bluuebunny/crossref_metadata_2025 huggingface dataset:
High tunneling magnetoresistance in Fe/GaOx/Ga1−xMnxAs with metal/insulator/semiconductor structure
Authors: Saito H. , Yamamoto A. , Yuasa S. , Ando K.
Published: November 2008

We fabricated Fe/GaOx/Ga1−xMnxAs magnetic tunnel diodes that had a metal/insulator/semiconductor (MIS) structure. A tunneling magnetoresistance (TMR) ratio up to 58% was observed, which is the highest value yet reported in MIS-type TMR devices. This indicates that GaOx is an excellent tunnel-barrier material for spin-dependent transport between 3d-ferromagnetic metal and GaAs-based semiconductors.
Single shot measurement of the lifetime of a trapped electron in the gate dielectric of a high-k field effect transistor
Authors: Khan M. Ziaur Rahman , Hasko D. G. , Saifullah M. S. M. , Welland M. E.
Published: November 2008

The transient behavior of a trapped electron in the TiO2 sol-gel based gate dielectric layer of a silicon-on-insulator metal-oxide-semiconductor field effect transistor is investigated. Defects in this dielectric layer give rise to microwave resonances that are electrically detected via the channel current. The lifetime of the excited state is inferred from the quality factor of the resonance. A single shot measurement, carried out on the same resonance, is used to characterize the transient behavior and to directly measure the lifetime of the excited state. Possible applications of transient measurements on high-k dielectric layers are discussed.
Analysis of maize canopy development under water stress and incorporation into the ADEL-Maize model
Authors: Song Youhong , Birch Colin , Hanan Jim
Published: November 2008

Substantial progress in modelling crop architecture has been made under optimal watering conditions; however, crop production is often exposed to water stress. In this research, we develop methods for implementing the simulation of maize (Zea mays L.) canopy architectural development under water stress using data from a maize field trial in 2006–07. Data of leaf number, leaf and internode extension were collected using non-destructive and destructive sampling at 2–3 day intervals. Water stress reduced the extension rate of organs and, therefore, their final length, the reduction being greater as severity of water stress increased. The duration of extension of organs in most phytomers was not significantly affected by water stress. Also, the rate of extension during the linear phase responded linearly to fraction of extractable soil water. An existing 3-D architectural model ADEL-Maize was revised using relationships developed in this study to better incorporate effects of water stress on organ extension and production. Simulated canopy production under three water regimes was validated by comparing predicted final leaf and internode length, plant height and leaf area to independent observations. The analysis and simulation showed that maize organ extension and final length under water stress can be adequately represented by simple linear patterns that are easily integrated into models.
Pan-specific MHC class I predictors: a benchmark of HLA class I pan-specific prediction methods
Authors: Zhang Hao , Lundegaard Claus , Nielsen Morten
Published: November 2008

Motivation: MHC:peptide binding plays a central role in activating the immune surveillance. Computational approaches to determine T-cell epitopes restricted to any given major histocompatibility complex (MHC) molecule are of special practical value in the development of for instance vaccines with broad population coverage against emerging pathogens. Methods have recently been published that are able to predict peptide binding to any human MHC class I molecule. In contrast to conventional allele-specific methods, these methods do allow for extrapolation to uncharacterized MHC molecules. These pan-specific human lymphocyte antigen (HLA) predictors have not previously been compared using independent evaluation sets.

Result: A diverse set of quantitative peptide binding affinity measurements was collected from Immune Epitope database (IEDB), together with a large set of HLA class I ligands from the SYFPEITHI database. Based on these datasets, three different pan-specific HLA web-accessible predictors NetMHCpan, adaptive double threading (ADT) and kernel-based inter-allele peptide binding prediction system (KISS) were evaluated. The performance of the pan-specific predictors was also compared with a well performing allele-specific MHC class I predictor, NetMHC, as well as a consensus approach integrating the predictions from the NetMHC and NetMHCpan methods.

Conclusions: The benchmark demonstrated that pan-specific methods do provide accurate predictions also for previously uncharacterized MHC molecules. The NetMHCpan method trained to predict actual binding affinities was consistently top ranking both on quantitative (affinity) and binary (ligand) data. However, the KISS method trained to predict binary data was one of the best performing methods when benchmarked on binary data. Finally, a consensus method integrating predictions from the two best performing methods was shown to improve the prediction accuracy.

Contact:  mniel@cbs.dtu.dk

Supplementary information:  Supplementary data are available at Bioinformatics online.
Widespread balancing selection and pathogen-driven selection at blood group antigen genes
Authors: Fumagalli Matteo , Cagliani Rachele , Pozzoli Uberto , Riva Stefania , Comi Giacomo P. , Menozzi Giorgia , Bresolin Nereo , Sironi Manuela
Published: November 2008

Historically, allelic variations in blood group antigen (BGA) genes have been regarded as possible susceptibility factors for infectious diseases. Since host–pathogen interactions are major determinants in evolution, BGAs can be thought of as selection targets. In order to verify this hypothesis, we obtained an estimate of pathogen richness for geographic locations corresponding to 52 populations distributed worldwide; after correction for multiple tests and for variables different from selective forces, significant correlations with pathogen richness were obtained for multiple variants at 11 BGA loci out of 26. In line with this finding, we demonstrate that three BGA genes, namely CD55, CD151, and SLC14A1, have been subjected to balancing selection, a process, rare outside MHC genes, which maintains variability at a locus. Moreover, we identified a gene region immediately upstream the transcription start site of FUT2 which has undergone non-neutral evolution independently from the coding region. Finally, in the case of BSG, we describe the presence of a highly divergent haplotype clade and the possible reasons for its maintenance, including frequency-dependent balancing selection, are discussed. These data indicate that BGAs have been playing a central role in the host–pathogen arms race during human evolutionary history and no other gene category shows similar levels of widespread selection, with the only exception of loci involved in antigen recognition.
Tomato Ribonuclease LX with the Functional Endoplasmic Reticulum Retention Motif HDEF Is Expressed during Programmed Cell Death Processes, Including Xylem Differentiation, Germination, and Senescence
Authors: Lehmann Karin , Hause Bettina , Altmann Dorit , Köck Margret
Published: November 2008

We have studied the subcellular localization of the acid S-like ribonuclease (RNase) LX in tomato (Lycopersicon esculentum Mill.) cells using a combination of biochemical and immunological methods. It was found that the enzyme, unexpectedly excluded from highly purified vacuoles, accumulates in the endoplasmic reticulum. The evidence that RNase LX is a resident of the endoplasmic reticulum (ER) is supported by an independent approach showing that the C-terminal peptide HDEF of RNase LX acts as an alternative ER retention signal in plants. For functional testing, the cellular distribution of chimeric protein constructs based on a marker protein, Brazil nut (Bertholletia excelsa) 2S albumin, was analyzed immunochemically in transgenic tobacco (Nicotiana tabacum) plants. Here, we report that the peptide motif is necessary and sufficient to accumulate 2S albumin constructs of both vacuolar and extracellular final destinations in the ER. We have shown immunochemically that RNase LX is specifically expressed during endosperm mobilization and leaf and flower senescence. Using immunofluorescence, RNase LX protein was detected in immature tracheary elements, suggesting a function in xylem differentiation. These results support a physiological function of RNase LX in selective cell death processes that are also thought to involve programmed cell death. It is assumed that RNase LX accumulates in an ER-derived compartment and is released by membrane disruption into the cytoplasma of those cells that are intended to undergo autolysis. These processes are accompanied by degradation of cellular components supporting a metabolic recycling function of the intracellular RNase LX.
Cytosolic Glutamine Synthetase in Soybean Is Encoded by a Multigene Family, and the Members Are Regulated in an Organ-Specific and Developmental Manner
Authors: Morey Kevin J. , Ortega Jose Luis , Sengupta-Gopalan Champa
Published: November 2008

Gln synthetase (GS) is the key enzyme in N metabolism and it catalyzes the synthesis of Gln from glutamic acid, ATP, and NH4  +. There are two major isoforms of GS in plants, a cytosolic form (GS1) and a chloroplastic form (GS2). In leaves, GS2 functions to assimilate ammonia produced by nitrate reduction and photorespiration, and GS1 is the major isoform assimilating NH3produced by all other metabolic processes, including symbiotic N2 fixation in the nodules. GS1 is encoded by a small multigene family in soybean (Glycine max), and cDNA clones for the different members have been isolated. Based on sequence divergence in the 3′-untranslated region, three distinct classes of GS1 genes have been identified (α, β, and γ). Genomic Southern analysis and analysis of hybrid-select translation products suggest that each class has two distinct members. The α forms are the major isoforms in the cotyledons and young roots. The β forms, although constitutive in their expression pattern, are ammonia inducible and show high expression in N2-fixing nodules. The γ1 gene appears to be more nodule specific, whereas the γ2 gene member, although nodule enhanced, is also expressed in the cotyledons and flowers. The two members of the α and β class of GS1 genes show subtle differences in the expression pattern. Analysis of the promoter regions of the γ1 and γ2 genes show sequence conservation around the TATA box but complete divergence in the rest of the promoter region. We postulate that each member of the three GS1 gene classes may be derived from the two ancestral genomes from which the allotetraploid soybean was derived.
Inducers of Glycinebetaine Synthesis in Barley
Authors: Jagendorf André T. , Takabe Tetsuko
Published: November 2008

Glycinebetaine is an osmoprotectant accumulated by barley (Hordeum vulgare) plants in response to high levels of NaCl, drought, and cold stress. Using barley seedlings in hydroponic culture, we characterized additional inducers of glycinebetaine accumulation. These included other inorganic salts (KCl, MgCl2, LiCl, and Na2SO4), oxidants (H2O2 and cumene hydroperoxide), and organic compounds (abscisic acid, polymixin B, n-butanol, salicylic acid, and aspirin). Stress symptoms brought on by high NaCl and other inducers, and not necessarily correlated with glycinebetaine accumulation, include wilting, loss of chlorophyll, and increase in thiobarbituric acid reacting substances. For NaCl, Ca2+ions at 10 to 20 mm decrease these stress symptoms without diminishing, or even increasing, glycinebetaine induction. Abscisic acid induces glycinebetaine accumulation without causing any of the stress symptoms. NaCl, KCl, and H2O2 (but not other inducers) induce glycinebetaine at concentrations below those needed for the other stress symptoms. Mg2+ at 10 to 20 mm induces both stress symptoms and glycinebetaine, but only at low (0.2 mm) Ca2+. Although illumination is needed for optimal induction, a significant increase in the leaf glycinebetaine level is found in complete darkness, also.
Attenuation of Phosphate Starvation Responses by Phosphite in Arabidopsis
Authors: Ticconi Carla A. , Delatorre Carla A. , Abel Steffen
Published: November 2008

When inorganic phosphate is limiting, Arabidopsis has the facultative ability to metabolize exogenous nucleic acid substrates, which we utilized previously to identify insensitive phosphate starvation response mutants in a conditional genetic screen. In this study, we examined the effect of the phosphate analog, phosphite (Phi), on molecular and morphological responses to phosphate starvation. Phi significantly inhibited plant growth on phosphate-sufficient (2 mm) and nucleic acid-containing (2 mmphosphorus) media at concentrations higher than 2.5 mm. However, with respect to suppressing typical responses to phosphate limitation, Phi effects were very similar to those of phosphate. Phosphate starvation responses, which we examined and found to be almost identically affected by both anions, included changes in: (a) the root-to-shoot ratio; (b) root hair formation; (c) anthocyanin accumulation; (d) the activities of phosphate starvation-inducible nucleolytic enzymes, including ribonuclease, phosphodiesterase, and acid phosphatase; and (e) steady-state mRNA levels of phosphate starvation-inducible genes. It is important that induction of primary auxin response genes by indole-3-acetic acid in the presence of growth-inhibitory Phi concentrations suggests that Phi selectively inhibits phosphate starvation responses. Thus, the use of Phi may allow further dissection of phosphate signaling by genetic selection for constitutive phosphate starvation response mutants on media containing organophosphates as the only source of phosphorus.
GAMYB-like Genes, Flowering, and Gibberellin Signaling in Arabidopsis
Authors: Gocal Gregory F.W. , Sheldon Candice C. , Gubler Frank , Moritz Thomas , Bagnall David J. , MacMillan Colleen P. , Li Song F. , Parish Roger W. , Dennis Elizabeth S. , Weigel Detlef , King Rod W.
Published: November 2008

We have identified three Arabidopsis genes withGAMYB-like activity, AtMYB33,AtMYB65, and AtMYB101, which can substitute for barley (Hordeum vulgare) GAMYB in transactivating the barley α-amylase promoter. We have investigated the relationships between gibberellins (GAs), theseGAMYB-like genes, and petiole elongation and flowering of Arabidopsis. Within 1 to 2 d of transferring plants from short- to long-day photoperiods, growth rate and erectness of petioles increased, and there were morphological changes at the shoot apex associated with the transition to flowering. These responses were accompanied by accumulation of GAs in the petioles (GA1 by 11-fold and GA4 by 3-fold), and an increase in expression of AtMYB33 at the shoot apex. Inhibition of GA biosynthesis using paclobutrazol blocked the petiole elongation induced by long days. Causality was suggested by the finding that, with GA treatment, plants flowered in short days, AtMYB33expression increased at the shoot apex, and the petioles elongated and grew erect. That AtMYB33 may mediate a GA signaling role in flowering was supported by its ability to bind to a specific 8-bp sequence in the promoter of the floral meristem-identity gene, LEAFY, this same sequence being important in the GA response of theLEAFY promoter. One or more of theseAtMYB genes may also play a role in the root tip during germination and, later, in stem tissue. These findings extend our earlier studies of GA signaling in the Gramineae to include a dicot species, Arabidopsis, and indicate that GAMYB-like genes may mediate GA signaling in growth and flowering responses.
Nonselective Currents and Channels in Plasma Membranes of Protoplasts from Coats of Developing Seeds of Bean
Authors: Zhang Wen-Hao , Skerrett Martha , Walker N. Alan , Patrick John W. , Tyerman Stephen D.
Published: November 2008

In developing bean (Phaseolus vulgaris) seeds, phloem-imported nutrients move in the symplast from sieve elements to the ground parenchyma cells where they are transported across the plasma membrane into the seed apoplast. To study the mechanisms underlying this transport, channel currents in ground parenchyma protoplasts were characterized using patch clamp. A fast-activating outward current was found in all protoplasts, whereas a slowly activating outward current was observed in approximately 25% of protoplasts. The two currents had low selectivity for univalent cations, but the slow current was more selective for K+over Cl−(P  K:P  Cl = 3.6–4.2) than the fast current (P  K:P  Cl = 1.8–2.5) and also displayed Ca2+ selectivity. The slow current was blocked by Ba2+, whereas both currents were blocked by Gd3+ and La3+. Efflux of K+ from seed coat halves was inhibited 25% by Gd3+ and La3+ but was stimulated by Ba2+ and Cs+, suggesting that only the fast current may be a component in the pathway for K+ release. An “instantaneous” inward current observed in all protoplasts exhibited similar pharmacology and permeability for univalent cations to the fast outward current. In outside-out patches, two classes of depolarization-activated cation-selective channels were observed: one slowly activating of low conductance (determined from nonstationary noise to be 2.4 pS) and another with conductances 10-fold higher. Both channels occurred at high density. The higher conductance channel in 10 mm KCl hadP  K:P  Cl = 2.8. Such nonselective channels in the seed coat ground parenchyma cell could function to allow some of the efflux of phloem-imported univalent ions into the seed apoplast.
Brassinosteroid Mutants Uncover Fine Tuning of Phytochrome Signaling
Authors: Luccioni Laura G. , Oliverio Karina A. , Yanovsky Marcelo J. , Boccalandro Hernán E. , Casal Jorge J.
Published: November 2008

Phytochromes (phy) A and B provide higher plants the ability to perceive divergent light signals. phyB mediates red/far-red light reversible, low fluence responses (LFR). phyA mediates both very-low-fluence responses (VLFR), which saturate with single or infrequent light pulses of very low fluence, and high irradiance responses (HIR), which require sustained activation with far-red light. We investigated whether VLFR, LFR, and HIR are genetically coregulated. The Arabidopsis enhanced very-low-fluence response1mutant, obtained in a novel screening under hourly far-red light pulses, showed enhanced VLFR of hypocotyl growth inhibition, cotyledon unfolding, blocking of greening, and anthocyanin synthesis. However,eve1 showed reduced LFR and HIR. eve1 was found allelic to the brassinosteroid biosynthesis mutantdim/dwarf1. The analysis of both the brassinosteroid mutant det2 in the Columbia background (where VLFR are repressed) and the phyA eve1 double mutant indicates that the negative effect of brassinosteroid mutations on LFR requires phyA signaling in the VLFR mode but not the expression of the VLFR. Under sunlight, hypocotyl growth of eve1 showed little difference with the wild type but failed to respond to canopy shadelight. We propose that the opposite regulation of VLFR versus LFR and HIR could be part of a context-dependent mechanism of adjustment of sensitivity to light signals.
suppressor of sessile spikelets1Functions in theramosaPathway Controlling Meristem Determinacy in Maize
Authors: Wu Xianting , Skirpan Andrea , McSteen Paula
Published: November 2008

The spikelet, which is a short branch bearing the florets, is the fundamental unit of grass inflorescence architecture. In most grasses, spikelets are borne singly on the inflorescence. However, paired spikelets are characteristic of the Andropogoneae, a tribe of 1,000 species including maize (Zea mays). The Suppressor of sessile spikelets1 (Sos1) mutant of maize produces single instead of paired spikelets in the inflorescence. Therefore, the sos1 gene may have been involved in the evolution of paired spikelets. In this article, we show that Sos1 is a semidominant, antimorph mutation. Sos1 mutants have fewer branches and spikelets for two reasons: (1) fewer spikelet pair meristems are produced due to defects in inflorescence meristem size and (2) the spikelet pair meristems that are produced make one instead of two spikelet meristems. The interaction of Sos1 with the ramosa mutants, which produce more branches and spikelets, was investigated. The results show that Sos1 has an epistatic interaction with ramosa1 (ra1), a synergistic interaction with ra2, and an additive interaction with ra3. Moreover, ra1 mRNA levels are reduced in Sos1 mutants, while ra2 and ra3 mRNA levels are unaffected. Based on these genetic and expression studies, we propose that sos1 functions in the ra1 branch of the ramosa pathway controlling meristem determinacy.
Strategic sourcing for supply chain agility and firms' performance
Authors: Khan K Arif , Pillania Rajesh K.
Published: November 2008

Purpose

The purpose of this paper is to explore the dimensions of strategic sourcing and determines its relationship with organisational supply chain agility and performance. It classifies manufacturing firms based on their level of supply chain agility and test the diffrences in firms' performnace across the clusters so obtained.

Design/methodology/approach

This research employes survey method and data is collected from 128 manufacturing companies in India. Valid and reliable measures of strategic sourcing, supply chain agility and organizational performance are developed. Factor structure and initial validity is determined and K‐Means cluster analysis is applied for clustering firms based on their level of supply agility. Multiple regression and ANOVA is used for hypotheses testing.

Findings

Strategic suplier partnership, sourcing flexibility, supplier evaluation and trust in supply chain members are the key dimensions of strategic sourcing. Result shows the significant effect of strategic sourcing and its diemnsions on supply chain agility and firms' performance.

Research limitations/implications

Data is collected from single node/respondent of supply chain and further research can be carried out by using mutiple node data of each supply chain to make the research more meaningful and generalisable.

Practical implications

Findings are useful to develop and measure the competitive capabilities of strategic sourcing and guide the organisations to enhance supply chain responsiveness and organisational performance.

Originality/value

The paper provides strategic diemnsions of sourcing and their measurement scales. Provide evidence regarding the impact of strategic sourcing on agility of supply chains and performnace.
LOEX‐of‐the‐West 2008: hitting the jackpot in Las Vegas
Authors: Finley Priscilla , MacMillan Margy , Skarl Susie
Published: November 2008

Purpose

The purpose of this guest editorial is to provide an overview of the LOEX‐of‐the‐West 2008 Conference.

Design/methodology/approach

The paper is a review the conference, which was hosted by the University of Nevada, Las Vegas, and held from June 4‐6 on the UNLV campus.

Findings

The conference provided a forum for learning and thinking about gaming as it applies to information literacy instruction and for sharing ideas, techniques and concerns.

Originality/value

The paper gives an overview of the LOEX‐of‐the‐West 2008 Conference, and the issues raised there.
Form postponement effects on operational performance: a typological theory
Authors: Forza Cipriano , Salvador Fabrizio , Trentin Alessio
Published: November 2008

Purpose

The operational outcomes of form postponement (FP) have been increasingly investigated in the last two decades under the effects of escalating product variety and diffusion of mass customisation strategies. However, conflicting or hard‐to‐relate findings are quite frequent in the literature, so that a unifying framework for operations decision making is still lacking. The purpose of this paper is to develop a typological theory that reconciles into a coherent picture extant research on FP effects on operational performance.

Design/methodology/approach

The paper defines three mutually exclusive and exhaustive types of FP at the company level of analysis. Then, it revisits, through the lens of this typology, the literature on FP and formalizes how, why and under which assumptions each FP type affects operational performance.

Findings

The paper demonstrates that, to predict and explain FP effects on operational performance, three types of FP should be distinguished. In fact, it is shown that either these FP types have different effects on a given performance dimension, or they have the same effect but the logical justification for this effect is often different according to the FP type being considered.

Research limitations/implications

The paper's synopsis of past research accomplishments indicates that future work will have to investigate the operational implications of a specific FP type almost ignored in the literature, as well as test the relationships hypothesized in the literature. Further opportunities for future research include extending the level of analysis beyond the boundaries of the company and linking the paper's FP typology to the operations strategy discourse.

Practical implications

The lack of understanding of the benefits and costs of FP has been found to be a major obstacle to FP implementation. The paper's typological theory supports managerial decision making by clarifying what FP alternatives companies have and what are the operational implications for each of these alternatives.

Originality/value

The paper's typological theory reconciles apparently conflicting findings in the literature by explaining such differences in terms of differences in the FP type being investigated. Additionally, the typology helps avoid a twofold risk: on the one hand, the risk of generalizing an effect or mechanism that only applies to a specific FP type and, on the other hand, the risk of failing to detect type‐specific effects or mechanisms.
Report on an international conference on gender, class, employment and family
Authors: Lyonette Clare , Crompton Rosemary
Published: November 2008

Purpose

The purpose of this paper is to provide a brief summary of a series of papers presented at the gender, class, employment and family conference, held at City University, London, in March 2008.

Design/methodology/approach

The conference involved 25 papers presented by invited speakers, and the report is based on summary notes, observations and conference abstracts.

Findings

This report summarises a range of contributions, theoretical and empirical, to the continuing debates on gender and class inequality in Britain, Europe and the USA. The evidence presented not only demonstrated the persistence of gender and class inequalities, but also provided a critique of the “individualisation” thesis. The contribution of both normative and material factors to gender inequality was extensively explored. The discussions focused upon a series of tensions and contradictions – between “sameness” and “difference” feminism; choice and constraint; capitalist markets and the human requirement for caring work.

Originality/value

Many of the papers drew on original empirical research, both quantitative and qualitative, using sophisticated methodologies. Longitudinal findings (cohort studies) were well represented, as were cutting‐edge theoretical contributions.
Role of transparency in managing outcome successes
Authors: Jaffe Russell , Nash Robert A. , Ash Richard , Schwartz Norm , Corish Robert , Born Tammy , Carter James P. , Lazarus Harold
Published: November 2008

Purpose

Healthcare is both the largest (17 + percent) and the most rapidly growing (three plus times the consumer product index (measure of inflation) and half a percent of gross domestic product each year) segment of the US economy. The purpose of this paper is to focus on outcome successes that illustrate application of a previously reported health equation. The health equation allows an organized and more transparent assessment of healthcare outcomes.

Design/methodology/approach

The approach includes “end use/least cost” techniques that identifies healthful care as a big unmet need (BUN) and equally attractive business opportunity in identifying health promotion that improves outcome at lower net costs.

Findings

Opportunity exists to reduce costs while also reducing adverse events, healthcare morbidity and morality. Transparency is essential to find what works more effectively to yield desired outcomes. Metrics and measures, particularly more precise tools to assess true outcome in promoting health or managing ill health, are given priority as they allow quantified and, often econometric, outcome opportunities in the midst of current uncertainties.

Practical implications

This paper is for consumers and businesses, managers and administrators, professionals and allied health professionals. The successes described herein illustrate fundamental opportunities driving change and innovation within healthcare and in our society.

Originality/value

Attention is called to opportunity areas that can fund out of savings the transition from the authors' current “sickness care” system to a healthful care, proactive prevention approach to delivering care. Novel application of transparency and end use/least cost can help guide choices to achieve healthier outcomes.
Managing drought in mountain resort communities: Colorado's experiences
Authors: Wilhelmi Olga V. , Hayes Michael J. , Thomas Deborah S.K.
Published: November 2008

Purpose

This paper aims to investigate drought impacts and vulnerabilities specific to mountain resort communities and the implications for the tourism industry, in order to derive a set of recommendations for reducing drought vulnerability of this economic sector.

Design/methodology/approach

This article presents the results from a case study conducted in Colorado, USA, mountain communities evaluating the multi‐year drought that culminated in 2002. Using qualitative research methods, a series of interviews were conducted to garner the experiences of state and local tourism officials, ski resort representatives, and environmental, municipal and agricultural organizations.

Findings

This study finds that drought alone was not responsible for creating the variety of direct and secondary impacts on Colorado resort communities. The paper highlights the importance of water resources to the economic wellbeing of resort communities and recognizes the critical roles of communication, planning, media and public perception during a drought.

Originality/value

Societal vulnerability in mountain resort communities in relation to drought has rarely been addressed in the literature. The study provides specific recommendations to the resort managers and tourism officials for mitigating drought impacts of, and reducing resort communities' vulnerability to, drought.
Practices of Hong Kong building contractors in strategic asset allocation process: longitudinal approach
Authors: Lam K.C. , Wang D. , Lam M.C.K.
Published: November 2008

Purpose

The purpose of the paper is to report the investigation results of current practices of strategic asset allocation process, which consists of capital budget planning, monitoring, and control of Hong Kong building contractors. The changes of the said practices are compared with the results of the two similar surveys undertaken in the past longitudinally.

Design/methodology/approach

A total of 157 questionnaires were sent to about 1,000 approved Hong Kong building contractors (classified as group A, B, C in accordance with their maximum capacities). The total response rate was 30.7 per cent. Statistical techniques, a two‐dimensional contingency table, and discriminant function analysis (DA) were deployed to analyze the survey data via SPSS.

Findings

Only the practice of a regular review of the minimum rate of return of major projects was popular. For monitoring aspect, 100 per cent of surveyed contractors monitor project performance once operational. The result of post‐completion audits on major projects was 63 per cent. For the results of the longitudinal study, 66.7 per cent of group C firms employed the practices of intermediate and long‐term capital budgets and 71.4 per cent of large firms had a formal body for screening investment proposals compared with 54.8 per cent and 63.3 per cent of the same group's practices in 1994 respectively. DA results showed that the patterns within the three different groups (A, B, and C) were very similar, and group A and group B were active in capital budgeting monitoring and control.

Practical implications

Planning was the weakest and data showed that Hong Kong building contractors had tight control of the projects.

Originality/value

This paper reports the investigation results of current practices of strategic asset allocation process, which consists of capital budget planning, monitoring, and control of Hong Kong building contractors.
Pediatric liver transplantation: Review of the literature 2006–2007
Authors: Hind Jonathan M. , Kelly Deirdre A.
Published: November 2008

Abstract:  In recent years, significant developments have continued to be made in the field of pediatric liver transplantation. As experience increases, so there is now a wealth of outcome data. With improved patient and graft survival, issues such as quality of life and adherence to immunosuppressive medication regimes increase in importance, and affect outcomes. Demand for donor organs continues to increase, so surgical techniques and organ allocation policies are evolving to help meet this demand. Researchers have also looked at ways in which we might predict outcomes for liver transplant recipients, and how we may achieve increased graft tolerance in the future. By way of an introduction to recent articles in these exciting areas we have summarized several significant contributions from the hundreds of scientific articles related to pediatric liver transplantation published between 2006 and 2007. Comments linking themes across manuscripts have been included. This review is not exhaustive and we would encourage the reader to refer to the actual manuscripts and explore more deeply.
Damage model for environmental conditioned fatigue test with CAST
Authors: VIRGILI A. , PARTL M. N. , GRILLI A. , SANTAGATA F. A.
Published: November 2008

The aim of this paper is to suggest a unified test method that allows investigation into the different effects and contribution of water damage and temperature cycles on fatigue performance of asphalt mixtures by means of a CoAxial Shear Test (CAST). A continuum damage approach, based on the elasticity theory, is chosen to determine the damage level of each tested specimen. The proposed mathematical model allows the simulation of the modulus evolution in the fatigue test and takes into account the temperature cycles. In this way, a unique scalar damage factor determines the damage process severity in each specimen and allows a rational comparison between each different condition.
Coordinating community organizations in urban China
Authors: Chen Juan
Published: November 2008

Since its introduction in the 1980s, China's housing privatization reform has gradually transformed urban residents into private homeowners, and reinforced disparities in housing allocation and living conditions. Various studies have analyzed the mobilization of private homeowners in newly built, upscale apartment complexes. Using data from field observations and in‐depth interviews conducted in five low‐income, urban neighborhoods in Beijing in 1999–2000, this article investigates the shifts in the organizational and power structure in older, working‐class communities. The article describes the changing status of traditional and newly developed organizations and agencies within these neighborhoods, and analyzes the underlying reasons for the displacements and conflicts they experienced. Drawing on the author's subsequent fieldwork with community organizations in the USA in 2001–2002, the article suggests means of coordinating community organizations in low‐income, urban neighborhoods in China, and discusses the opportunities and challenges for the social work profession in its attempts to deliver social services and advocate social justice.
DISTRIBUTION, MORPHOLOGY, AND PHYLOGENY OF KLEBSORMIDIUM (KLEBSORMIDIALES, CHAROPHYCEAE) IN URBAN ENVIRONMENTS IN EUROPE1
Authors: Rindi Fabio , Guiry Michael D. , López‐Bautista Juan M.
Published: November 2008

Klebsormidium is a cosmopolitan genus of green algae, widespread in terrestrial and freshwater habitats. The classification of Klebsormidium is entirely based on morphological characters, and very little is understood about its phylogeny at the species level. We investigated the diversity and phylogenetic relationships of Klebsormidium in urban habitats in Europe by a combination of approaches including examination of field‐collected material, culture experiments conducted in many different combinations of factors, and phylogenetic analyses of the rbcL gene. Klebsormidium in European cities mainly occurs at the base of old walls, where it may produce green belts up to several meters in extent. Specimens from different cities showed a great morphological uniformity, consisting of long filaments 6–9 μm in width, with thin‐walled cylindrical cells and smooth wall, devoid of false branches, H‐shaped pieces, and biseriate parts. Conversely, the rbcL phylogeny showed a higher genetic diversity than expected from morphology. The strains were separated in four different clades supported by high bootstrap values and posterior probabilities. In culture, these clades differed in several characters, such as production of a superficial hydro‐repellent layer, tendency to break into short fragments, and inducibility of zoosporulation. On the basis of the taxonomic information available in the literature, most strains could not be identified unambiguously at the species level. The rbcL phylogeny showed no correspondence with classification based on morphology and suggested that the identity of many species, in particular the type species K. flaccidum (kütz.) P.C. Silva, Mattox et W. H. Blackw., needs critical reassessment.
Capsaicin‐ and Mustard Oil‐Induced Extracellular Signal‐Regulated Protein Kinase Phosphorylation in Sensory Neuronsin vivo: Effects of Neurokinins 1 and 2 Receptor Antagonists and of a Nitric Oxide Synthase Inhibitor
Authors: Donnerer Josef , Liebmann Ingrid , Schuligoi Rufina
Published: November 2008

Abstract: Stimulation of primary sensory neurons with capsaicin or mustard oil leads to phosphorylation of extracellular signal‐regulated protein kinase 1/2 (p‐ERK1/2) via activation of transient receptor potential V1 (TRPV1) or TRPA1, respectively. p‐ERK1/2 was determined by Western immunoblotting in the dorsal root ganglia and in the sciatic nerve of rats following either systemic or perineural capsaicin treatment, or mustard oil application to the hind paw skin. To investigate the possible involvement of neurokinin 1 (NK1) and NK2receptors as well as of nitric oxide, the selective antagonists, SR140333 for NK1and SR48968 for NK2, and the nitric oxide synthase inhibitor, NG‐nitro‐L‐arginine methyl ester (L‐NAME), were employed. The increase of p‐ERK1/2 after systemic capsaicin treatment was markedly attenuated by SR140333, while only the increase in the dorsal root ganglia was impaired by SR48968; in contrast, inhibition of nitric oxide synthase had no effect. Perineural capsaicin induced an increase in p‐ERK1/2 in the ipsilateral sciatic nerve and in the dorsal root ganglia. This effect was not influenced by SR140333 or L‐NAME. We found for the first time that mustard oil application to the hind paw skin caused an increase in p‐ERK1/2 in the sciatic nerve and in the dorsal root ganglia and only the phosphorylation in the latter was attenuated by SR140333 while L‐NAME showed no effect. From the present results, it may be assumed that capsaicin‐ or mustard oil‐induced p‐ERK1/2 in sensory neurons is not solely directly linked to TRPV1 or TRPA1 channels, but under certain conditions NK1‐ and NK2‐mediated mechanisms are involved.
Analytical prediction of the breakout noise from a rectangular cavity with one compliant wall
Authors: Venkatesham B. , Tiwari Mayank , Munjal M. L.
Published: November 2008

This paper describes an analytical calculation of breakout noise by incorporating three-dimensional effects along with the acoustical and structural wave coupling phenomena. The breakout noise phenomena from cavities are important at low frequencies, and the coupling between acoustic waves and structural waves plays a critical role in prediction of the transverse transmission loss. The first step in the breakout noise prediction is to calculate the inside cavity pressure field and the normal cavity wall vibration by using an impedance-mobility approach, which results in a compact matrix formulation. The second step is to calculate the radiated sound power from an unbaffled plate formulation that poses formidable challenges on computational time. The proposed formulation helps in reducing the computational time substantially by converting quadruple integrals into single integrals using an appropriate coordinate transformation technique. Analytical results are validated with the finite element/boundary element numerical models.
An active acoustic tripwire for simultaneous detection and localization of multiple underwater intruders
Authors: Folegot Thomas , Martinelli Giovanna , Guerrini Piero , Stevenson J. Mark
Published: November 2008

An algorithm allowing simultaneous detection and localization of multiple submerged targets crossing an acoustic tripwire based on forward scattering is described and then evaluated based upon data collected at sea. This paper quantifies the agreement between the theoretical performance and the results obtained from processing data gathered at sea for crossings at several depths and ranges. Targets crossing the acoustic field produce shadows on each side of the barrier, for specific sensors and for specific acoustic paths. In post-processing, a model is invoked to associate expected paths with the observed shadows. This process allows triangulation of the target’s position inside the acoustic field. Precise localization is achieved by taking advantage of the multipath propagation structure of the received signal, together with the diversity of the source and receiver locations. Environmental robustness is demonstrated using simulations and can be explained by the use of an array of sources spatially distributed through the water column.
Can the binaural system extract fine-structure interaural time differences from noncorresponding frequency channels?
Authors: Magezi David A. , Krumbholz Katrin
Published: November 2008

Due to the phase differences in the basilar membrane response between neighboring places along the cochlea, it is generally assumed that the processing of interaural time differences (ITDs) in the temporal fine structure relies on comparisons between corresponding frequency channels from the two ears. This study was aimed to test whether the auditory system is capable of extracting fine-structure ITDs from noncorresponding channels. For that, the ITD discrimination threshold was measured for a 500 Hz pure tone partially masked by a lowpass masker in one ear and a highpass masker in the other. The maskers were intended to obscure the apical or basal part of the tone’s excitation pattern, respectively, and thus force the listener to extract ITDs from disparate channels. While the results did not allow any definite conclusions as to whether or not ITD processing in these conditions was based on cross-channel comparisons, some aspects of the data suggest that it was. Modeling simulations showed that any cross-channel comparisons would have to be limited to a fairly narrow frequency range of little more than one auditory-filter bandwidth. However, the between-channel phase differences within even such a narrow range would be sufficient to explain ITD sensitivity in neurophysiological data.
Frequency dependence of backscatter from thin, oblique, finite-length cylinders measured with a focused transducer-with applications in cancellous bone
Authors: Wear Keith A. , Harris Gerald R.
Published: November 2008

A model is presented for the echo from a thin, oblique, finite-length cylinder. The echo is calculated from the line integral of the transducer directivity pattern along the cylinder axis. The model was validated with broadband pulse-echo measurements from (1) a perpendicular (to the ultrasound beam) nylon wire as a function of lateral displacement from the beam center, (2) a tilted nylon wire as a function of the angle of inclination relative to the ultrasound beam, and (3) a quasi-parallel-nylon-wire phantom, which mimicked the scattering properties of cancellous bone. The transducer directivity pattern (as a function of position and frequency) was measured with a membrane hydrophone. The model predicts an approximately cubic frequency dependence of backscatter coefficient from the phantom, as has been observed experimentally in cancellous bone. The model also predicts the relationship between the cylinder length and the exponent of a power law fit to backscatter coefficient versus frequency, which is 4 for very short (compared to a wavelength) cylinders and asymptotically approaches 3 for very long cylinders.
Linearly filtered estimation of the time-domain Green’s function from measurements of ambient noise
Authors: Albahrani S. A. , Frater M. R. , Huntington E. H.
Published: November 2008

It is possible to estimate the time-domain Green’s function of a channel based on measurements of ambient noise by sensors at either end of the channel. This paper presents theoretical results for the impact of filtering on this problem. These results lead to the development of two experimental rules-of-thumb. It is shown that there exists a relationship between system bandwidth and sensor separation, which determines the resolvability of the measurements. The relationship between high-pass filtering and differentiation is discussed, contributing to the debate about whether or not differentiation is required to estimate the time-domain Green’s function.
Individualized head-related transfer functions based on population grouping
Authors: Xu Song , Li Zhizhong , Salvendy Gavriel
Published: November 2008

A method is proposed to divide a population into different groups for partial individualization of head-related transfer functions (HRTFs). Borrowing the basic idea in sizing system design, factor analysis is used to identify the most representative measurements which are then in a case study used to group the population. The comparison between the group mean HRTFs and the population mean HRTFs shows that the group mean HRTFs could greatly reduce spectral distortion at most sampled positions.
Psychometric functions for hybrid difference discrimination/increment detection tasks
Authors: Shepherd Daniel , Hautus Michael J. , Hutchinson Hamish
Published: November 2008

Psychometric functions collected from difference discrimination tasks typically have slopes near 1, whereas those from increment detection tasks have slopes near 2. Experiments exploring the effect of stimulus configuration on the psychometric function were undertaken. Some stimuli were configured to conform to difference discrimination and increment detection tasks, while other “hybrid” stimulus configurations had physical properties associated with both tasks. The results suggest that these hybrid configurations may have psychophysical properties that fall in between those found for difference discrimination and increment detection tasks.