azevedo Souza Clarice , Barbazuk Brad , Douglas Carl J.
Published: January 2008

The completion of the Populus trichocarpa (Torr. & A. Gray) (poplar) genome sequence offers an opportunity to study complete genome families in a third fully sequenced angiosperm (after Arabidopsis and rice) and to conduct comparative genomics studies of angiosperm gene family evolution. We focussed on gene families encoding phenylpropanoid and phenylpropanoid-like enzymes, and identified and annotated the full set of genes encoding these and related enzymes in the poplar genome. We used a similar approach to identify an analogous set of genes from the rice genome and generated phylogenetic trees for nine phenylpropanoid gene families from aligned poplar, Arabidopsis, and rice predicted protein sequences. This enabled us to identify the likely full set of bona fide poplar lignin-related phenylpropanoid genes (poplar “lignification toolbox”) apparent within well-defined clades in all phylogenetic trees. Analysis of expression data for poplar genes confirmed and refined annotations of lignin-related genes, which generally showed high expression in wood-forming tissues. Expression data from both poplar and Arabidopsis were used to make inferences regarding biochemical and biological functions of phenylpropanoid-like genes with unknown functions. The comparative approach also provided insights into the evolution of angiosperm phenylpropanoid-like gene families, illustrating lineage-specific clades as well as ancient clades containing genes with apparent conserved function.
Poplar leaf rusts: model pathogens for a model treeThis minireview is one of a selection of papers published in the Special Issue on Poplar Research in Canada.
Authors: Feau Nicolas , Joly David L. , Hamelin Richard C.
Published: January 2008

With the availability of the entire genome of the model tree Populus trichocarpa Torr. & A. Gray and the current genome sequencing project of its rust pathogen Melampsora larici-populina Kleb., rust–poplar interaction research has entered the genomic era. Recent genomics research on poplars has attempted to connect the genetic localizations of loci for qualitative and quantitative disease resistance with putative genes encoding resistance or signalling proteins. The interactions between these putative resistance genes and rust effectors remain unknown. Genomic resources developed for Melampsora spp. promise to contribute to our understanding of the molecular basis of pathogenicity by facilitating the isolation of pathogenicity genes. A multifaceted approach for the identification of such genes that relies largely on trimming and sequence data analysis has been developed. The strategy takes advantage of the resources available and combines EST libraries, bioinformatics data mining for extracellularly expressed secreted proteins, intra- and inter-specific comparative genomics, and testing for the presence of positive selection. It has resulted in the discovery of several putative candidate genes. In silico evidence for candidate genes will be further validated by robust experimental evidence through functional analyses.
Asymmetrical natural hybridization betweenPopulus deltoidesandP.balsamifera(Salicaceae)This note is one of a selection of papers published in the Special Issue on Poplar Research in Canada.
Authors: Hamzeh Mona , Sawchyn Christina , Périnet Pierre , Dayanandan Selvadurai
Published: January 2008

Natural hybridization has long been recognized as a means for gene flow between species and has important evolutionary consequences. Although hybridization is generally considered to be symmetrical, with both hybridizing species being equally likely to be the male or female parent, several studies have demonstrated the presence of asymmetrical hybridization and introgression from one species to the other. We investigated the direction of natural hybridization between two sympatric forest tree species in North America ( Populus deltoides Bartr. ex Marsh. and Populus balsamifera L.) using species-specific single nucleotide polymorphism (SNP) markers in both the nuclear and chloroplast genomes. All natural hybrid individuals, identified from morphological traits, had nuclear alleles corresponding to both parental species, while the chloroplast genotypes showed similarity to P. deltoides, indicating asymmetrical hybridization with P. deltoides as the maternal and P. balsamifera as the paternal donor species. This observed asymmetrical hybridization may be attributable to cytonuclear interactions.
Genetic control of Populus tremuloides sensitivity to metabolites of Hypoxylon mammatum
Authors: Kruger Brian M. , Manion Paul D.
Published: January 2008

Tissue culture plantlets derived from the vegetative buds of six aspen trees and from the seeds of controlled pollinations of these trees were bioassayed with culture filtrates from three isolates of Hypoxylon mammatum. Analysis of variance of parent and progeny bioassay responses revealed significant main effects and insignificant interaction, which suggests that metabolite sensitivity is a horizontally controlled trait. However, in certain crosses progeny response differed markedly from that of either parent. In these cases progeny were either far more or far less sensitive than the parents. This dramatic switching of sensitivity to the metabolites suggests that this trait is conditioned by a small number of genes. Key words: Populus tremuloides, Hypoxylon mammatum, phytotoxin.
Bud development in coastal Douglas-fir seedlings in response to different dormancy-induction treatments
Authors: MacDonald Joanne E. , Owens John N.
Published: January 2008

Bud development in response to different dormancy-induction treatments in coastal Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco var. menziesii) seedlings was investigated under commercial greenhouse conditions. There were three treatments: short day without moisture stress, short day with moisture stress, and long day with moisture stress. Within the first week in the short day treatments, neoformed-leaf initiation ended and bud-scale initiation began and ended. Rapid leaf initiation began in week 1 and was completed by week 5 for the short day with moisture stress treatment and week 6 for the short day without moisture stress treatment. Slow leaf initiation was completed by week 13. Crown cells became apparent within the pith during weeks 3–6; cell walls thickened between weeks 8 and 13. Within the first week of the long day with moisture stress treatment, neoformed-leaf initiation ended and bud-scale initiation began. Bud-scale initiation ended by week 3 or 4. Then slow leaf initiation began and continued until week 6. Rate of leaf initiation was rapid during weeks 8–10 and decreased slightly during weeks 10–13. By week 13, apical height had decreased markedly, indicating an imminent end to leaf initiation. Crown cells became apparent within the pith during weeks 5–13; cell walls thickened between weeks 10 and 13. Key words: bud development, dormancy induction, short days, moisture stress, Douglas-fir, seedlings.
Infrageneric phenetic relations in new world Panicum (Poaceae: Panicoideae: Paniceae): a numerical analysis
Authors: Zuloaga Fernando , Dubcovsky Jorge , Morrone Osvaldo
Published: January 2008

Numerical studies based on 64 characters placed 188 American species of the genus Panicum L. in 23 sections clustered in five major groups. The same major groups were obtained when the five characters that define the subgenera were excluded from the analyses. Groups 1 and 2 included C4 species. Species with an outer parenchymatous sheath in group 1 corresponded to subg. Panicum, whereas species with a single mestome sheath in group 2 corresponded to subg. Agrostoides. Group 3 included the intermediate C3–C4 species belonging to subg. Steinchisma. C3 sections were clustered together but arranged in a different way than previous classifications. Group 4 included sections from subg. Phanopyrum with basic chromosome number x = 10, whereas group 5 included the other sections of Phanopyrum with x = 9 together with sections from subg. Dichanthelium also with x = 9. The two subgroups of subg. Phanopyrum are not only different in chromosome number but also in inflorescence type and upper anthecium ornamentation. On the other hand the x = 9 sections of Phanopyrum remain in the same cluster with sections from subg. Dichanthelium in numerical analyses where basic chromosome number is removed. These results suggest the possibility of sinking Dichanthelium into Phanopyrum and then split the latter when more cytological data become available. Kranz syndrome and basic chromosome number were the characters with the highest contribution to the delimitation of the major groups. On the basis of these results different existing hypotheses on the classification of the genus Panicum are discussed. Key words: Panicum, numerical taxonomy.