bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of a New Method and Device for Adaptation and Suture of Tissues During Transoral Surgery: In Vitro and Cadaver Experiments
Authors: Lichtenberger György
Published: July 2005

OBJECTIVE:

The objective of this study was to present cadaver and model experiments of a technique using an instrument that may overcome the problems of achieving adaptation and suture of mucous membrane and other tissues during transoral surgery in narrow anatomical circumstances.

STUDY DESIGN:

The following interventions were carried out on cadavers: adaptation and suture of mucous membrane by uvulopalatopharyngoplasty (UPPP); release and anteroposition of the epiglottis and fixation to the vallecula or to the base of the tongue; denudation and closing the lumen of the larynx; release and retroposition and fixation of the epiglottis to the posterior part of the larynx; creation, adaptation, and suturing of mucosal flaps in the posterior part of the larynx; craniolateral mobilization and fixation of the vocal cord; submucous excision of excess tissues; and adaptation and suture of the edges of the mucosa.

RESULTS:

The safety and reduced need for microclips in surgeries in these areas can be accomplished by introducing the Ligature‐Suture device, which makes it possible to pass a suture under the tissues with a single movement.

CONCLUSIONS:

This new technique and instrument for the Ligature‐Suture device has the potential to be applied successfully in other fields of surgery. The main advantages of this technique are its simplicity and safety.
Ice-Core Pollen Record of Climatic Changes in the Central Andes during the last 400 yr
Authors: Liu Kam-biu , Reese Carl A. , Thompson Lonnie G.
Published: July 2005

This paper presents a high-resolution ice-core pollen record from the Sajama Ice Cap, Bolivia, that spans the last 400 yr. The pollen record corroborates the oxygen isotopic and ice accumulation records from the Quelccaya Ice Cap and supports the scenario that the Little Ice Age (LIA) consisted of two distinct phases�"a wet period from AD 1500 to 1700, and a dry period from AD 1700 to 1880. During the dry period xerophytic shrubs expanded to replace puna grasses on the Altiplano, as suggested by a dramatic drop in the Poaceae/Asteraceae (P/A) pollen ratio. The environment around Sajama was probably similar to the desert-like shrublands of the Southern Bolivian Highlands and western Andean slopes today. The striking similarity between the Sajama and Quelccaya proxy records suggests that climatic changes during the Little Ice Age occurred synchronously across the Altiplano.
From Conflict to Reconciliation: The Case of the Gondang Sabangunan in the Order of Discipline of the Toba Batak Protestant Church
Authors: Purba Mauly
Published: July 2005

Since German missionaries arrived in the Batak Lands in the early 1860s, the Toba Batak Protestant Church has struggled with its relationship to the indigenous cosmology and belief system known as adat. Using the performance of ceremonial music and dance as a case study, this article explores the impact of continuing local respect for adat on the development of Church policy over 140 years.
Badjao: Cinematic Representations of Difference in the Philippines
Authors: Toohey Aileen
Published: July 2005

This article examines the cinematic representation of identity through an analysis of the well-known Philippine film, Badjao. Produced in the late 1950s, Badjao successfully commercialized the idea and expression of conflict between the Tausug and Badjao ethnic groups. The study focuses on how the enactment and enunciation of identity through difference presented itself in cinema and how such representations, imbued with stereotypical cultural and religious codes, were re-formulations within nationalist discourses in the Philippines.
‘Class’ and Political Theatre: the Case of Melbourne Workers Theatre
Authors: D'Cruz Glenn
Published: July 2005

Traditionally, class has been an important category of identity in discussions of political theatre. However, in recent years the concept has fallen out of favour, partly because of changes in the forces and relations of capitalist production. The conventional Marxist use of the term, which defined an individual's class position in relation to the position they occupied in the capitalist production process, seemed anachronistic in an era of globalization. Moreover, the rise of identity politics, queer theory, feminism, and post-colonialism have proffered alternative categories of identity that have displaced class as the primary marker of self. Glenn D'Cruz reconsiders the role of class in the cultural life of Australia by examining the recent work of Melbourne Workers Theatre, a theatre company devoted to promoting class-consciousness, in relation to John Frow's more recent re-conceptualization of class. He looks specifically at two of the company's plays, the award-winning Who's Afraid of the Working Class? and The Waiting Room, with reference to Frow's work on class, arguing that these productions articulate a more complex and sophisticated understanding of class and its relation to politics of race and gender today. Glenn D'Cruz teaches drama and cultural studies at Deakin University, Australia.
Irish Rioters, Latin American Dictators, and Desperate Optimists' Play-boy
Authors: Swettenham Neal
Published: July 2005

The narrative process is inherently selective and consequently open to distortion and falsification. J. M. Synge humorously illustrated this in The Playboy of the Western World, in which his central character, Christy Mahon, reinvents himself through the telling and retelling of his own story. Play-boy, a much more recent performance work created by Desperate Optimists, takes as its opening gambit the riots that accompanied the first performances of this controversial Irish classic and adds a bewildering variety of other narrative materials to the mix—providing, as it does so, a tongue-in-cheek commentary on this story about stories. A detailed account of the show in performance and the manner in which the company construct their own tall tales initiates an investigation into how fact becomes fiction in the creation of new narrative accounts, narrative being considered as a participatory event that is both a psychological imperative and a ludic pleasure. Neal Swettenham lectures in drama at Loughborough University. His research into the role and status of narrative in contemporary theatre has led him to fresh examinations of both traditional story-based drama and avant-garde performance work. In particular, he has written about the plays of American dramatist Richard Foreman and is currently exploring the challenges presented to both actor and director by these texts.
British Brutalism, the ‘New European Drama’, and the Role of the Director
Authors: Nikcevic Sanja
Published: July 2005

The explosion of new theatre writing in Britain during and since the 'nineties contrasted with a dearth of original plays on continental Europe, east and west. Sanja Nikcevic attributes this in part to the dominance over the previous decades of the role of leading directors, who increasingly sought out raw materials to shape productions conforming to their own or their company's ideas. She traces the attempts in a number of countries to correct the imbalance by encouraging new writing through workshops and festivals—yet also how the explosion and importation of the British ‘in-yer-face’ style then affected the kind of new writing that was considered innovative and acceptable at such events. She argues against the claims made for the political significance of plays such as Sarah Kane's Blasted, suggesting rather that the acceptance of the normality of violence without reference to its social context negates the possibility of remedial action. A former Fulbright Scholar, Sanja Nikcevic is Head of the Department of English Literature at the University of Osijek, Croatia. Her full-length publications include The Subversive American Drama: Sympathy for Losers (1994), Affirmative American Drama: Long Live the Puritans (2003), and New European Drama: the Great Deception (2005). She was the founder and for eight years the president of the Croatian Centre of the International Theatre Institute.
National environmental performance: an empirical analysis of policy results and determinants
Authors: ESTY DANIEL C. , PORTER MICHAEL E.
Published: July 2005

Efforts to identify the determinants of environmental policy success at the national level have largely been anecdotal and case study based. This article seeks to identify empirically the factors that drive environmental performance as measured by levels of urban particulates and sulfur dioxide and energy use per unit of GDP. Although the data are imperfect and causal linkages cannot be definitively established, the statistical analysis presented suggests that environmental results vary not only with income levels as suggested by the environmental Kuznets Curve literature but also with both the sophistication of a nation's regulatory regime and, perhaps more notably, its broader economic and social context. Thus, at every level of development, countries face policy choices that determine environmental quality in important ways. Strong environmental performance appears to be positively correlated with competitiveness, putting into question the presumed trade-off between economic progress and environmental gains. Although preliminary, these results provide evidence that environmental decision making can be made more data driven and analytically rigorous.
Environmental regulation and the optimal location of the risk-averse firm under uncertainty
Authors: ISIK MURAT
Published: July 2005

The interrelationships between environmental regulations and firm location are essential features of economic development. This paper examines the optimal location of a competitive firm in response to environmental costs imposed by the abatement investment and taxes when the cost of the environmental regulation varies spatially under uncertainty. It contributes to the literature by incorporating the spatial setting into a risk-averse firm's location decision in the presence of environmental regulation uncertainty. An augmented cost of the abatement, input tax, or emission tax causes the risk-averse firm to locate closer to the output market. Uncertainty about environmental regulations also leads a risk-averse firm to locate closer to the output market. Policy implications of the results are discussed. The results have implications for the design and implementation of environmental and other development-related policies, environment–development debate, and trade–environment debate.
Determinants of compliance in the emissions compensation program in Santiago, Chile
Authors: PALACIOS MILAGROS , CHÁVEZ CARLOS
Published: July 2005

The Emissions Compensation (EC) Program in Santiago, Chile, has been affected from the beginning by the incidence of individual violations of maximum-emission capacity permits. Based on information at the individual source level, in this paper we develop and estimate a model explaining the individual compliance decision with emission capacity permits. Our results indicate that the compliance behavior of sources during the period 1993–1999 do in fact depend on their individual characteristics. Among other factors, type of equipment used, industrial sector to which the source belongs, fuel type used, the initial allocation of emission capacity permits to the source, and population density as well as average income in the area where the source is located, turn out to be relevant. Furthermore, the evidence does not allow us to reject the presence of structural change in the individual decision to comply with permit holdings because of the introduction of natural gas in the Metropolitan Region of Santiago at the end of 1997.
Contrasting responses of forest ecosystems to rising atmospheric CO2: Implications for the global C cycle
Authors: DeLucia E. H. , Moore D. J. , Norby R. J.
Published: July 2005

In two parallel but independent experiments, Free Air CO2 Enrichment (FACE) technology was used to expose plots within contrasting evergreen loblolly pine (Pinus taeda L.) and deciduous sweetgum (Liquidambar styraciflua L.) forests to the level of CO2 anticipated in 2050. Net primary production (NPP) and net ecosystem production (NEP) increased in both forests. In the year 2000, after exposing pine and sweetgum to elevated CO2 for approximately 5 and 3 years, a complete budget calculation revealed increases in net ecosystem production (NEP) of 41% and 44% in the pine forest and sweetgum forest, respectively, representing the storage of an additional 174 gC m−2 and 128 gC m−2 in these forests. The stimulation of NPP without corresponding increases in leaf area index or light absorption in either forest resulted in 23–27% stimulation in radiation‐use efficiency, defined as NPP per unit absorbed photosynthetically active radiation. Greater plant respiration contributed to lower NPP in the loblolly pine forest than in the sweetgum forest, and these forests responded differently to CO2 enrichment. Where the pine forest added C primarily to long‐lived woody tissues, exposure to elevated CO2 caused a large increase in the production of labile fine roots in the sweetgum forest. Greater allocation to more labile tissues may cause more rapid cycling of C back to the atmosphere in the sweetgum forest compared to the pine forest. Imbalances in the N cycle may reduce the response of these forests to experimental exposure to elevated CO2 in the future, but even at the current stimulation observed for these forests, the effect of changes in land use on C sequestration are likely to be larger than the effect of CO2‐induced growth stimulation.
Intercomparison and closure calculations using measurements of aerosol species and optical properties during the Yosemite Aerosol Characterization Study
Authors: Malm William C. , Day Derek E. , Carrico Christian , Kreidenweis Sonia M. , Collett Jeffrey L. , McMeeking Gavin , Lee Taehyoung , Carrillo Jacqueline , Schichtel Bret
Published: July 2005

Physical and optical properties of inorganic aerosols have been extensively studied, but less is known about carbonaceous aerosols, especially as they relate to the non‐urban settings such as our nation's national parks and wilderness areas. Therefore an aerosol characterization study was conceived and implemented at one national park that is highly impacted by carbonaceous aerosols, Yosemite. The primary objective of the study was to characterize the physical, chemical, and optical properties of a carbon‐dominated aerosol, including the ratio of total organic matter weight to organic carbon, organic mass scattering efficiencies, and the hygroscopic characteristics of a carbon‐laden ambient aerosol, while a secondary objective was to evaluate a variety of semi‐continuous monitoring systems. Inorganic ions were characterized using 24‐hour samples that were collected using the URG and Interagency Monitoring of Protected Visual Environments (IMPROVE) monitoring systems, the micro‐orifice uniform deposit impactor (MOUDI) cascade impactor, as well as the semi‐continuous particle‐into‐liquid sampler (PILS) technology. Likewise, carbonaceous material was collected over 24‐hour periods using IMPROVE technology along with the thermal optical reflectance (TOR) analysis, while semi‐continuous total carbon concentrations were measured using the Rupprecht and Patashnick (R&P) instrument. Dry aerosol number size distributions were measured using a differential mobility analyzer (DMA) and optical particle counter, scattering coefficients at near‐ambient conditions were measured with nephelometers fitted with PM10 and PM2.5 inlets, and “dry” PM2.5 scattering was measured after passing ambient air through Perma Pure Nafion® dryers. In general, the 24‐hour “bulk” measurements of various aerosol species compared more favorably with each other than with the semi‐continuous data. Semi‐continuous sulfate measurements correlated well with the 24‐hour measurements, but were biased low by about 0.15 μg/m3. Semi‐continuous carbon concentrations did not compare favorably with 24‐hour measurements. Fine mass closure calculations suggested that the factor for estimating organic mass from measurements of carbon was approximately 1.8. Furthermore, fine scattering closure calculations showed that the use of 4.0 m2/g for the fine organic mass scattering coefficient was an underestimate by at least 30% for periods with high organic mass concentrations.
Adjoint inverse modeling of black carbon during the Asian Pacific Regional Aerosol Characterization Experiment
Authors: Hakami A. , Henze D. K. , Seinfeld J. H. , Chai T. , Tang Y. , Carmichael G. R. , Sandu A.
Published: July 2005

An adjoint model is used for inverse modeling of black carbon during the Asian Pacific Regional Aerosol Characterization Experiment (ACE‐Asia). We use the four‐dimensional variational data assimilation (4D‐Var) approach to optimally recover spatially resolved anthropogenic and biomass‐burning emissions and initial and boundary conditions of black carbon. Boundary conditions and biomass‐burning emissions are assigned daily scaling factors. Anthropogenic emissions are scaled by a combination of daily and monthly scaling factors. Simulation results are compared to various observations of black carbon concentrations during the campaign. Measurements at five islands and on board the research vessel Ronald H. Brown are used for inverse modeling. Different levels of constraints are examined for inversion, and a case with 62% reduction in the total square errors is chosen. The assimilated results are compared with the observations on board the Twin Otter aircraft that were not used for assimilation. Among the scaled variables, anthropogenic emissions are the most significant, followed by the boundary conditions. The domain‐wide emissions inventory does not change significantly as a result of the assimilation, but sizable changes occur on the subregional level. Most noticeably, anthropogenic emissions over southeastern China are reduced while those in northeast China and Japan are increased.
Moho geometry and upper mantle images of northeast India
Authors: Ramesh D. S. , Ravi Kumar M. , Uma Devi E. , Solomon Raju P. , Yuan X.
Published: July 2005

Images of the crust and mantle beneath northeast India obtained by 2D migration of ∼1000 broadband P‐receiver functions clearly trace a northward dipping Moho from the Himalayan foredeep reaching depths up to 50 km further north beneath the Himalayan convergence zone. Also, these images reveal presence of largely coherent 410‐km and 660‐km discontinuities that conform to the IASP91 model. Marginal variations in the depth of the 410‐km interface are observed, that appear region specific. The thickness of the mantle transition zone does not deviate significantly from a global average of ∼250 km. Interestingly, our results reveal consistent presence of a signal from an interface around 300 km. Origin of such a boundary, known as X‐discontinuity and unrelated to the Lehmann discontinuity, is discussed. Possible presence of the X‐discontinuity from the Indian region is reported here for the first time.
Northward extension of intense monsoonal activity into the southwestern United States
Authors: Diem Jeremy E.
Published: July 2005

Although it is centered in northwestern Mexico, the Mexican monsoon also has been shown to impact portions of the southwestern United States. To provide more information about the spatial distribution of monsoonal impacts in the Southwest, this study employed multiple linear regression modeling to reduce local topographic impacts on monsoonal precipitation to reveal intense monsoonal activity within the Gila River basin. The precipitation data were daily precipitation totals from 115 stations from June 16–September 15 of 1996–2002. An intense monsoonal zone was found in the south‐central portion of the basin. Therefore, intense monsoonal activity associated with the Sierra Madre Occidental in northwestern Mexico extended into south‐central and southeastern Arizona but not into New Mexico.
Role of hysteresis in propagating acoustic waves in soils
Authors: Lu Zhiqu
Published: July 2005

To determine the role of hysteresis in propagating acoustic waves in soils, the stress/strain and sound speed/strain behaviors of soils are studied in triaxial cell tests. A series of quasi‐static hysteresis loops with strain amplitudes ranging from 3 × 10−5 to 2 × 10−4 are formed during the tests. The slope of a hysteresis loop is compared with the dynamic elastic modulus from a sound speed measurement. It is found that the hysteresis slope linearly correlates with the dynamic modulus and decreases with the strain amplitude of the hysteresis loop. This discovery supports the hypothesis that acoustic wave propagation in a soil is a hysteresis process. Hysteresis might be the major source of the acoustic nonlinearity of soils.
Effect of Al on the sharpness of the MgSiO3 perovskite to post‐perovskite phase transition
Authors: Akber‐Knutson S. , Steinle‐Neumann G. , Asimow P. D.
Published: July 2005

By means of static ab‐initio computations we investigate the influence of Al on the recently discovered perovskite to post‐perovskite phase transition in MgSiO3. We examine three substitution mechanisms for Al in the two structures: MgSi → AlAl; SiSiO → AlAl□; and Si → AlH. The substitutions introducing oxygen vacancies (highly unfavorable, energetically) and water (favorable) both lower the 0 Kelvin transition pressure, whereas charge coupled substitution increases it relative to 105 GPa for pure MgSiO3. From the transition pressures for 0, 6.25, and 100 mol% charge coupled Al2O3 incorporation and simple solution theories, we estimate the phase diagram of Al‐bearing MgSiO3 at low Al concentrations. Assuming the Clapeyron slope is independent of Al concentration, we find the perovskite‐to‐post‐perovskite transition region to span 127–140 GPa, at 6.25 mol% Al2O3. When the upper pressure limit is bounded by the core‐mantle boundary, the phase coexistence region has width 150 km.
Direct measurements of the mean flow and eddy kinetic energy structure of the upper ocean circulation in the NE Atlantic
Authors: Knutsen Øyvind , Svendsen Harald , Østerhus Svein , Rossby Tom , Hansen Bogi
Published: July 2005

The upper ocean circulation in the sub‐polar northeast Atlantic has been a challenge to quantify due to strong and variable wind‐forcing, and strong and variable deep currents that lead to large uncertainties in the use of the standard dynamical method. Since 1999 we have been operating an acoustical Doppler current profiler on a container vessel that operates between Denmark and Greenland to repeatedly sample upper ocean currents across the northeast Atlantic. Individual transects exhibit a highly energetic mesoscale variability, but ensemble‐averaging of the sections reveals a striking organization of the mean field along the Reykjanes Ridge: a distinct southward flow along its eastern slope and two clearly defined peaks with seasonal modulation flowing to the north along its western slope. Higher values of eddy kinetic energy (about 150–600 cm2 s−2) are observed along the transect, O(1.5) greater than surface drifter estimates.
Interseismic coupling and asperity distribution along the Kamchatka subduction zone
Authors: Bürgmann Roland , Kogan Mikhail G. , Steblov Grigory M. , Hilley George , Levin Vasily E. , Apel Edwin
Published: July 2005

GPS measurements of interseismic horizontal surface velocities reveal the degree of kinematic coupling of the plate boundary thrust along the Kamchatka subduction zone from about 51° to 57°N latitude. Inversions for the distribution of aseismic slip rate along the ∼15°NW dipping underthrust suggest a nonslipping plate interface in southern Kamchatka above ∼50 km depth, along the segment that ruptured in the Mw = 9, 1952 earthquake. North of ∼53°N, the subduction interface experiences significant aseismic slip, consistent with the lower seismic moment release in M ≤ 8.5 earthquakes along this portion of the subduction zone. The GPS velocities are consistent with a boundary element forward model in which historic earthquake rupture zones are represented as locked asperities, surrounded by a zero shear stress subduction interface loaded by plate convergence. Models in which the complete rupture zones of historic earthquakes are considered locked greatly overpredict the degree of kinematic coupling. Reducing the area of the locked model asperities to the central 25% area of historic rupture zones fits the data well, suggesting that large earthquakes involve small fully locked core asperities surrounded by conditionally stable portions of the plate interface. Areas of low aseismic slip rate appear to be roughly correlated with areas of low isostatic gravity anomalies over offshore forearc basins, while less coupled portions of the Kamchatka subduction zone coincide with high‐gravity anomalies offshore of two peninsulas, possibly related to the subduction of the Emperor‐Meji seamount chain and the Kruzenstern fracture zone.
Effects in vitro and in vivo by apomorphine in the rat corpus cavernosum
Authors: Matsumoto Kenshi , Yoshida Masaki , Andersson Karl‐Erik , Hedlund Petter
Published: July 2005

The study was performed to clarify if apomorphine at the level of the rat corpus cavernosum can produce erectile responses or interfere with nerve‐induced penile erection.

Apomorphine (10−9–10−4 M) exhibited a 10‐fold higher potency to relax phenylephrine (Phe)‐ than endothelin‐1 (ET‐1)‐induced contractions. Relaxant effects of apomorphine in Phe‐activated corpus cavernosum did not change tissue levels of cyclic nucleotides, and were unaffected by inhibition of the synthesis of nitric oxide, or by inhibition of the soluble guanylate cyclase.

Relaxations by apomorphine of ET‐1‐contracted rat corpus cavernosum were not influenced by α2‐adrenoceptor blockade (yohimbine, 10−7 M), or by the dopamine D1‐like receptor antagonist SCH 23390 (10−6 M). Clozapine (10−6 M), a proposed dopamine D2‐like receptor antagonist, partly reduced apomorphine‐induced relaxations, and significantly altered the −log IC50 value for apomorphine.

Nerve‐induced contractions of the rat corpus cavernosum were attenuated by apomorphine in a concentration‐dependent and biphasic manner. Yohimbine (10−7 M) abolished the biphasic concentration–response pattern. SCH 23390 (10−6 M) attenuated the inhibitory effects of apomorphine on contractions, and significantly altered the −log IC50 value for the compound.

In anesthetized rats (50 mg kg−1 pentobarbital sodium, 10 mg kg−1 ketamine), intracavernous apomorphine (100, 300, or 1000 nmol) did not have effects on basal cavernous pressure under resting conditions, and did not affect filling or emptying rates, or peak pressures of the rat corpus cavernosum during submaximal activation of the cavernous nerve. In awake rats, apomorphine produced a maximal number of erections at 300 nmol kg−1.

In the rat isolated corpus cavernosum, pre‐ and postjunctional effects of apomorphine appear to involve dopamine D1‐ and D2‐like receptors, as well as α‐adrenoceptors. At relevant systemic doses of apomorphine, peripheral effects of the compound are unlikely to contribute to its proerectile effects in rats.

British Journal of Pharmacology (2005) 146, 259–267. doi:10.1038/sj.bjp.0706317
No Down‐Regulation of Leaf Photosynthesis in Mature Forest Trees after Three Years of Exposure to Elevated CO2
Authors: Zotz G. , Pepin S. , Körner C.
Published: July 2005

Abstract: The photosynthetic responses of six species of mature forest trees to long‐term exposure to elevated CO2 (ca. 530 ppm) were determined at the Swiss Canopy Crane (SCC) site near Basel, Switzerland. In the third year of growth in elevated CO2, using web‐FACE technology, net photosynthesis (As) in fully sunlit, upper canopy foliage was stimulated by ca. 40 % compared to ambient controls. This enhancement did not differ from the instantaneous increase in A5 found in ambient‐grown leaves that were temporarily measured at elevated CO2. A complete lack of down‐regulation of photosynthesis was found in all species and in both the early and the late growing season. Neither was leaf nitrogen content significantly affected by long‐term exposure to elevated CO2. Our results document a persistent enhancement in leaf level photosynthesis in response to elevated CO2 in mature forest trees over a period of three years. Circumstantial evidence suggests that the additional assimilates feed into large sinks other than stem and shoot growth.
Ultrastructure and Lipid Alterations Induced by Cadmium in Tomato (Lycopersicon esculentum) Chloroplast Membranes
Authors: Djebali W. , Zarrouk M. , Brouquisse R. , El Kahoui S. , Limam F. , Ghorbel M. H. , Chaïbi W.
Published: July 2005

Abstract: The effects of cadmium (Cd) uptake on ultrastructure and lipid composition of chloroplasts were investigated in 28‐day‐old tomato plants (Lycopersicon esculentum var. Ibiza F1) grown for 10 days in the presence of various concentrations of CdCl2. Different growth parameters, lipid and fatty acid composition, lipid peroxidation, and lipoxygenase activity were measured in the leaves in order to assess the involvement of this metal in the generation of oxidative stress. We first observed that the accumulation of Cd increased with external metal concentration, and was considerably higher in roots than in leaves. Cadmium induced a significant inhibition of growth in both plant organs, as well as a reduction in the chlorophyll and carotenoid contents in the leaves. Ultrastructural investigations revealed that cadmium induced disorganization in leaf structure, essentially marked by a lowered mesophyll cell size, reduced intercellular spaces, as well as severe alterations in chloroplast fine structure, which exhibits disturbed shape and dilation of thylakoid membranes. High cadmium concentrations also affect the main lipid classes, leading to strong changes in their composition and fatty acid content. Thus, the exposure of tomato plants to cadmium caused a concentration‐related decrease in the fatty acid content and a shift in the composition of fatty acids, resulting in a lower degree of fatty acid unsaturation in chloroplast membranes. The level of lipid peroxides and the activity of lipoxygenase were also significantly enhanced at high Cd concentrations. These biochemical and ultrastructural changes suggest that cadmium, through its effects on membrane structure and composition, induces premature senescence of leaves.
Transgenic GFP as a Molecular Marker for Approaches to Quantify Pollination Mechanism and Gene Flow in Arabidopsis thaliana
Authors: Tan Y.‐Y. , Xu H.‐H. , Tao W.‐J. , Hoffmann M. H. , Wang X.‐F. , Lu Y.‐T.
Published: July 2005

Abstract: Arabidopsis thaliana is commonly regarded as a self‐pollinated plant. We observed that the stigma in each flower of A. thaliana cannot be pollinated by its own pollen in the early phases of the flowering process, when the anthers had dehisced but the filaments were still too short for the pollen to be deposited on the stigma. In the later stages, after elongation of the filaments, self‐pollination can occur. After artificial pollination of the flower of a wild plant with GFP transgenic pollen grains in earlier stages of flowering, GFP expressed within epidermal cells was detected in some of the offspring (26.1 ‐ 57.1 %). Wind‐mediated pollen dispersal was poor but is likely to exist in natural habitats, while insects were observed visiting flowers of A. thaliana in natural and experimental populations. We constructed an experimental population consisting of 28 GFP transgenic plants and 240 wild plants and examined gene flow in the population. The result was that the distance of gene flow was limited to 0.5 m. 22 offspring with expressed GFP were found in 28 299 filial individuals examined, which suggested a relatively low outcrossing rate (0.74 %). We conclude that outcrossing in populations of A. thaliana is mainly due to insect pollination. The data on gene flow could be useful to assess the ecological hazards of experimental transgene combinations.
Nuclear DNA Content and Chromosome Number in Some Diploid and Tetraploid Centaurea (Asteraceae: Cardueae) from the Dalmatia Region
Authors: Siljak‐Yakovlev S. , Solic M. E. , Catrice O. , Brown S. C. , Papes D.
Published: July 2005

Abstract: Given the paucity of information about genome size in the genus Centaurea, nuclear DNA content of 15 Centaurea taxa, belonging to four subgenera and six different sections, has been investigated for the first time. The sample concerns 21 populations from the Dalmatia region of Croatia. The 2C DNA content and GC percentage were assessed by flow cytometry and chromosome number was determined using standard methods. Genome size of studied Centaurea ranged from 2C = 1.67 to 3.72 pg. These results were in accordance with chromosome number and especially with ploidy level that varies throughout this group; 2C DNA values ranged from 1.67 to 3.43 pg for diploid, and from 3.19 to 3.72 for polyploid taxa. No significant intraspecific variations of DNA amount were found between two subspecies of C. visiani and C. ragusina, nor between two varieties of C. gloriosa. However, some populations of C. glaberrima and C. cuspidata showed a significant difference in DNA amount. Three different basic chromosome numbers were observed in studied species (x = 9, 10, and 11). The most frequent basic number was x = 9. C. rupestris, C. ragusina ssp. ragusina, and C. r. ssp. lungensis possessed x = 10 and C. tuberosa x = 11. The species with a basic chromosome number of x = 9 had a small genome size and the smallest chromosomes (on average 0.09 to 0.12 pg/chromosome) but frequently present polyploidy. Centaurea ragusina ssp. ragusina and C. r. ssp. lungensis had a mean base composition 41.3 % GC.
IUPAC-NIST Solubility Data Series. 81. Hydrocarbons with Water and Seawater–Revised and Updated Part 1. C5 Hydrocarbons with Water
Authors: Maczynski Andrzej , Shaw David G. , Goral Marian , Wisniewska-Goclowska Barbara , Skrzecz Adam , Maczynska Zofia , Owczarek Iwona , Blazej Krystyna , Haulait-Pirson Marie-Claire , Kapuku F. , Hefter Glenn T. , Szafranski Andrzej
Published: July 2005

The mutual solubility and related liquid–liquid equilibria of C5 hydrocarbons with water are exhaustively and critically reviewed. Reports of experimental determination of solubility in 13 chemically distinct binary systems for which data appeared in the primary literature prior to end of 2002 are compiled. For seven systems sufficient data are available to allow critical evaluation. All data are expressed as mass percent and mole fraction as well as the originally reported units. In addition to the standard evaluation criteria used throughout the Solubility Data Series, a new method based on the evaluation of the all experimental data for a given homologous series of saturated or unsaturated aliphatic hydrocarbons was used.
IUPAC-NIST Solubility Data Series. 81. Hydrocarbons with Water and Seawater—Revised and Updated. Part 4. C6H14 Hydrocarbons with Water
Authors: Goral Marian , Wisniewska-Goclowska Barbara , Skrzecz Adam , Owczarek Iwona , Blazej Krystyna , Haulait-Pirson Marie-Claire , Hefter Glenn T. , Kapuku F. , Maczynska Zofia , Young Colin L.
Published: July 2005

The mutual solubility and related liquid–liquid equilibria of C6H14 hydrocarbons with water are exhaustively and critically reviewed. Reports of experimental determination of solubility in five chemically distinct binary systems that appeared in the primary literature prior to end of 2002 are compiled. For all five systems sufficient data are available to allow critical evaluation. All data are expressed as mass percent and mole fraction as well as the originally reported units. In addition to the standard evaluation criteria used throughout the Solubility Data Series, a new method based on the evaluation of the all experimental data for a given homologous series of saturated or unsaturated aliphatic hydrocarbons was used.
The Dissociation Enthalpies of Terminal (N–O) Bonds in Organic Compounds
Authors: Acree William E. , Pilcher Geoffrey , Ribeiro da Silva Maria D. M. C.
Published: July 2005

Dissociation enthalpies of terminal (N–O) bonds, DH∘(N–O), in amine N-oxides, nitrile N-oxides, pyridine N-oxides, quinoxaline 1,4-dioxides, furoxans, nitrones, azoxy-derivatives, azo-N,N-dioxides, nitro compounds, nitramines, and alkyl nitrates are calculated from published enthalpy of formation, enthalpy of sublimation, and enthalpy of vaporization data. For each class of organic compounds, the calculated DH∘(N–O) values are critically evaluated. The derived DH∘(N–O) values can be used to estimate enthalpies of formation of other molecules in each of these classes of organic compounds.
Drift wave versus interchange turbulence in tokamak geometry: Linear versus nonlinear mode structure
Authors: Scott Bruce D.
Published: July 2005

The competition between drift wave and interchange physics in general E-cross-B drift turbulence is studied with computations in three-dimensional tokamak flux tube geometry. For a given set of background scales, the parameter space can be covered by the plasma β and drift wave collisionality. At large enough plasma β the turbulence breaks out into ideal ballooning modes and saturates only by depleting the free energy in the background pressure gradient. At high collisionality it finds a more gradual transition to resistive ballooning. At moderate β and collisionality it retains drift wave character, qualitatively identical to simple two-dimensional slab models. The underlying cause is the nonlinear vorticity advection through which the self-sustained drift wave turbulence supersedes the linear instabilities, scattering their structure apart before they can grow, imposing its own physical character on the dynamics. This vorticity advection catalyses the gradient drive, while saturation occurs solely through turbulent mixing of pressure disturbances. This situation persists in the whole of tokamak edge parameter space. Both simplified isothermal models and complete warm ion models are treated.
Non-Born–Oppenheimer treatment of the H2 Hookean molecule
Authors: Ludeña Eduardo V. , Lopez Xabier , Ugalde Jesus M.
Published: July 2005

We show that the exact non-Born–Oppenheimer Schrödinger equation for the Hookean diatomic molecule H2 (a two-proton, two-electron system where the electron-proton interaction is harmonic while the proton-proton and electron-electron interactions are Coulombic) can be decoupled into equations describing the relative motion of the electrons, the relative motion of nuclei, the motion of a collective mode representing a three-dimensional harmonic oscillator, and the motion of a free particle expressed as a linear combination of the individual center-of-mass coordinates of the nuclei and electrons. Analytic solutions to the relative motion of electrons can be readily obtained for the given values of the harmonic coupling constant. However, exact analytic solutions to the equation for the relative motion of the nuclei cannot be obtained simultaneously due to the fact that the harmonic constants in these two equations are coupled. For this reason, we present for the relative nuclear motion approximate analytic wave functions, one of them obtained variationally and the other by a series solution where the coefficients are determined recursively. We also explore a variational solution to the Taylor-series expansion of the nuclear interaction potential. Properties of the electronic and nuclear intracule densities are examined at different values of the coupling constant. An interesting result of the present non-Born–Oppenheimer treatment of this harmonic model is the fact that the relative nuclear motion occurs in a highly correlated regime. This leads in a natural way to a spatial localization of the nuclei akin to Wigner electronic crystallization.
Anisotropic thermal expansion of strontium barium niobate
Authors: Qadri Syed B. , Bellotti Jeffrey A. , Garzarella Anthony , Wu Dong Ho
Published: July 2005

Strontium barium niobate is a tungsten-bronze ferroelectric crystal having a tetragonal unit cell. Low-temperature x-ray diffraction studies were performed on a single crystal of Sr0.75Ba0.25Nb2O6 to determine the thermal expansivity along the a- and c-axes. Negative thermal expansion was observed along the c direction while a positive thermal expansion was measured along the a axis. The anisotropic thermal expansion behavior is explained as arising due to the geometry of the crystal structure.
Effect of the extinction coefficient on the extraction efficiency of ZnS:Mn thin-film phosphors grown on two-dimensional nanorod substrates
Authors: Do Young Rag , Kwak Hyon Tae , Sung Myung Mo
Published: July 2005

We have studied the effects of varying the extinction coefficient of two-dimensional (2D) nanorod-assisted ZnS:Mn thin-film phosphors on their photoluminescence extraction efficiency. The finite-difference time-domain method was employed for the design and analysis of 2D nanorod-assisted thin-film phosphors. Using a nanorod pattern with a depth of 200 nm, a lattice constant of 600 nm, and a radius of 180 nm, the extraction efficiency of a transparent ZnS:Mn thin-film phosphor is predicted theoretically to increase by a factor of more than ∼9.1. Experiments have shown that incorporation of the 2D SiO2 nanorod layer only improves the light extraction efficiency over that of a conventional ZnS:Mn thin-film phosphor by a factor of ∼4.0. We discuss the reasons for this mismatch between the theoretical and experimental extraction efficiencies, in order to further improve the extraction efficiency of ZnS-based thin-film phosphors.
Cr
3
+
→
Nd
3
+
energy transfer in the YAl3(BO3)4 nonlinear laser crystal
Authors: Bovero E. , Cavalli E. , Jaque D. , García Solé J. , Speghini A. , Bettinelli M.
Published: July 2005

The energy transfer between Cr3+ and Nd3+ ions in Cr3+, Nd3+:YAl3(BO3)4 (YAB) codoped crystals has been investigated by means of steady-state and time-resolved laser spectroscopies. The mainly nonradiative character of the energy transfer has been evidenced from the comparison between the emission spectra and the donor fluorescence decays. The analysis of the donor decay profiles has been used to determine the main dipole–dipole character of the transfer, in excellent agreement with the predictions made from the Dexter [J. Chem Phys. 21, 836 (1953)] model, as well as with the dependence of the energy-transfer rates on the acceptor concentration. The temperature behavior of the transfer rate has been analyzed considering the thermal-induced population redistribution between the E2 and T24 states of Cr3+ ions and the existence of the phonon-assisted energy transfer. We have obtained that 80% of the Cr3+→Nd3+ energy transfer in YAB is taking place without the assistance of lattice phonons whereas almost 20% is taking place through multiphonon emission.
Electrical properties and logic function of multibranch junction structures
Authors: Wallin D. , Xu H. Q.
Published: July 2005

We report on room-temperature electrical measurements of multibranch junction (MBJ) devices made from a semiconductor heterostructure. We show that the MBJ devices exhibit an interesting electrical property. If the voltage output at one branch is measured as a function of the voltages inputs to all the other branches, the output voltage is determined predominately by the most negative, or the lowest, voltage applied. The property arises from the nature of the voltage-induced ballistic electron transport in the MBJ device, and can in general be observed in other nanoscale MBJ structures. We also demonstrate the realization of very compact multi-input logic gates with the MBJ structures.
Spectral response of a gigahertz-range nanomechanical oscillator
Authors: Gaidarzhy Alexei , Zolfagharkhani Guiti , Badzey Robert L. , Mohanty Pritiraj
Published: July 2005

We report the measurement and simulation of the transverse displacement spectrum of a multi-element nanomechanical oscillator at previously inaccessible frequencies of up to 3GHz. The detected displacement signal is enhanced in the high-frequency range by the presence of high-order resonance modes generated by coherent motion of individual elements. The spectrum reveals a rich structure with groups of peaks forming quasibands. The spectral structure is qualitatively analogous to atomic emission spectra.
Charge-carrier trapping in polyfluorene-type conjugated polymers
Authors: Kadashchuk A. , Schmechel R. , von Seggern H. , Scherf U. , Vakhnin A.
Published: July 2005

The trap spectrum of a fluorene-based conjugated polymer poly[9,9-bis(2-ethylhexyl)fluorene-2,7-diyl] (PF2∕6) and poly[9,9-bis(2-ethylhexyl)fluorene-2,7-diyl] end capped with hole-transporting moieties N, N-bis(4-methylphenyl)-N-phenylamine (PF2∕6am10) is investigated by means of thermally stimulated current (TSC) and thermally stimulated luminescence (TSL) techniques. A high-temperature TSC peak observed at 240K in PF2∕6 is strongly affected by photooxidation and could be identified as electron trap with a depth of about 0.6eV. It is ascribed to on-chain keto defects in the polymer. In contrast, end capping of PF2∕6 led to the appearance of a moderately deep trap for holes (Ea=0.24eV) responsible for a TSC peak at 120K. On the other hand, TSC data of this polymer reveal no keto-related traps for electrons implying much higher stability of PF2∕6am10 against oxidation. Besides the deep electron trap in PF2∕6, a very low-temperature TSC peak at about 60K appears in PF2∕6 samples and correlates perfectly with thermally stimulated luminescence data. It is ascribed to shallow hole trapping most probably related to the tail states of the intrinsic density-of-state distribution. In general, it was found that the TSC in PF2∕6 samples is detectable only when a sufficiently high load voltage is applied during optical trap filling. The TSC spectra exhibit a striking difference with the polarity of load voltage for conjugated polymers, implying an important role of electrodes on the charge-carrier photogeneration in these polymers.
Observation of switching of magnetic particle arrays with weak dipole interaction field effects
Authors: Abraham David W. , Lu Y.
Published: July 2005

We have measured the subtle changes in magnetic reversal of weakly interacting arrays of submicrometer magnetic particles as a function of particle spacing and interpreted the data within the context of a model assuming a normal distribution of switching fields plus dipole fields between particles. The measurements were performed on a Kerr magnetometer and showed the changes in switching characteristics of the particle array as a function of array spacing in the two in-plane directions. The Monte Carlo calculations included the effect of changing particle pitch in two in-plane directions and explained the characteristic change in sharpness of the switching transition alternatively as a frustration or as an enhanced sharpness due to cascading transitions, depending on whether the hard- or easy-axis dipole coupling is dominant. This method is extensible to nanoscale particles and provides an estimate of the moment of the particle, a measurement which is difficult to obtain via other experimental methods.
Size control of InAs quantum dashes
Authors: Sauerwald A. , Kümmell T. , Bacher G. , Somers A. , Schwertberger R. , Reithmaier J. P. , Forchel A.
Published: July 2005

Self-organized InAs quantum dashes grown on In0.53Ga0.23Al0.24As∕InP have been investigated by chemically sensitive scanning transmission electron microscopy. The quantum dashes, which consist of pure InAs, exhibit a triangular cross section. Most important, the quantum dash size depends linearly on the nominal InAs layer thickness and can be varied by a factor of 3 without changing the height∕width ratio. Thus, the emission wavelength can be controlled between 1.37 and 1.9μm without modifying shape and composition of the quantum dashes by adjusting a single growth parameter.