bluuebunny/crossref_metadata_2025 huggingface dataset:
Parent voice: knowledge, values and viewpoint
Authors: Lumby Jacky
Published: November 2007

National policy increasingly stresses the importance of parents' engagement in education. However, tensions and struggle for control between parents and teachers is a common research finding. This article identifies a number of reasons why parents' views on curriculum, pedagogy and the purpose of schooling are commonly seen as of less relevance or legitimacy than those of teachers. The views of parents of children participating in vocational courses offered through two 14—19 Pathfinder partnerships are interrogated. The cogency of parents' views and the differences in the values of parents and staff emerge. It is suggested that if parents' voice is silenced, it is likely to be for reasons other than their capacity to enter into a debate on curriculum and pedagogy.
Light touch critical friendship
Authors: Swaffield Sue
Published: November 2007

Critical friendship is a flexible form of support for school colleagues and one that is increasingly being applied to different contexts, including the New Relationship with Schools and School Improvement Partners. The ESRC/TLRP `Learning How to Learn' (LHTL) project was interested in, among other things, the scaling up of innovation, and incorporated light touch critical friendship in its design. This article explores the role of the critical friend in LHTL, the factors that helped or hindered, and concludes that light touch critical friendship is dependent upon three interrelated conditions: trust on the part of the school colleague, engagement and commitment by both parties, and the critical friend's knowledge of the school. School Improvement Partners have limited contact with schools through `a single conversation', and are described in government documentation as `critical friends'. However, it is argued that this is an erroneous use of the term, likely to have negative consequences.
To set or not to set; is that the question?
Authors: Boyd Brian
Published: November 2007

This article provides an evaluation of the rationale for, and impact of, setting with English classes in the second year of secondary school in one Scottish authority. The Council's education department has a long-standing policy of mixed-ability classes in English for the first two years of secondary school (S2). A number of schools approached the department requesting that the policy be relaxed to enable them to `set' by prior attainment in S2, while retaining mixed-ability organization in S1. In fact, some had, unilaterally, done so and were looking for post hoc permission. The authority commissioned the author to work with the schools, to evaluate the reasons advanced for the desired change, to assess the impact of the change or proposed change on pupils and teachers, and to report back. Visits took place to four of the five schools, classes were observed, teachers and pupils, school-generated evidence considered and a report written. This article discusses the context within which the debate was taking place; the rationale offered for setting and mixed ability; the issues emerging from the visits to schools; and the implications for decision-making at authority and school level.
The `smaller' the school, the better? the Smaller Learning Communities (SLC) program in US high schools
Authors: Lee Moosung , Friedrich Tom
Published: November 2007

Given the widening achievement gap between whites and students of color in US schools, Small Learning Communities have emerged as a reform measure claimed to boost achievement in general and among racial minorities. This article examines this claim by reviewing the major policy documents and literature on SLC and analyzing SLC using Frank's (1972) policy assessment criteria. The SLC program was found to be theoretically grounded in social capital theory, to be feasible politically and financially given strong federal and private foundations' support, and to have strong ethical merit given its aims of raising achievement, closing the racial achievement gap and personalizing learning. Analysis of multiple standardized data sets on 193 SLC schools showed that despite modest achievement gains, the racial gap was found to still be wide, although SLC schools located in large cities where students of color predominated made consistent gains, and Hispanic students showed significant yearly gains. Implications for research and policy are reviewed.
The BBC and television fame in the 1950s
Authors: Holmes Su
Published: November 2007

This article aims to contribute to historical knowledge about television's relations with fame, while simultaneously exploring the conceptual tools used to study this field. With this in mind, this article examines two case studies from the 1950s: the BBC's popular serial The Grove Family and the interview-in-depth programme Face to Face . A key aim is to draw out the different meanings which circulated around television's relations with fame. Television has always constructed its own `personalities' (the Groves), while simultaneously circulating personae `outside' of their primary public or media roles ( Face to Face). The article suggests that returning to this earlier context raises important questions. Where do these later conceptual claims of television fame locate their historical roots? To what extent were the debates about television fame a continuation of those surrounding radio? And to what degree are concepts such as `ordinariness' historical?
Audiences and everyday aesthetics
Authors: Hesmondhalgh David
Published: November 2007

The first part of this article outlines a dilemma in cultural studies and sociology of culture regarding the politics of aesthetics. This concerns whether discourse about the evaluation of symbolic forms serves to reinforce power relations and maintain divisions between people and communities, or whether evaluation can serve as a basis for greater commonality. One way of at least beginning to address this issue is to attend to the 'everyday aesthetics' of media audiences, exemplified here in the ordinary evaluative discourse of music users. The second part of the article reports on interview research about musical tastes and values. It analyses these interviews for evidence of the ways in which evaluative statements might involve making connections with others, or alternatively how they may act as barriers to social connectivity or community. How and to what extent might ordinary musical evaluation be thought of as part of potential aesthetic public spheres?
Qualifications to the Rottenberg Invariance Theorem
Authors: Krautmann Anthony C.
Published: November 2007

A total of 50 years after Simon Rottenberg's article appeared in the Journal of Political Economy, his seminal article continues to be one of the most cited studies in the field of sports economics. Although his article discusses such central concepts as the Uncertainty of Outcome Hypothesis and how territorial rights are the underlying source of monopoly power, he is perhaps best known for his Invariance Theorem. Here Rottenberg states that the allocation of talent in a sports league is invariant to the ownership of property rights. This Strong interpretation of invariance, which is widely held by the profession, is predicated on a number of fairly demanding conditions. In this article, the author explores a number of these conditions, which must apply in order that Strong invariance holds. These conditions include the Daly and Moore externality problem, the critical role of transaction costs, and the impact of player preferences. Although the author respectfully acknowledges Rottenberg's Invariance Theorem for its insightfulness and elegant prowess, he simply wishes to point out how restrictive the conditions are that underlie Strong invariance.
Celebrity Misbehavior in the NBA
Authors: Kendall Todd D.
Published: November 2007

I compare and contrast theories of why NBA players misbehave on the court, then test them empirically. I find evidence that earnings are positively correlated with misbehavior and that both absolute and relative salary matter. For instance, a player who is highest paid on his team misbehaves roughly 7% more than one who is second-highest paid, even at the same salary level. This relative effect I interpret as due to lack of good substitutes for top players. I also find some evidence that personal preferences may be important in understanding misbehavior, but no evidence that immaturity or peer effects are important determinants of misbehavior in the NBA.
A Constructive Comment on “Rematches in Boxing and Other Sporting Events”
Authors: Sanders Shane
Published: November 2007

In the following note, I derive part of the boxing contest model developed by Amegashie and Kutsoati (2005), correct an error in its solution, and show that their main result may extend to a larger set of boxing contests. Specifically, there may well be a class of boxing matches in which two competitors will put forth greater aggregate efforts in response to a greater likelihood of a rematch, regardless of the degree to which their abilities differ. The revised solution is constructive in the sense that it builds upon the main result of Amegashie and Kutsoati.
Testing Rosen's Sequential Elimination Tournament Model
Authors: Gilsdorf Keith F. , Sukhatme Vasant A.
Published: November 2007

The authors use an extensive and unique data set from the men's professional tennis circuit to test Rosen's sequential elimination style tournament model. Specifically, they investigate what effect an increase in prize money differentials between rounds has on the stronger player's probability of winning the match. This involves estimating a standard probit model utilizing data from 2,632 individual matches over 68 tournaments during the 2001 men's professional tennis circuit. The results of the study support predictions associated with Rosen's match play tournament model. Increases in prize money differentials have a positive, statistically significant effect on the stronger player's probability of winning the match.
A Contingent Valuation of the 2012 London Olympic Games
Authors: Walton Harry , Longo Alberto , Dawson Peter
Published: November 2007

Major sporting events such as the Olympics are usually assessed in terms of economic impacts. Recently, policy makers have begun to place greater emphasis on possible intangible effects (such as civic pride, legacy of sporting facilities) associated with such events. To date, little work has been carried out on quantifying these effects in a meaningful way. This study uses contingent valuation methodology to assess the value of the proposed 2012 London Olympic Games. The survey is carried out on the provincial city of Bath, approximately 2 hours west of London. Conducting the survey outside of London is justified on the basis that the organizers of London 2012 have emphasized the value of the event to the United Kingdom as a whole. The results suggest that positive intangible effects are associated with the event and residents outside of London are willing to pay toward funding.
Efficacy and safety of a new-class hemostatic drug candidate, AV513, in dogs with hemophilia A
Authors: Prasad Srinivasa , Lillicrap David , Labelle Andrea , Knappe Sabine , Keller Tracy , Burnett Erin , Powell Sandra , Johnson Kirk W.
Published: November 2007

AV513 is a select fucoidan, a sulfated polysaccharide of botanical origin. It inhibits tissue factor pathway inhibitor (TFPI) activity and accelerates clotting of human hemophilia A and B plasma. In prior work, subcutaneous administration of AV513 to mice with hemophilia A improved hemostasis. The current studies were designed to evaluate potential efficacy and safety in dogs with hemophilia A (hemophilia A dogs) with minimally increased hemostasis after adenoassociated viral-FVIII gene transfer and in treatment-naive severe hemophilia A dogs. AV513 administered subcutaneously to low-FVIII dogs for multiple weeks improved hemostasis as exhibited in thromboelastography (TEG) and cuticle bleeding time (CBT) tests. Moreover, AV513 administered orally to AAV-FVIII dogs and treatment-naive severe hemophilia A dogs for a multiweek dose-escalating period yielded correction to normal ranges in both TEG and CBT end points at 5 to 15 mg/kg and 15 to 20 mg/kg dose levels, respectively. In all 3 separate studies, throughout their duration, AV513 was well tolerated by the dogs without any adverse events. Additional pharmacologic characterization of AV513 included intravenous pharmacokinetic analysis in rats. In summary, the combination of safety and efficacy in 2 global tests of hemostasis in the hemophilia A dog model indicate that further evaluation of AV513 as a hemostatic agent in hemophilia A patients is warranted.
Idiopathic pulmonary fibrosis: multiple causes and multiple mechanisms?
Authors: Maher T. M. , Wells A. U. , Laurent G. J.
Published: November 2007

Idiopathic pulmonary fibrosis (IPF) is a devastating condition that carries a prognosis worse than that of many cancers.

A recent classification of the idiopathic interstitial pneumonias has redefined the diagnostic criteria necessary to determine a diagnosis of IPF. The present authors believe that this redefinition is incorrect, relying as it does on subtle histological differences for the definition of separate disease categories.

A further issue affecting IPF research is the polarisation of views around two competing pathogenetic hypotheses. One argues for the primacy of inflammation as the trigger that initiates fibrosis, and the other proposes that fibrosis arises as a consequence of chronic epithelial injury and failure of repair due to aberrant epithelial–mesenchymal interactions. The present authors believe that this schism is hampering understanding of IPF and skewing research priorities.

It is argued here, instead, that abnormalities in multiple pathways involved in wound healing and inflammation lead to the development of idiopathic pulmonary fibrosis, and it is suggested that a new rationale for clinical classification and pathogenesis may be more productive in driving the search for novel therapies in the future.
Preliminary nanopore cheminformatics analysis of aptamer-target binding strength
Authors: Thomson Karen , Amin Iftekhar , Morales Eric , Winters-Hilt Stephen
Published: November 2007

Background

Aptamers are nucleic acids selected for their ability to bind to molecules of interest and may provide the basis for a whole new class of medicines. If the aptamer is simply a dsDNA molecule with a ssDNA overhang (a "sticky" end) then the segment of ssDNA that complements that overhang provides a known binding target with binding strength adjustable according to length of overhang.

Results

Two bifunctional aptamers are examined using a nanopore detector. They are chosen to provide sensitive, highly modulated, blockade signals with their captured ends, while their un-captured regions are designed to have binding moieties for complementary ssDNA targets. The bifunctional aptamers are duplex DNA on their channel-captured portion, and single-stranded DNA on their portion with binding ability. For short ssDNA, the binding is merely to the complementary strand of DNA, which is what is studied here – for 5-base and 6-base overhangs.

Conclusion

A preliminary statistical analysis using hidden Markov models (HMMs) indicates a clear change in the blockade pattern upon binding by the single captured aptamer. This is also consistent with the hypothesis that significant conformational changes occur during the annealing binding event. In further work the objective is to simply extend this ssDNA portion to be a well-studied ~80 base ssDNA aptamer, joined to the same bifunctional aptamer molecular platform.
Robust clustering in high dimensional data using statistical depths
Authors: Ding Yuanyuan , Dang Xin , Peng Hanxiang , Wilkins Dawn
Published: November 2007

Background

Mean-based clustering algorithms such as bisecting k-means generally lack robustness. Although componentwise median is a more robust alternative, it can be a poor center representative for high dimensional data. We need a new algorithm that is robust and works well in high dimensional data sets e.g. gene expression data.

Results

Here we propose a new robust divisive clustering algorithm, the bisecting k-spatialMedian, based on the statistical spatial depth. A new subcluster selection rule, Relative Average Depth, is also introduced. We demonstrate that the proposed clustering algorithm outperforms the componentwise-median-based bisecting k-median algorithm for high dimension and low sample size (HDLSS) data via applications of the algorithms on two real HDLSS gene expression data sets. When further applied on noisy real data sets, the proposed algorithm compares favorably in terms of robustness with the componentwise-median-based bisecting k-median algorithm.

Conclusion

Statistical data depths provide an alternative way to find the "center" of multivariate data sets and are useful and robust for clustering.
Prognostic impact of clinicopathologic parameters in stage II/III breast cancer treated with neoadjuvant docetaxel and doxorubicin chemotherapy: paradoxical features of the triple negative breast cancer
Authors: Keam Bhumsuk , Im Seock-Ah , Kim Hee-Jun , Oh Do-Youn , Kim Jee Hyun , Lee Se-Hoon , Chie Eui Kyu , Han Wonshik , Kim Dong-Wan , Moon Woo Kyung , Kim Tae-You , Park In Ae , Noh Dong-Young , Heo Dae Seog , Ha Sung Whan , Bang Yung-Jue
Published: November 2007

Background

Prognostic factors in locally advanced breast cancer treated with neoadjuvant chemotherapy differ from those of early breast cancer. The purpose of this study was to identify the clinical significance of potential predictive and prognostic factors in breast cancer patients treated by neoadjuvant chemotherapy.

Methods

A total of 145 stage II and III breast cancer patients received neoadjuvant docetaxel/doxorubicin chemotherapy were enrolled in this study. We examined the clinical and biological factors (ER, PR, p53, c-erbB2, bcl-2, and Ki-67) by immunohistochemistry. We analyzed clinical outcome and their correlation with clinicopathologic parameters.

Results

Among the clinicopathologic parameters investigated, none of the marker was correlated with response rate (RR) except triple negative phenotype. Patients with triple negative phenotype showed higher RR (83.0% in triple negative vs. 62.2% in non-triple negative, p = 0.012) and pathologic complete RR (17.0% in triple negative vs. 3.1% in non-triple negative, p = 0.005). However, relapse free survival (RFS) and overall survival (OS) were significantly shorter in triple negative breast cancer patients (p < 0.001, p = 0.021, respectively). Low histologic grade, positive hormone receptors, positive bcl-2 and low level of Ki-67 were associated with prolonged RFS. In addition, positive ER and positive bcl-2 were associated with prolonged OS. In our homogeneous patient population, initial clinical stage reflects RFS and OS more precisely than pathologic stage. In multivariate analysis, initial clinical stage was the only significant independent prognostic factor to impact on OS (hazard ratio 3.597, p = 0.044).

Conclusion

Several molecular markers provided useful predictive and prognostic information in stage II and III breast cancer patients treated with neoadjuvant docetaxel/doxorubicin chemotherapy. Triple negative phenotype was associated with shorter survival, even though it was associated with a higher response rate to neoadjuvant chemotherapy.
Exposure of bakery and pastry apprentices to airborne flour dust using PM2.5 and PM10personal samplers
Authors: Mounier-Geyssant Estelle , Barthélemy Jean-François , Mouchot Lory , Paris Christophe , Zmirou-Navier Denis
Published: November 2007

Background

This study describes exposure levels of bakery and pastry apprentices to flour dust, a known risk factor of occupational asthma.

Methods

Questionnaires on work activity were completed by 286 students. Among them, 34 performed a series of two personal exposure measurements using a PM2.5 and PM10 personal sampler during a complete work shift, one during a cold ("winter") period, and the other during a hot ("summer") period.

Results

Bakery apprentices experience greater average PM2.5 and PM10 exposures than pastry apprentices (p < 0.006). Exposure values for both particulate fractions are greater in winter (average PM10 values among bakers = 1.10 mg.m-3 [standard deviation: 0.83]) than in summer (0.63 mg.m-3 [0.36]). While complying with current European occupational limit values, these exposures exceed the ACGIH recommendations set to prevent sensitization to flour dust (0.5 mg.m-3). Over half the facilities had no ventilation system.

Conclusion

Young bakery apprentices incur substantial exposure to known airways allergens, a situation that might elicit early induction of airways inflammation.
Comparison of glucosamine sulfate and a polyherbal supplement for the relief of osteoarthritis of the knee: a randomized controlled trial [ISRCTN25438351]
Authors: Mehta Komal , Gala Jayesh , Bhasale Surendra , Naik Sattayasheel , Modak Millind , Thakur Harshad , Deo Nivedita , Miller Mark JS
Published: November 2007

Background

The efficacy and safety of a dietary supplement derived from South American botanicals was compared to glucosamine sulfate in osteoarthritis subjects in a Mumbai-based multi-center, randomized, double-blind study.

Methods

Subjects (n = 95) were screened and randomized to receive glucosamine sulfate (n = 47, 1500 mg/day) or reparagen (n = 48, 1800 mg/day), a polyherbal consisting of 300 mg of vincaria (Uncaria guianensis) and 1500 mg of RNI 249 (Lepidium meyenii) administered orally, twice daily. Primary efficacy variable was response rate based on a 20% improvement in WOMAC pain scores. Additional outcomes were WOMAC scores for pain, stiffness and function, visual analog score (VAS) for pain, with assessments at 1, 2, 4, 6 and 8 weeks. Tolerability, investigator and subject global assessments and rescue medication consumption (paracetamol) were measured together with safety assessments including vital signs and laboratory based assays.

Results

Subject randomization was effective: age, gender and disease status distribution was similar in both groups. The response rates (20% reduction in WOMAC pain) were substantial for both glucosamine (89%) and reparagen (94%) and supported by investigator and subject assessments. Using related criteria response rates to reparagen were favorable when compared to glucosamine. Compared to baseline both treatments showed significant benefits in WOMAC and VAS outcomes within one week (P < 0.05), with a similar, progressive improvement over the course of the 8 week treatment protocol (45–62% reduction in WOMAC or VAS scores). Tolerability was excellent, no serious adverse events were noted and safety parameters were unchanged. Rescue medication use was significantly lower in the reparagen group (p < 0.01) at each assessment period. Serum IGF-1 levels were unaltered by treatments.

Conclusion

Both reparagen and glucosamine sulfate produced substantial improvements in pain, stiffness and function in subjects with osteoarthritis. Response rates were high and the safety profile was excellent, with significantly less rescue medication use with reparagen. Reparagen represents a new natural productive alternative in the management of joint health.

Trial registration

Current Controlled Trials ISRCTN25438351.
The Iconoclasm of the Stage and the Return of the Body
Authors: Castellucci Romeo
Published: November 2007

Translated by Gloria Pastorino
Stochastic patterning in the mouse pre-implantation embryo
Authors: Dietrich Jens-Erik , Hiiragi Takashi
Published: November 2007

Mouse pre-implantation development gives rise to the blastocyst, which is made up of at least three distinct cell types: the trophectoderm (TE) that surrounds a cavity, and an inner cell mass (ICM) comprising the primitive endoderm (PE) and epiblast (EPI). However, the underlying mechanisms involved in patterning the cleavage-stage embryo are still unresolved. By analyzing the distribution of the transcription factors Oct4 (Pou5f1), Cdx2 and Nanog at precisely defined stages in pre-implantation development, we were able to identify critical events leading to the divergence of TE, EPI and PE lineages. We found that Oct4 is present in all cells until late blastocyst, gradually disappearing from the TE thereafter. The expression patterns of both Cdx2 and Nanog exhibit two specific phases, culminating in their restriction to TE and EPI, respectively. In the first phase, starting after compaction, blastomeres show highly variable Cdx2 and Nanog protein levels. Importantly, the variability in Nanog levels is independent of position within the morula,whereas Cdx2 variability may originate from asymmetric cell divisions at the 8-cell stage in a non-stereotypic way. Furthermore, there is initially no reciprocal relationship between Cdx2 and Oct4 or between Cdx2 and Nanog protein levels. In the second phase, a definite pattern is established,possibly by a sorting process that accommodates intrinsic and extrinsic cues. Based on these results, we propose a model in which early embryonic mouse patterning includes stochastic processes, consistent with the highly regulative capacity of the embryo. This may represent a feature unique to early mammalian development.
Kremen is required for neural crest induction inXenopusand promotes LRP6-mediated Wnt signaling
Authors: Hassler Christine , Cruciat Cristina-Maria , Huang Ya-Lin , Kuriyama Sei , Mayor Roberto , Niehrs Christof
Published: November 2007

Kremen 1 and 2 (Krm1/2) are transmembrane receptors for Wnt antagonists of the Dickkopf (Dkk) family and function by inhibiting the Wnt co-receptors LRP5/6. Here we show that Krm2 functions independently from Dkks during neural crest (NC) induction in Xenopus. Krm2 is co-expressed with, and regulated by, canonical Wnts. Krm2 is differentially expressed in the NC, and morpholino-mediated Krm2 knockdown inhibits NC induction, which is mimicked by LRP6 depletion. Conversely, krm2 overexpression induces ectopic NC. Kremens bind to LRP6, promote its cell-surface localization and stimulate LRP6 signaling. Furthermore, Krm2 knockdown specifically reduces LRP6 protein levels in NC explants. The results indicate that in the absence of Dkks, Kremens activate Wnt/β-catenin signaling through LRP6.
Senseless functions as a molecular switch for color photoreceptor differentiation inDrosophila
Authors: Xie Baotong , Charlton-Perkins Mark , McDonald Elizabeth , Gebelein Brian , Cook Tiffany
Published: November 2007

A major question in development is how different specialized cell types arise from a common progenitor. In the adult Drosophila compound eye,color discrimination is achieved by UV-, blue- and green-sensitive photoreceptors (PRs). These different PR subsets arise from neuronal precursors called R7 and R8 cells. Recent studies have demonstrated that R7-based UV-sensitive PRs require the repression of R8-based blue/green-sensitive PR characteristics to properly develop. This repression is mediated by the transcription factor Prospero (Pros). Here, we report that Senseless (Sens), a Drosophila ortholog of the vertebrate Gfi1 transcription factor, plays an opposing role to Pros by both negatively regulating R7-based features and positively enforcing R8-based features during terminal differentiation. In addition, we demonstrate that Pros and Sens function together with the transcription factor Orthodenticle (Otd) to oppositely regulate R7 and R8 PR Rhodopsin gene expression in vitro. These data show that sens, previously shown to be essential for neuronal specification, also controls differentiation of specific neuronal subtypes in the retina. Interestingly, Pros has recently been shown to function as a tumor suppressor, whereas Gfi1 is a well-characterized oncogene. Thus, we propose that sens/pros antagonism is important for regulating many biological processes.
Highly Selective Extraction of TcO4−, ReO4−, and MoO42− by the New Ligand, 2,2′-(Methylimino)bis(N,N-Dioctylacetamide) (MIDOA)
Authors: Sasaki Yuji , Kitatsuji Yoshihiro , Kimura Takaumi
Published: November 2007

Highly selective extraction of oxonium anions can be achieved by the new ligand, 2,2′-(methylimino)bis(N,N-dioctylacetamide) (MIDOA). MIDOA has a high solubility in n-dodecane, any types of diluents can be employed for the solvent extraction. The extraction using MIDOA was performed under the condition, HNO3 and n-dodecane, considering the chemical process of high-level radioactive liquid waste. It was obvious that the oxonium anions, like TcO4−, ReO4−, Cr2O72−, MoO42−, and WO42−, are extracted, and the distribution ratios (D) decrease with increase of HNO3 concentration.
Simultaneous Spectrophotometric Determination of Ozone and Hydrogen Peroxide
Authors: Kitsuka Kenta , Mohammad Ahmad M , Awad Mohamed Ismail , Kaneda Kazuhiro , Ikematsu Mineo , Iseki Masahiro , Mushiake Katsuhiko , Ohsaka Takeo
Published: November 2007

A simple, rapid, and highly selective spectrophotometric method for the simultaneous analysis of ozone (O3) and hydrogen peroxide (H2O2) is proposed. On the basis of the large difference in the reaction rates of O3 and H2O2 with I−, a changed absorbance corresponding to the reactions of the two species with I− was observed. This method enables a highly selective simultaneous analysis of O3 and H2O2 in their coexistence.
Measuring the Electronic Decay Constant of Alkanedithiols by Electrochemical Impedance Spectroscopy
Authors: Zhang Yumei , Ma Qingwei , Zhang Hongming , Zhu Guoyi
Published: November 2007

Several methods have been used for the measurement of the electronic decay constant (β) of organic molecules. However, each of them has some disadvantages. For the first time, electrochemical impedance spectroscopy (EIS) was used to obtain the β value by measuring the tunneling resistance through alkanedithiols. The tunneling resistance through alkanedithiols increases exponentially with the molecular length in terms of the mechanism of coherent nonresonant tunneling. β was 0.51±0.01 per carbon.
Oxidation of Secondary Benzylic Alcohols to Ketones by Activated Carbon–Molecular Oxygen System
Authors: Sano Yuki , Tanaka Takanori , Hayashi Masahiko
Published: November 2007

A variety of benzylic alcohols were oxidized to the corresponding carbonyl compounds selectively in the presence of activated carbon under molecular oxygen atmosphere. This process does not require any metal oxides, thus this is environmentally friendly and economical.
Rapid and Deep Nitridation of Silica MCM-41 without Loss of Hexagonal Pore Structure
Authors: Ishizu Ken-ichi , Hayashi Fumitaka , Iwamoto Masakazu
Published: November 2007

The nitridation of mesoporous silica MCM-41 with ammonia was carried out by using a plug flow-type reactor. The degree of nitridation was dependent on the amount of NH3 supplied. Mesoporous silicon oxynitride containing 34 wt % of nitrogen could be prepared at 1273 K for 8 h, and the hexagonal mesoporous structure was maintained.
Benzylation of α-Diimine Ligands Bound to Zirconium and Hafnium. A New Convenient Route to Olefin Polymerization Catalysts
Authors: Mashima Kazushi , Ohnishi Ryuji , Yamagata Tsuneaki , Tsurugi Hayato
Published: November 2007

Reactions of M(CH2Ph)4 (M = Zr and Hf) with α-diimine ligands 1 at −78 °C selectively afford tribenzyl amido–imino complexes of zirconium 4 and hafnium 5, whose treatment with B(C6F5)3 gave the corresponding cationic dibenzyl complexes 6 and 7 capable of polymerizing 1-hexene.
Copper(I)- and Gold(I)-catalyzed Synthesis of 2,4-Disubstituted Quinoline Derivatives from N-Aryl-2-propynylamines
Authors: Kuninobu Yoichiro , Inoue Yuichi , Takai Kazuhiko
Published: November 2007

2,4-Disubstituted quinoline derivatives were obtained from N-aryl-2-propynylamines catalyzed by copper(I) and gold(I) complexes. The quinoline derivatives could also be obtained by the reaction of N-arylaldimines with terminal acetylenes via the formation of N-aryl-2-propynylamines.
Improving Web-Catalog Design for Easy Product Search
Authors: Chiang I. Robert , Nunez Manuel A.
Published: November 2007

Building intuitive web sites is important for online businesses as positive experiences toward the virtual storefront could translate to customer goodwill and repeat visits. Streamlining web-site navigation is further motivated by the availability of comprehensive site-visit traces such as shopping carts and click-stream logs. We incorporate such sales and browsing patterns for the autonomous design of web catalogs by reducing the expected click count it takes to find related items. We first model catalog design as a task of placing items onto catalog pages, leading to a quadratic assignment formulation. For a more extensive redesign, such as when the number and location of links on each page are also decision variables, we propose a two-stage optimization procedure to ensure that click-count reduction is not achieved at the cost of excessive page cluttering. Our analysis reveals that an optimized catalog is robust against shifts in browsing behavior and that simplistic interfaces are preferred for users at either end of the experience spectrum. Using genetic algorithms, we find catalog designs that significantly outperform those found with a traditional greedy heuristic.
Primal-Dual Variable Neighborhood Search for the Simple Plant-Location Problem
Authors: Hansen Pierre , Brimberg Jack , Urošević Dragan , Mladenović Nenad
Published: November 2007

The variable neighborhood search metaheuristic is applied to the primal simple plant-location problem and to a reduced dual obtained by exploiting the complementary slackness conditions. This leads to (i) heuristic resolution of (metric) instances with uniform fixed costs, up to n=15,000 users, and m=n potential locations for facilities with an error not exceeding 0.04%; (ii) exact solution of such instances with up to m=n=7,000; and (iii) exact solutions of instances with variable fixed costs and up to m=n=15,000.
Asynchronous Cooperative Local Search for the Office-Space-Allocation Problem
Authors: Landa-Silva Dario , Burke Edmund K.
Published: November 2007

We investigate cooperative local search to improve upon known results of the office-space-allocation problem in universities and other organizations. A number of entities (e.g., research students, staff, etc.) must be allocated into a set of rooms so that the physical space is utilized as efficiently as possible while satisfying a number of hard and soft constraints. We develop an asynchronous cooperative local search approach in which a population of local search threads cooperate asynchronously to find better solutions. The approach incorporates a cooperation mechanism in which a pool of genes (parts of solutions) is shared to improve the global search strategy. Our implementation is single-processor and we show that asynchronous cooperative search is also advantageous in this case. We illustrate this by extending four single-solution metaheuristics (hill-climbing, simulated annealing, tabu search, and a hybrid metaheuristic) to population-based variants using our asynchronous cooperative mechanism. In each case, the population-based approach performs better than the single-solution one using comparable computation time. The asynchronous cooperative metaheuristics developed here improve upon known results for a number of test instances.
Rescheduling for Multiple New Orders
Authors: Hall Nicholas G. , Liu Zhixin , Potts Chris N.
Published: November 2007

Aset of original jobs has been scheduled on a single machine, but not processed, when a set of new jobs arrives. The decision maker needs to insert the new jobs into the existing schedule without excessively changing it. The objective is minimization of the maximum lateness of the jobs, subject to a customer service requirement modeled by a limit on the maximum time change of the original jobs. Because the schedule of the original jobs can be arbitrary, this problem models multiple disruptions from repeated new job arrivals. We show that this scheduling problem is intractable, even if no new jobs arrive. We describe several approximation algorithms and analyze their worst-case performance. Next, we develop a branch and bound algorithm that uses a variable neighborhood descent algorithm to obtain an initial upper bound, several dominance properties that we establish, and a lower bounding scheme based on a preemptive relaxation of the problem. The branch and bound algorithm solves 99.9% of randomly generated instances with up to 1,000 jobs within 60 CPU seconds. Our work demonstrates for the first time that optimization of large scale, intractable rescheduling problems is possible. More generally, it refocuses the literature on scheduling problems towards rescheduling issues.
Implementation of sorption hysteresis in multi-Fickian moisture transport
Authors: Lund Frandsen Henrik , Svensson Staffan
Published: November 2007

In the cellular structure of wood, bound-water diffusion and water-vapor diffusion interact via sorption in a complex moisture-transportation system. At low relative humidities, moisture transport may be modeled by a Fickian diffusion equation with a good approximation. At higher relative humidities, slow sorption and faster bound-water diffusion cause effects, which have been referred to as non-Fickian or anomalous, as they cannot be modeled by one Fickian diffusion equation. Previous research has demonstrated that a set of coupled diffusion equations, namely the multi-Fickian model, can represent this behavior. The multi-Fickian model describes the combined transport of bound water and vapor and their interaction through sorption. The bound-water concentration is also influenced by sorption hysteresis. In the worst case, sorption hysteresis may result in deviations of up to 30–35% in moisture content. Hence, for a precise moisture content computation, sorption hysteresis must be taken into account. The present paper explains the relation between sorption hysteresis and multi-Fickian moisture transport, and clarifies how models for the two phenomena are coupled. To illustrate the effects, a finite element simulation, which is based on the combined model, is presented.
Analysis of wood tissues by time-of-flight secondary ion mass spectrometry
Authors: Tokareva Elena N. , Pranovich Andrey V. , Fardim Pedro , Daniel Geoffrey , Holmbom Bjarne
Published: November 2007

The distribution of lignin, carbohydrates, and metal ions on the surface of spruce and aspen wood tissue sections was investigated by time-of-flight secondary ion mass spectrometry (ToF-SIMS). The distribution patterns of metals and lignin in ray cells, vessels, and fibres were different, whereas carbohydrates were uniformly distributed across the sections of all morphological regions. In spruce sapwood, Ca, Mg, Na, K, Fe locations was more pronounced in the bordered pit tori and inner layer of ray parenchyma cells. Little lignin was detected in these regions. In spruce heartwood, the degree of lignification was low on the surfaces of bordered pit tori; however, Na and K were not detected here. In compression wood from spruce, the locations of p-hydroxyphenyl and guaiacyl units was different in cell wall layers. In aspen sapwood, the main locations of Ca, Mg, Na, K were in lumina of longitudinal parenchyma cells and in pits between vessels and ray cells. Low-intensity signals of the secondary ions assigned to lignin were found in the same morphological regions.
Identifying Problems and Generating Recommendations for Enhancing Complex Systems: Applying the Abstraction Hierarchy Framework as an Analytical Tool
Authors: Xu Wei
Published: November 2007

Objective: This study adopts J. Rasmussen's (1985) abstraction hierarchy (AH) framework as an analytical tool to identify problems and pinpoint opportunities to enhance complex systems. Background: The process of identifying problems and generating recommendations for complex systems using conventional methods is usually conducted based on incompletely defined work requirements. As the complexity of systems rises, the sheer mass of data generated from these methods becomes unwieldy to manage in a coherent, systematic form for analysis. There is little known work on adopting a broader perspective to fill these gaps. Method: AH was used to analyze an aircraft-automation system in order to further identify breakdowns in pilot-automation interactions. Four steps follow: developing an AH model for the system, mapping the data generated by various methods onto the AH, identifying problems based on the mapped data, and presenting recommendations. Results: The breakdowns lay primarily with automation operations that were more goal directed. Identified root causes include incomplete knowledge content and ineffective knowledge structure in pilots' mental models, lack of effective higher-order functional domain information displayed in the interface, and lack of sufficient automation procedures for pilots to effectively cope with unfamiliar situations. Conclusion: The AH is a valuable analytical tool to systematically identify problems and suggest opportunities for enhancing complex systems. It helps further examine the automation awareness problems and identify improvement areas from a work domain perspective. Application: Applications include the identification of problems and generation of recommendations for complex systems as well as specific recommendations regarding pilot training, flight deck interfaces, and automation procedures.
Performance Enhancement in an Uninhabited Air Vehicle Task Using Psychophysiologically Determined Adaptive Aiding
Authors: Wilson Glenn F. , Russell Christopher A.
Published: November 2007

Objective: We show that psychophysiologically driven real-time adaptive aiding significantly enhances performance in a complex aviation task. Afurther goal was to assess the importance of individual operator capabilities when providing adaptive aiding. Background: Psychophysiological measures are useful for monitoring cognitive workload in laboratory and real-world settings. They can be recorded without intruding into task performance and can be analyzed in real time, making them candidates for providing operator functional state estimates. These estimates could be used to determine if and when system intervention should be provided to assist the operator to improve system performance. Methods: Adaptive automation was implemented while operators performed an uninhabited aerial vehicle task. Psychophysiological data were collected and an artificial neural network was used to detect periods of high and low mental workload in real time. The high-difficulty task levels used to initiate the adaptive automation were determined separately for each operator, and a group-derived mean difficulty level was also used. Results: Psychophysiologically determined aiding significantly improved performance when compared with the no-aiding conditions. Improvement was greater when adaptive aiding was provided based on individualized criteria rather than on group-derived criteria. The improvements were significantly greater than when the aiding was randomly provided. Conclusion: These results show that psychophysiologically determined operator functional state assessment in real time led to performance improvement when included in closed loop adaptive automation with a complex task. Application: Potential future applications of this research include enhanced workstations using adaptive aiding that would be driven by operator functional state.
Cough Once for Danger: Icons Versus Abstract Warnings as Informative Alerts in Civil Aviation
Authors: Perry Nathan C. , Stevens Catherine J. , Wiggins Mark W. , Howell Clare E.
Published: November 2007

Objective: An experiment investigated the efficacy of auditory icons as warning signals in an aviation context. Background: Iconic signals, such as a cough to signal dangerous levels of carbon monoxide, convey information about the nature of an incident and alert the operator that there is a problem, whereas signals that are arbitrarily associated with a critical incident provide relatively less information. Warning recognition speed and accuracy are likely to be influenced by modality of presentation (visual, auditory, auditory + visual) and task demand (low, high). Methods: The 172 participants completed a computer-based training session and test task that involved responding to abstract or iconic auditory (1 s), visual, or auditory + visual warnings associated with seven critical incidents while performing low- and high-demand concurrent tasks. Results: Significantly fewer training trials were required to learn iconic warnings than abstract warnings. An advantage for iconic warnings persisted into the test phase, evident most consistently as greater warning recognition accuracy. The effect was observed in both high- and low-demand conditions. Auditory abstract warnings, in particular, elicited slow reaction times and poor accuracy. Conclusion: Associations between a small number of meaningful environmental sounds and critical incidents can be learned with ease relative to more abstract associations, although training is required and response times are relatively slow. Application: Sets of distinctive auditory iconic warnings can be designed to alert and inform pilots about non-time-pressured events. Potential applications of language-neutral icons as informative warnings include civil, commercial, and defense aircraft.
Collaborative Training With a More Experienced Partner: Remediating Low Pretraining Self-Efficacy in Complex Skill Acquisition
Authors: Day Eric Anthony , Boatman Paul R. , Kowollik Vanessa , Espejo Jazmine , McEntire Lauren E. , Sherwin Rachel E.
Published: November 2007

Objective: This study examined the effectiveness of collaborative training for individuals with low pretraining self-efficacy versus individuals with high pretraining selfefficacy regarding the acquisition of a complex skill that involved strong cognitive and psychomotor demands. Background: Despite support for collaborative learning from the educational literature and the similarities between collaborative learning and interventions designed to remediate low self-efficacy, no research has addressed how selfefficacy and collaborative learning interact in contexts concerning complex skills and human-machine interactions. Method: One hundred fifty-five young male adults trained either individually or collaboratively with a more experienced partner on a complex computer task that simulated the demands of a dynamic aviation environment. Participants also completed a task-specific measure of self-efficacy before, during, and after training. Results: Collaborative training enhanced skill acquisition significantly more for individuals with low pretraining self-efficacy than for individuals with high pretraining self-efficacy. However, collaborative training did not bring the skill acquisition levels of those persons with low pretraining self-efficacy to the levels found for persons with high pretraining self-efficacy. Moreover, tests of mediation suggested that collaborative training may have enhanced appropriate skill development strategies without actually raising self-efficacy. Conclusion: Although collaborative training can facilitate the skill acquisition process for trainees with low self-efficacy, future research is needed that examines how the negative effects of low pretraining self-efficacy on complex skill acquisition can be more fully remediated. Application: The differential effects of collaborative training as a function of self-efficacy highlight the importance of person analysis and tailoring training to meet differing trainee needs.
A Bernstein result for entire F-minimal graphs
Authors: Winklmann Sven
Published: November 2007

We consider the nonparametric Euler–Lagrange equation which arises from an elliptic parametric functional with integrand
Neptunium(V) disproportionation and cation–cation interactions in TBP/kerosene solvent
Authors: Sarsfield Mark J. , Taylor Robin J. , Maher Chris J.
Published: November 2007

In 30% TBP/OK Np(V) is unstable and disproportionates to Np(IV) and Np(VI). Np(V) readily coordinates to Np(IV) in solution to form a “cation–cation” complex by bonding through an axial oxo group on Np(V). The rate of disproportionation in 30% TBP/OK is >500 times that in aqueous solution.