bluuebunny/crossref_metadata_2025 huggingface dataset:
Composition Markov chains of multinomial type
Authors: Zhou Hua , Lange Kenneth
Published: April 2009

Suppose thatnidentical particles evolve according to the same marginal Markov chain. In this setting we study chains such as the Ehrenfest chain that move a prescribed number of randomly chosen particles at each epoch. The product chain constructed by this device inherits its eigenstructure from the marginal chain. There is a further chain derived from the product chain called the composition chain that ignores particle labels and tracks the numbers of particles in the various states. The composition chain in turn inherits its eigenstructure and various properties such as reversibility from the product chain. The equilibrium distribution of the composition chain is multinomial. The current paper proves these facts in the well-known framework of state lumping and identifies the column eigenvectors of the composition chain with the multivariate Krawtchouk polynomials of Griffiths. The advantages of knowing the full spectral decomposition of the composition chain include (a) detailed estimates of the rate of convergence to equilibrium, (b) construction of martingales that allow calculation of the moments of the particle counts, and (c) explicit expressions for mean coalescence times in multi-person random walks. These possibilities are illustrated by applications to Ehrenfest chains, the Hoare and Rahman chain, Kimura's continuous-time chain for DNA evolution, a light bulb chain, and random walks on some specific graphs.
Approximate probabilities for runs and patterns in i.i.d. and Markov-dependent multistate trials
Authors: Fu James C. , Johnson Brad C.
Published: April 2009

Let Xn(Λ) be the number of nonoverlapping occurrences of a simple pattern Λ in a sequence of independent and identically distributed (i.i.d.) multistate trials. For fixed k, the exact tail probability P{Xn (∧) < k} is difficult to compute and tends to 0 exponentially as n → ∞. In this paper we use the finite Markov chain imbedding technique and standard matrix theory results to obtain an approximation for this tail probability. The result is extended to compound patterns, Markov-dependent multistate trials, and overlapping occurrences of Λ. Numerical comparisons with Poisson and normal approximations are provided. Results indicate that the proposed approximations perform very well and do significantly better than the Poisson and normal approximations in many cases.
Neuropilin-mediated neural crest cell guidance is essential to organise sensory neurons into segmented dorsal root ganglia
Authors: Schwarz Quenten , Maden Charlotte H. , Davidson Kathryn , Ruhrberg Christiana
Published: April 2009

The peripheral nervous system (PNS) of higher vertebrates is segmented to align the spinal nerve roots with the vertebrae. This co-patterning is set up during embryogenesis, when vertebrae develop from the sclerotome layer of the metameric somites, and PNS neurons and glia differentiate from neural crest cells (NCCs) that preferentially migrate into the anterior sclerotome halves. Previous analyses of mice deficient in the class 3 semaphorin (SEMA3)receptors neuropilin (NRP) 1 or 2 raised the possibility that each controlled a distinct aspect of trunk NCC migration. We now demonstrate that both pathways act sequentially in distinct NCC subpopulations and thereby cooperate to enforce segmental NCC migration. Specifically, SEMA3A/NRP1 signalling first directs one population of NCCs from the intersomitic path into the sclerotome,and SEMA3F/NRP2 signalling acts subsequently to restrict a second population to the anterior half of the sclerotome. NCC exclusion from either the posterior sclerotome or the intersomitic boundary is sufficient to enforce the separation of neighbouring NCC streams and the segregation of sensory NCC progeny into metameric dorsal root ganglia (DRG). By contrast, the combined loss of both guidance pathways leads to ectopic invasion of the intersomitic furrows and posterior sclerotome halves, disrupting metameric NCC streaming and DRG segmentation.
A Comparison of Electricity Market Designs in Networks
Authors: Ehrenmann Andreas , Neuhoff Karsten
Published: April 2009

In Europe, two market designs are discussed for electricity trade and transmission. We argue that their performance in the presence of market power can be represented by two models from the literature. In contrast to examples for simple two-node networks, we show that in more complex networks a general ranking of both designs is not possible. Hence, computational models are required to evaluate the designs for realistic parameter assumptions. We extend existing formulations of both models to represent them as equilibrium problems with equilibrium constraints (EPEC) with equivalent representation of demand, fringe generation, and strategic generators. In a numerical simulation for the Northwestern European network, the integrated market design performs better. This difference illustrates the impact of small assumptions on the outcome of strategic models.
Modeling Implicit Collusion Using Coevolution
Authors: Anderson E. J. , Cau T. D. H.
Published: April 2009

Many oligopolies operate as a repeated game. In such circumstances, it can be expected that profit-maximising participants may engage in implicit collusion to profitably increase spot market prices. This paper models the emergence of such implicit collusion in a stylised market model using a coevolutionary approach. Players bid supply functions made up of a finite number of linear pieces. Each player uses a genetic algorithm to find state-based strategies depending on the price and demand in the last period and the predicted demand in the next period. We consider a symmetric duopoly and demonstrate that collusive behaviour can be learned even when there is very limited information available to the participants. Moreover, we show a type of implicit collusive behaviour that occurs even though the system does not settle into a stable equilibrium. We use a wholesale electricity market, in which supply function bids are typical, as a motivating example throughout this paper.
Optimal Policy for a Multiechelon Inventory System with Batch Ordering and Fixed Replenishment Intervals
Authors: Chao Xiuli , Zhou Sean X.
Published: April 2009

In many production/distribution systems, materials flow in fixed lot sizes (e.g., in full truckloads or full containers) and under regular schedules (e.g., delivery every week). In this paper, we study a multiechelon serial system with batch ordering and fixed replenishment intervals. We derive the optimal inventory control policy, provide a distribution-function solution for its optimal control parameters, and present an efficient algorithm for computing those parameters. Further, we show that the optimal expected system cost is minimized when the ordering times for all stages are synchronized. In contrast to the known approach in the literature that develops a lower bound for the average cost of a given period for the classical serial system, we develop a lower bound for the average total cost over an appropriately defined cycle and then construct a policy that reaches the lower bound. We also discuss its extension to the nonlinear shortage cost case (i.e., the nonlinear cost case). This paper generalizes several recent results on the analysis of multiechelon systems.
Utility of the Rosenberg Self-Esteem Scale
Authors: Davis Clare , Kellett Stephen , Beail Nigel
Published: April 2009

The Rosenberg Self-Esteem Scale (RSES) continues to be used to purportedly measure self-esteem of people with intellectual disabilities, despite the lack of sound evidence concerning its validity and reliability when employed with this population. The psychometric foundations of the RSES were analyzed here with a sample of 219 participants with intellectual disabilities. The factor analytic methods employed revealed two factors (Self-Worth and Self-Criticism) and more specific problems with RSES Items 5 and 8. Overall, this scale showed only moderate temporal and moderate internal reliability and poor aspects of criterion validity. Results are discussed with reference to either developing a new measure of self-esteem or redesigning and simplifying the RSES in order to increase its initial face validity in intellectual disability samples.
Depression in Adults With Mild Intellectual Disability: Role of Stress, Attributions, and Coping
Authors: Hartley Sigan L. , MacLean William E.
Published: April 2009

The experience of stressful social interactions, negative causal attributions, and the use of maladaptive coping efforts help maintain depression over time in the general population. We investigated whether a similar experience occurs among adults with mild intellectual disability. We compared the frequency and stress impact of such interactions, identified causal attributions for these interactions, and determined the coping strategies of 47 depressed and 47 nondepressed adults with mild intellectual disability matched on subject characteristics. The depressed group reported a higher frequency and stress impact of stressful social interactions, more negative attribution style, and more avoidant and less active coping strategies did than the nondepressed group. Findings have implications for theory building and development of psychotherapies to treat depression.
Correlation between Cooling Curves Obtained with a Silver Probe and Quenching Properties of 5140 Steel Bars
Authors: Wang R. S. , Wang Y. , Su L. P.
Published: April 2009

A computational method for the prediction of cooling curves at the center of a steel bar using experimentally measured cooling time-temperature data obtained from a cylindrical silver probe was developed based on nonsteady state heat conduction equations. This method involves: (1) the calculation of the critical size of the steel bar which is defined as the smallest size where no film boiling occurs, and (2) initial state of cooling of the steel bar in the quenchant, and the critical heat transfer coefficient of the quenching medium during nucleate boiling. This method was successfully used to: calculate the cooling curves at different locations within a 5140 steel bar which was quenched in three different quenching media, the hardness distribution, and French’s n and C values. The calculated data were validated against experimentally measured data. Using this method, it was shown that the critical heat transfer coefficient between the quenching medium and the steel bar is less than the critical heat transfer coefficient between the quenching medium and the silver probe. A logarithmic relationship between these two coefficients was established which can be used to simplify the calculations.
A Sixteenth-Century Catalog of Prohibited Music
Authors: Crook David
Published: April 2009

In 1575 the Jesuit general in Rome issued an ordinance governing the use of music in the order's rapidly expanding network of colleges. Motets, masses, hymns, "and other pious compositions" were to be retained; indecent and "vain" music was to be burned. Sixteen years later the Jesuits' provincial administrator in Bavaria drew up a set of supplemental instructions, to which was appended a catalog of prohibited music as well as a complementary list of approved compositions (D-Mbs Clm 9237). Verbal texts treating drunkenness and erotic love account for the majority of banned pieces, but in some cases—a setting of the first verse of Psalm 137 by Orlando di Lasso, for example—the sound and style of the music led to its prohibition.

Although intended for all colleges within the Jesuits' Upper German province, this catalog apparently derives solely from a review of the music collection of Munich's college on the occasion of its move in 1591 to a magnificent new building financed by the duke of Bavaria. Like the architecture and curriculum of the college, the music catalog reflected Bavaria's new understanding of its role as principal post-Tridentine defender of the true faith. And, like the formal confessions of faith, catechisms, and service books promulgated by Europe's Churches during the late sixteenth century, Bavaria's catalog of prohibited music gave expression to an ideology of difference and exclusion that lies at the very heart of post-Reformation Christianity.
Music After All
Authors: Currie James
Published: April 2009

For musicologists in the postmodern academy, the notion of context wields great force, both as a hermeneutic tool and as a meeting ground for a set of political beliefs that enable scholars to justify the meaning and relevance of their work. Primarily, this ideology is constituted by identity politics, the politics of difference and alterity, and the politics of locality and particularity. While acknowledging that musicological acts of cultural and historical contextualization per se are powerful means of illuminating cultural products, this essay nevertheless seeks, in its first half, to raise a set of questions regarding the efficacy of the accompanying political ideology within the pervasively unstable and dialectically totalized world of the early twenty-first century. Drawing extensively on the writings of the Slovenian cultural critic and theorist Slavoj Žižek and the French philosopher Alain Badiou, I argue that increasingly any localized context must be understood to be cut across by a kind of traumatic universalism that is, predominantly, economic in orientation.

The second part of the essay, however, turns in a different direction and argues that the route out of musicology's present political contradictions may lie not so much in the project of attempting once more to synthesize musicological and political practices into one, but rather through affirming the import of two (both musicology and politics, and music and politics). Through recourse to three theoretical discourses (into Heidegger, Hegel, and aspects of the Marxist tradition), the essay revisits the notion of musical autonomy, rescripting it—through an extensive analogy with dance—into a site where something unknown might manifest itself. Although it is acknowledged that this kind of site, strategically placed, might function effectively politically, it is nevertheless asserted that it is of sufficient import, in and of itself, to be preserved and nurtured, and that musicology in the academy is one of the privileged locations for where that might happen.
Jean-Jacques Rousseau's "unité de mélodie"
Authors: Waeber Jacqueline
Published: April 2009

Introduced by Jean-Jacques Rousseau in his Letter on French music (1753), "unité de mélodie" has commonly been understood as a technical rule asserting the primacy of melody over all the other musical parameters. It is the key concept of Rousseau's musical thought. Yet studies on eighteenth-century formulations of musical unity have paid only scant attention to Rousseau's discussions of it, explaining its presence in his œœuvre as a symptom of the growing influence of the style galant in France. Drawing on Rousseau's autobiographical and theoretical writings, this essay investigates the genesis of the "unité de mélodie," beginning with its rhetorical roots and the influence of Friedrich-Melchior Grimm's notion of the musical "contresens." But Rousseau's own autobiography is also key to understanding his intellectual approach to music. I argue that the "unité de mélodie" originated well before the years 1752–53, and that it is inextricably linked with Rousseau's preoccupation with writing and musical notation, a preoccupation motivated by his search for musical texts that would allow for direct comprehension, whether through listening or through score reading. Finally, in the concept of "unité de mélodie," we can see how Rousseau made a seminal contribution to late eighteenth-century French theoretical discourses on musical periodicity and on the importance of melody in establishing form.
Lipid peroxidation, assessed with BODIPY-C11, increases after cryopreservation of stallion spermatozoa, is stallion-dependent and is related to apoptotic-like changes
Authors: Ortega Ferrusola C , González Fernández L , Morrell J M , Salazar Sandoval C , Macías García B , Rodríguez-Martinez H , Tapia J A , Peña F J
Published: April 2009

Lipid peroxidation (LPO) of stallion spermatozoa was assessed in fresh semen and in samples of the same ejaculates after freezing and thawing. Particular attention was paid to individual differences in the susceptibility to LPO and its possible relationship with freezability. Innate levels of LPO were very low in fresh spermatozoa but increased after thawing, a change that was largely stallion-dependent. The level of LPO in fresh spermatozoa was not correlated with that of the thawed spermatozoa. Negative correlations existed between LPO and intact membranes post-thaw (r=−0.789,P<0.001), and also between LPO and spermatozoa with high mitochondrial membrane potential (Δψm) post-thaw (r=−0.689,P<0.001). LPO was also highly and significantly correlated with caspase activity. The correlation between caspase activity in ethidium positive cells and LPO wasr=0.772,P<0.001. This LPO is unlikely to represent,per se, a sign of cryopreservation-induced injury, but it is apparently capable of triggering ‘apoptotic-like changes’ that could result in the sub-lethal cryodamage often seen among surviving spermatozoa.
Telomeric RNAs Mark Sex Chromosomes in Stem Cells
Authors: Zhang Li-Feng , Ogawa Yuya , Ahn Janice Y , Namekawa Satoshi H , Silva Susana S , Lee Jeannie T
Published: April 2009

Telomeric regions are known to be transcribed in several organisms. Although originally reported to be transcribed from all chromosomes with enrichment near the inactive X of female cells, we show that telomeric RNAs in fact are enriched on both sex chromosomes of the mouse in a developmentally specific manner. In female stem cells, both active Xs are marked by the RNAs. In male stem cells, both the X and the Y accumulate telomeric RNA. Distribution of telomeric RNAs changes during cell differentiation, after which they associate only with the heterochromatic sex chromosomes of each sex. FISH mapping suggests that accumulated telomeric RNAs localize at the distal telomeric end. Interestingly, telomeric expression changes in cancer and during cellular stress. Furthermore, RNA accumulation increases in Dicer-deficient stem cells, suggesting direct or indirect links to RNAi. We propose that telomeric RNAs are tied to cell differentiation and may be used to mark pluripotency and disease.
A Genetic Screen for Suppressors of a Mutated 5′ Splice Site Identifies Factors Associated With Later Steps of Spliceosome Assembly
Authors: Dassah MaryAnn , Patzek Sophie , Hunt Valerie M , Medina Pedro E , Zahler Alan M
Published: April 2009

Many alleles of human disease genes have mutations within splicing consensus sequences that activate cryptic splice sites. In Caenorhabditis elegans, the unc-73(e936) allele has a G-to-U mutation at the first base of the intron downstream of exon 15, which results in an uncoordinated phenotype. This mutation triggers cryptic splicing at the −1 and +23 positions and retains some residual splicing at the mutated wild-type (wt) position. We previously demonstrated that a mutation in sup-39, a U1 snRNA gene, suppresses e936 by increasing splicing at the wt splice site. We report here the results of a suppressor screen in which we identify three proteins that function in cryptic splice site choice. Loss-of-function mutations in the nonessential splicing factor smu-2 suppress e936 uncoordination through changes in splicing. SMU-2 binds SMU-1, and smu-1(RNAi) also leads to suppression of e936. A dominant mutation in the conserved C-terminal domain of the C. elegans homolog of the human tri-snRNP 27K protein, which we have named SNRP-27, suppresses e936 uncoordination through changes in splicing. We propose that SMU-2, SMU-1, and SNRP-27 contribute to the fidelity of splice site choice after the initial identification of 5′ splice sites by U1 snRNP.
Teljes sternumdehiscentia miatt alkalmazott lemezes osteosynthesis (Titanium Sternal Fixation System® Synthes®) első magyarországi alkalmazásar
Authors: Hartyánszky István , Veres Gábor , Hüttl Tivadar , Moravcsik Endre , Kayser Sándor , Daróczi László , Vida Kata , Gálffy Ildikó , Szudi László , Szabolcs Zoltán
Published: April 2009

Absztrakt

A szívműtéteket követő mély sternomediastinitis gyakorisága 0,5–5% közötti, melynek mortalitása akár az 50%-ot is elérheti. A szerzők egy 67 éves nőbeteg esetén keresztül számolnak be szívműtétet követően kialakult súlyos sternumdehiscentia kezelésében alkalmazott lemezes osteosynthesis első magyarországi alkalmazásáról. Az ortopéd és traumatológiai sebészetben már régóta ismert módszer alkalmazása ezen betegcsoportban lehetővé teszi az anatómiai repositiót és a csontok maximális nyugalomba helyezését. A Titanium Sternal Fixation® Synthes® rendszer akár teljes vagy részleges sternumhiányok, darabos törések esetén is gyorsan és hatékonyan eredményezheti a betegek gyógyulását.
Prevention and managment possibilities of erectile dysfunction after radical prostatectomy
Authors: Riesz Péter , Rusz András , Szűcs Miklós , Majoros Attila , Nyírády Péter , Keszthelyi Attila , Szűcs Miklós , Mavrogenis Stelios , Filkor Gábor , Pánovics József , Romics Imre
Published: April 2009

Radical prostatectomy is the curative surgical management of organ confined prostate cancer. Erectile dysfunction may follow surgery as the most common complication decreasing the quality of life of the patient. Thanks to spreading PSA screening probabilty increases to detect prostate cancer in its early stage and so the expected number of surgery is increasing, too. Higher number of operation as well as surgery more frequently performed in younger age calls the attention to the importance of erectile dysfunction and its management. Nowadays the physiology of erectile dysfunction due to radical prostatectomy has been revealed, and as a consequence, the nerve sparing surgery for its prevention is already known. The paper presents the different kind of possible invasive and non-invasive treatments of erectile dysfunction, and surveys their history and effectiveness. The erectile function of patients who underwent radical prostatectomy between 1998 and 2007 at the Department of Urology and Urooncological Centre was assessed by IIEF- and MMM questionnaire and letters with questions of habit of medicine taking. The results showe that 59% of patients who require sexual life are capable of it spontaneously or with medical management.
Growth, Survival, and Habitat Use of Naturally Reared and Hatchery Steelhead Fry in Streams: Effects of an Enriched Hatchery Rearing Environment
Authors: Tatara Christopher P. , Riley Stephen C. , Scheurer Julie A.
Published: April 2009

After hatchery‐reared salmonids are released into the wild, their survival and performance are frequently lower than those of wild conspecifics. Additionally, negative effects of hatchery fish on wild fish are cited as factors affecting the recovery of salmonid populations. Alternative hatchery rearing environments and release practices have been proposed to mitigate both problems. We investigated the postrelease growth, survival, habitat use, and spatial distribution of hatchery steelhead Oncorhynchus mykiss fry reared in conventional and enriched environments and compared their performance with that of naturally reared steelhead fry from the same parent population in two streams. Average instantaneous growth rates differed between streams but not among the three rearing groups. The survival of naturally reared fry was significantly greater than that of both types of hatchery fry (relative survival = 0.33) but did not differ between the conventional and enriched environments. Naturally reared fry grew and survived equally well regardless of the type of hatchery fry with which they were stocked. Supplementation increased fry population size in all stream sections but produced hatchery‐biased populations. Steelhead fry preferred pool habitat within stream sections, but pool use was affected by an interaction between rearing environment and stream. Hatchery fry had more clumped spatial distributions than naturally reared fry, which were affected by a significant interaction between rearing type and stream. Hatchery rearing type and stream had no effect on the spatial distribution of naturally reared fry. We conclude that (1) hatchery steelhead fry released in streams grow as well as naturally reared fry but do not survive as well, (2) enriched hatchery environments do not improve postrelease growth or survival, and (3) upon release, fry raised in enriched hatchery environments affect the growth and survival of naturally reared fry in much the same way as fry reared in conventional hatchery environments.
17β-Estradiol inhibits 11β-hydroxysteroid dehydrogenase type 1 activity in rodent adipocytes
Authors: Tagawa Noriko , Yuda Ryosuke , Kubota Sayaka , Wakabayashi Midori , Yamaguchi Yuko , Kiyonaga Daisuke , Mori Natsuko , Minamitani Erika , Masuzaki Hiroaki , Kobayashi Yoshiharu
Published: April 2009

17β-Estradiol (E2) serves as an anti-obesity steroid; however, the mechanism underlying this effect has not been fully clarified. The effect of E2 on adipocytes opposes that of glucocorticoids, which potentiate adipogenesis and anabolic lipid metabolism. The key to the intracellular activation of glucocorticoid in adipocytes is 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1), which catalyses the production of active glucocorticoids (cortisol in humans and corticosterone in rodents) from inactive 11-keto steroids (cortisone in humans and 11-dehydrocorticosterone in rodents). Using differentiated 3T3-L1 adipocytes, we showed that E2 inhibited 11β-HSD1 activity. Estrogen receptor (ER) antagonists, ICI-182 780 and tamoxifen, failed to reverse this inhibition. A significant inhibitory effect of E2 on 11β-HSD1 activity was observed within 5–10 min. Furthermore, acetylation or α-epimerization of 17-hydroxy group of E2 attenuated the inhibitory effect on 11β-HSD1. These results indicate that the inhibition of 11β-HSD1 by E2 depends on neither an ER-dependent route, transcriptional pathway nor non-specific fashion. Hexose-6-phosphate dehydrogenase, which provides the cofactor NADPH for full activation of 11β-HSD1, was unaffected by E2. A kinetic study revealed that E2 acted as a non-competitive inhibitor of 11β-HSD1. The inhibitory effect of E2 on 11β-HSD1 was reproduced in adipocytes isolated from rat mesenteric fat depots. This is the first demonstration that E2 inhibits 11β-HSD1, thereby providing a novel insight into the anti-obesity mechanism of estrogen.
Collaborative working in highways major maintenance projects
Authors: Ansell M. , Evans R. , Holmes M. , Price A. , Pasquire C.
Published: April 2009

Over the last decade, there has been a growing emphasis on collaborations and partnering in the construction industry. This has been embraced in the UK highways maintenance sector, with partnering promoted by the client, leading to the formation of alliances and partnering frameworks. One of these is the construction management framework (CMF), the preferred method of procurement for major maintenance projects in the Highways Agency’s areas 9 and 10. This paper compares two road and structure renewals schemes carried out using the CMF. The first scheme was carried out in 2004 as one of the first of its type to be undertaken by the CMF; the second was a similar project carried out in 2006. Documentation of the two projects was reviewed to identify the benefits that were gained through working in collaboration, and if there was an improvement in performance as the framework became more established. The research considered key performance indicators, including cost and time predictability measures, respect for people surveys, innovations and lessons learned discussed at the time of the projects, and instructions for changes to works information. Data collected from both schemes show improvements in measurement and culture fostered by the CMF, and the advantages of the processes used are illustrated.
Collaboration in planning sustainable developments
Authors: Jackson J. I.
Published: April 2009

The urban-fringe development at Upton, Northampton is shown to illustrate the implementation of current best practice in community planning and design. The development includes principles of sustainable development and has provided an important case study for environmental monitoring and research. A key issue for the research group was to understand how the concepts of sustainable development were understood and transposed from a stakeholder consultation process to initial plans and design code. Major players were involved in taking innovative and conceptual ideas and charged with transferring these ideas into reality. These people were interviewed and this paper presents the narrative of their perceptions and enabling factors that allow people from a diverse range of disciplines to collaborate and contribute to an overall vision. This paper evaluates these interviews and discusses the role of partnership development, collaboration, transdisciplinarity and willingness to take a leap into uncharted urban planning territory.
The University of Minnesota School of Nursing: A Generation Ahead
Authors: Disch Joanne
Published: April 2009

In the first decade of the twentieth century, a unique experiment in education was begun, fostered, and brought through all the trials of disbelief and indifference to a high level of success. The School of Nursing at the University of Minnesota was the first training center of its kind to be sponsored, anywhere in the world, by an institution of higher learning (Board of Regents, 1908).
Evaluation of poly(ethylene-co-vinyl acetate-co-carbon monoxide) and polydimethylsiloxane for equilibrium sampling of polar organic contaminants in water
Authors: Magnér Jörgen A , Alsberg Tomas E. , Broman Dag
Published: April 2009

Abstract-The aim of the present study was to develop a passive a bsorptive equilibrium sampler that would enable the determination of the concentrations of polar organic compound (POC) in water more efficiently than existing techniques. To this end, a novel plastic material, poly(ethylene-co-vinyl acetate-co-carbon monoxide) (PEVAC), was evaluated and the results were compared with an existing silicone-based passive absorptive equilibrium device. Seven compounds (imidacloprid, carbendazim, metoprolol, atrazin, carbamazepine, diazinon, and chlorpyrifos), a mixture of pharmaceuticals, and pesticides with a logarithmic octanol-water partition coefficient ranging from 0.2 to 4.77 were selected as model substances for the experiments. The results showed that six of the seven selected POCs reached distribution equilibrium within 4 d in the two materials tested. A linear relation with a regression coefficient of more than 0.8906 between the established logarithmic absorbent-water partition coefficient and the calculated logarithmic dissociation partition coefficient of the selected compounds in the two polymers was observed. The correlation between these two coefficients was within one order of magnitude for the compounds that reached equilibrium in the two polymers, which demonstrates that both materials are suitable for mimicking biological uptake of POCs. The PEVAC material showed an enhanced sorption for all selected compounds compared to the silicone material and up to five times higher enrichment for the most polar compound. Fluorescence analysis of the sampler cross-section, following the uptake of fluoranthene, and proof that the sorption was independent of surface area variations demonstrated that the PEVAC polymer possessed absorptive rather than adsorptive enrichment of organic compounds.
Seed production of two meadow fescue cultivars differing in growth habit
Authors: MÄKELÄ P. , KOUSA M.
Published: April 2009

Meadow fescue (Festuca pratensis Huds.) is grown widely in the Nordic countries in forage grass mixtures. Locally adapted cultivars are preferred for establishment of mixed swards. Meadow fescue seed yield is determined by seed weight, the number of panicle bearing tillers, size of panicles and the number of fertile florets. We aimed to determine the differences in components of seed yield in two different meadow fescue cultivars differing in forage quality; Kalevi, released in 1979, and Fure, released in 1999. Biomass accumulation was monitored, numbers of fertile and sterile florets, and seeds were counted, and the forage quality was analysed. Seed quality was also analysed. Fure was leafier and accumulated more vegetative biomass than Kalevi. Kalevi had significantly more panicles than Fure, although Fure compensated for the lower number of panicles with increased panicle size. There were no differences in number of sterile and aborted florets between cultivars. Based on the results it seems that these two meadow fescue cultivars have a completely different strategy in seed production even though the final seed yield was not markedly different. It is apparent that meadow fescues have good ability to compensate among the components of seed yield. Long-term field experiments should be conducted to investigate the interactions between plant stand ecology, seed production and cultivation technology.;
Cyclic Fatigue of Different Nickel-Titanium Rotary Instruments: A Comparative Study
Authors: Testarelli L. , Grande N.M , Plotino G , Lendini M , Pongione G , Paolis G. De , Rizzo F , Milana V , Gambarini G
Published: April 2009

Since the introduction of nickel-titanium alloy to endodontics, there have been many changes in instrument design, but no significant improvements in the raw material properties, or enhancements in the manufacturing process. Recently, a new method to produce nickel-titanium rotary (NTR) instruments has been developed, in an attempt to obtain instruments that are more flexible and resistant to fatigue. NTR instruments produced using the process of twisting (TF, SybronEndo, Orange, CA) were compared to NTR instruments from different manufacturers produced by a traditional grinding process. The aim of the study was to investigate whether cyclic fatigue resistance is increased for TF NTR files. Tests were performed with a cyclic fatigue device that evaluated cycles to failure of rotary instruments inside curved artificial canals. Results indicated that size 06-25 TF instruments showed a significant increase (P< .05). In the mean number of cycles to failurewhen compared to the other tested 06-25 NTR. Hence, it can be concluded that size 06-25 TF NTR instruments were found to be significantly more resistant to fatigue than those produced with the traditional grinding process.
Extrusion of Endodontic Filling Materials: Medico-Legal Aspects. Two Cases
Authors: Santoro Valeria , Lozito Piercarlo , Donno Antonio De , Grassi Felice Roberto , Introna Francesco
Published: April 2009

The Authors describe two cases of alleged malpractice due to overfilling. The aim of this article is to underline some medico-legal aspects regarding the quantity of extruded material which may be considered acceptable and the consequent damage to the patient.

Two cases are presented here: In the first case, the dentist’s liability is clear due to excessive extrusion of endodontic material beyond the apical region combined with incomplete obturation of the canals. In the second case however, because two different dentists were involved, establishing the connection of causality between their work and the damage reported by the patient was not easy. This situation makes it difficult to establish the limits of potential responsibility, coupled with the complete absence of radiographic signs of periapical rarefaction and the small quantities of material beyond the apex. From a medico-legal point of view, a dentist may be held responsible for compensation and financial expenses of a patient for restoration of damage resulting from a dental procedure.

Italian guidelines offer no indications as to when overfilling should be considered the result of a procedural error, or if it fits within the range labelled as “acceptable” and this gap offers extremely subjective interpretations of legal consultants. So, it would therefore be useful to adopt more precise qualitative/dimensional parameters, keeping in mind that the guidelines offer therapeutic recommendations and are not rigid protocols.
Colon and Breast Anti-cancer Effects of Peptide Hydrolysates Derived from Rice Bran
Authors: Kannan Arvind , Hettiarachchy Navam , Narayan Satya
Published: April 2009

Rice bran is an economical, under-utilized co-product of rough rice milling. The objective of this study was to produce rice-bran peptides and investigate for anti-cancer activity. Protein hydrolysates were prepared by treating heat stabilized defatted rice-bran with food grade Alcalase enzyme, followed by treatment with simulated gastric and intestinal juices to obtain resistant peptides. Resistant peptides were fractionated into >50, 10-50, 5-10, and <5 kDa sizes, freeze dried, and evaluated for inhibitory and cytotoxicity activities on human colon (HCT-116) and breast (HTB-26) cancer cell lines. The results showed that <5 kDa fraction of rice-bran is a potent anti-cancer agent. The cytotoxicity of the fraction to both cancer cell types was more pronounced after the treatment with 500 µg/mL. The IC50 of the peptide fraction was approximately 750 µg/mL. These results indicate that the <5 kDa peptide fraction separated from rice bran protein hydrolysate has a potent anti-tumor activity for colon cancer cells. The peptide fractions that demonstrate anti-cancer activities have the potential for use as functional food ingredients for health benefits.
Organizational Change in Local Governments: The Impact of the Danish Local Government Reform
Authors: Baekgaard Martin
Published: April 2009

The article explores organizational structures in public organizations that are the results of amalgamations of two or more public organizations. Focusing on the Danish Local Government Reform implemented in 2007, the main questions are whether the new municipalities have decided to organize themselves differently than their predecessors, and whether the interests of centrally placed actors affect such a decision. Data on the political and administrative organization of all Danish municipalities in 2005 and 2007 show that the number of organizational units grew considerably more in the 66 new municipalities than it did in the 32 municipalities whose territory was not changed because of the reform. The analyses show that the increased number of organizational units can in part be explained by new municipal tasks and increased workload due to the new structural conditions. An important part of the increase, however, was caused neither by task related, nor by structural changes. Alternatively, the increase may be explained by political norms stating that all relevant interests should be given a top post in the new organizations.
The Construction of ‘Toddler’ in Early Childhood Pedagogy
Authors: Løkken Gunvor
Published: April 2009

The theoretical construction in this article rests on one constitutive pillar of seeing the toddler within the view of Merleau-Pontyan philosophy, combined with a second pillar of empirical toddler peer studies, from both of which an emerging toddler ‘style’ of socializing is read. ‘Style’ in this analytical context should be viewed as a phenomenological and hermeneutical construct. To enable the construction of ‘toddler’ in early childhood pedagogy to stand, the necessary third pillar deals with the inquiry of a pedagogical notion proper to this context. Such a notion must accord with the view that the toddler of our time actively contributes to the construction of him-or herself, as well as of the persons, objects, surroundings and culture of the world in which he or she lives, and with which he or she interacts. To be at all noteworthy in the changeable plurality of post-or late modern times, this notion must be both transformative and transformable. A look at the Bildung tradition of pedagogy, whilst considering postmodern ‘hypertransformation’ as well as the ancient root of pedagogy, forwards a conclusion that changeability goes side by side with durability, as does uniqueness with universality.
The Complexity of Bodily Events through an Ethnographer's Gaze: Focusing on the Youngest Children in Preschool
Authors: Rossholt Nina
Published: April 2009

This article discusses theoretical, methodological and analytical strategies for researching the material subject. The discussion relates to discursive practices in a preschool setting with children of one and two years of age, where the material subject includes both bodily and discursive practices. Using critical ethnography research, the author follows studies of lived life connected to body/place relations. When the body is the main focus in writing, it may be possible to understand how children at this age relate to each other in complex and multiple ways. From observations, the author deconstructs two events. These relate to how actions and movements are situated not only in language, but also in bodily practices amongst children. The body is a site for negotiation with pleasure, pain, other bodies, space and visibility. Working with bodily practices transforms how power is performed, and whose interests are silenced, marginalized or excluded. From a Foucauldian perspective, this is about knowledge/power relations. From a Deleuzean perspective, body/place relations transform how we may see, feel and think otherwise.
Initial Impressions: Reflections of Pre-Service Educators
Authors: Sweigard Thomas L.
Published: April 2009

Preservice early childhood educators responded in daily reflection journals on their field experience in local elementary classrooms. These journal entries were categorized according to the frequency of the responses. The focus of the study became the nature of the initial impressions that these preservice educators had of their cooperating teachers. We know that first impressions many times are very important. Much can be learned about how these cooperating teachers handled the first few minutes of interaction with the preservice educators.
Supporting the Supporters of Novice Teachers: An Analysis of Mentors' Needs from Twelve European Countries Presented from an English Perspective
Authors: Jones Marion
Published: April 2009

This article is located within the wider European context of teacher development and is specifically concerned with the needs of those supporting novice teachers during the early stages in their professional career. Currently, induction systems across Europe are largely fragmented, locally based and with little transference of best practice. There is therefore a perceived need to develop a common focus on the specific needs of those supporting new entrants to the profession particularly with regard to improving the quality of teaching and learning, but also in terms of improving teacher recruitment and retention. This article reports the results of a needs analysis exercise which was conducted as part of a Comenius project (Teacher Induction: Supporting the Supporters of Novice Teachers in Europe). Data collection by means of semi-structured questionnaires involved a total of 282 practising teachers from 12 European member states and was supplemented by follow-up interviews. The aim was to identify key themes around which common support strategies for mentors assisting new teachers in their professional learning could be developed. These emerged as: the aspect of nurture; quality assurance and accountability; reflective practice; collaborative learning communities; and interpersonal and communicative competence. The data generated revealed a high diversity in terms of respondents' perceptions of the multiple aspects of the mentoring role and the tensions inherent and reflected the idiosyncratic nature of the various educational contexts. As such the findings highlight the need for developing a common focus on mentor training and development for those supporting novice teachers and promote the values and principles underpinning a democratic professionalism.
Towards a Formalised Teacher Induction System: The Macau Experience
Authors: Vong Sou-Kuan , Wong Matilda
Published: April 2009

This article discusses the importance of teacher induction not only for sustaining teacher retention and reducing attrition, but also for supporting beginning teachers, helping them develop professionally as they progress within the profession and enhancing effective teaching and learning. While acknowledging the importance of teacher induction, the article examines the development of teacher education in Macau and attempts to analyse the reasons for the absence of a formal teacher induction system at present. It discusses how informal developments in pre-service teacher preparation that have taken place could be considered as a sort of ‘gradual induction’ to help Macau teachers assimilate into the profession and how these developments could be facilitated for the future. The article concludes by suggesting that, to ensure quality and on-going professional development, a formal teacher induction system or programme in the form of a university and school partnership is desirable.
Teacher Induction in Australia: A Sample of What's Really Happening
Authors: Hudson Sue , Beutel Denise , Hudson Peter
Published: April 2009

Retention rates and stress levels of beginning teachers are of concern. Well-planned induction programs can assist beginning teachers to make the transition successfully into the profession, which may increase retention rates. This qualitative, year-long study aims to explore and describe the induction experiences of eight beginning teachers as they negotiated their first year of teaching. Data gathered through interviews and emails indicated that these teachers required further development on: catering for individual differences, assessing in terms of outcomes, relating to parents, relating to the wider community, and understanding school policies; however, relating to students and understanding legal responsibilities and duty of care were not issues. At the conclusion of their first year only one beginning teacher was assisted by a mentor (veteran teacher) on whole-school programming, and planning for improving teaching with opportunities to visit other classrooms. This was also the only beginning teacher who received a reduced workload in order to meet with the mentor to discuss pedagogical developments. The inadequate support provided to beginning teachers in this study highlights the need for principals and school staff to reassess induction processes, which includes providing time, funding, mentoring support and clear guidelines for a quality induction program.
The Induction of Beginning Teachers in Scotland and Hong Kong: Getting it Right?
Authors: Draper Janet , Forrester Victor
Published: April 2009

Where the continuing professional development (CPD) process is being increasingly articulated and circumscribed by policy and central specification, the initial year of teaching may significantly shape career-long expectations of CPD. This article contrasts the early experiences of beginning secondary teachers in Scotland and Hong Kong and the emergent model that highlights a tension between the systems' support structures and individual autonomy. To resolve this impasse, the authors conclude by arguing for a different model that places as synonymous new teachers' induction, CPD and approaches to becoming autonomous.