bluuebunny/crossref_metadata_2025 huggingface dataset:
Negative Regulation of Phosphate Starvation-Induced Genes
Authors: Mukatira Uthappa T. , Liu Chunming , Varadarajan Deepa K. , Raghothama Kashchandra G.
Published: November 2008

Phosphate (Pi) deficiency is a major nutritional problem faced by plants in many agro-ecosystems. This deficiency results in altered gene expression leading to physiological and morphological changes in plants. Altered gene expression is presumed to be due to interaction of regulatory sequences (cis-elements) present in the promoters with DNA binding factors (trans-factors). In this study, we analyzed the expression and DNA-protein interaction of promoter regions of Pi starvation-induced genes AtPT2 and TPSI1. AtPT2 encodes the high-affinity Pi transporter in Arabidopsis, whereas TPSI1 codes for a novel gene induced in the Pi-starved tomato (Lycopersicon esculentum). Expression of AtPT2 was induced rapidly under Pi deficiency and increased with decreasing concentrations of Pi. Abiotic stresses except Pi starvation had no affect on the expression of TPSI1. DNA mobility-shift assays indicated that specific sequences ofAtPT2 and TPSI1 promoter interact with nuclear protein factors. Two regions of AtPT2 andTPSI1 promoters specifically bound nuclear protein factors from Pi-sufficient plants. Interestingly, the DNA binding activity disappeared during Pi starvation, leading to the hypothesis that Pi starvation-induced genes may be under negative regulation.
A pilot study to evaluate gene expression profiles in peripheral blood mononuclear cells (PBMCs) from children with GH deficiency and Turner syndrome in response to GH treatment
Authors: Whatmore Andrew J. , Patel Leena , Clayton Peter E.
Published: November 2008

Response to GH treatment is variable and dependent on diagnosis and dose. We used a pharmacogenomic approach to assess whether this variability is reflected in patterns of GH‐induced gene expression in peripheral blood mononuclear cells (PBMCs) taken from three children with GH deficiency (GHD) and three girls with Turner syndrome (TS).

Analysis of the response to GH treatment revealed that in GHD, 15 probe sets (11 genes) showed a fold change > ± 1·4 at a P‐value < 0·0005 (and a false detection rate ≤ 15%). These genes included a suppressor of cytokine signalling (SOCS1) and a modulator of cAMP response elements (CREM). In marked contrast, in TS no genes fulfilled these criteria.

ANOVA identified a subset of genes significantly affected by diagnosis, GH treatment or an interaction between diagnosis and treatment (P < 0·05, n = 2266). Cluster analysis indicated that genes up‐regulated in both GHD and TS were related to DNA metabolism and transcription. Genes up‐regulated in GHD but down‐regulated in TS were involved in RNA processing and metabolism, whereas those down‐regulated in GHD and up‐regulated in TS were related to immune function.

This pilot study has shown that major changes in gene expression in PBMCs can only be seen with confidence in GHD inferring that the pattern of gene expression in response to GH in GHD vs. TS is distinct and disease‐specific. Further studies in larger cohorts will be required to evaluate whether GH‐induced PBMCs gene expression patterns can predict responses to GH in a clinical setting.
Ecosystem–atmosphere exchange of CH4 and N2O and ecosystem respiration in wetlands in the Sanjiang Plain, Northeastern China
Authors: SONG CHANGCHUN , XU XIAOFENG , TIAN HANQIN , WANG YIYONG
Published: November 2008

Natural wetlands are critically important to global change because of their role in modulating atmospheric concentrations of CO2, CH4, and N2O. One 4‐year continuous observation was conducted to examine the exchanges of CH4 and N2O between three wetland ecosystems and the atmosphere as well as the ecosystem respiration in the Sanjiang Plain in Northeastern China. From 2002 to 2005, the mean annual budgets of CH4 and N2O, and ecosystem respiration were 39.40 ± 6.99 g C m−2 yr−1, 0.124 ± 0.05 g N m−2 yr−1, and 513.55 ± 8.58 g C m−2 yr−1 for permanently inundated wetland; 4.36 ± 1.79 g C m−2 yr−1, 0.11 ± 0.12 g N m−2 yr−1, and 880.50 ± 71.72 g C m−2 yr−1 for seasonally inundated wetland; and 0.21 ± 0.1 g C m−2 yr−1, 0.28 ± 0.11 g N m−2 yr−1, and 1212.83 ± 191.98 g C m−2 yr−1 for shrub swamp. The substantial interannual variation of gas fluxes was due to the significant climatic variability which underscores the importance of long‐term continuous observations. The apparent seasonal pattern of gas emissions associated with a significant relationship of gas fluxes to air temperature implied the potential effect of global warming on greenhouse gas emissions from natural wetlands. The budgets of CH4 and N2O fluxes and ecosystem respiration were highly variable among three wetland types, which suggest the uncertainties in previous studies in which all kinds of natural wetlands were treated as one or two functional types. New classification of global natural wetlands in more detailed level is highly expected.
Children’s preferences of transfer devices for reconstitution of factors VIII and IX for the treatment of haemophilia
Authors: KHAIR K.
Published: November 2008

Summary.  The past decade has seen the introduction of a number of needleless transfer devices for the reconstitution of coagulation factors. This study investigated the use of four commercially available transfer devices by children with bleeding disorders, and assessed their preferences for the devices. Fifteen children with bleeding disorders requiring prophylactic home treatment with coagulation factors were recruited to the study. The participants tested reconstitution with four dummy transfer devices: BAXJECT, BIOSET, ReFacto R2 and Mix2Vial. Participants did not infuse the factors reconstituted using the devices. Each participant then answered a series of questions on each device; answers were based on a five‐point Likert scale and the devices were ranked in order of preference. All participants were able to use the devices within 5 min and 78% of participants ranked all devices as ‘fairly easy’ or ‘very easy’ to use. The most popular device was Mix2Vial, which was the most preferred by seven participants (46.7%). BAXJECT was the preferred device of four participants, but was also the least, or least but one, favourite of nine participants. Pre‐filled syringe transfer devices, BIOSET and ReFacto R2, were preferred by only 26% of participants. This is the first published study comparing children’s preferences for transfer devices. All children were able to manage the devices readily, and Mix2Vial was the preferred device of the majority of participants. Newer, advanced transfer devices offer a user‐friendly and more convenient and effective way for children to reconstitute factors.
Distribution Pattern of Neuropeptide Y in the Brain, Pituitary and Olfactory System during the Larval Development of the Toad Rhinella arenarum (Amphibia: Anura)
Authors: Heer T. , Pozzi A. G. , Yovanovich C. A , Paz D. A.
Published: November 2008

The first NPY‐immunoreactivity (ir) in the central nervous system of Rhinella arenarum was obtained just after hatching in the pre‐optic area, ventral thalamus and rostral rhombencephalon. During pre‐metamorphosis, new NPY‐ir cells were observed in other brain areas such as pallium, septum and striatum, infundibulum and pars intermedia of the pituitary. Further maturation continued through pro‐metamorphosis with the appearance of cell groups in the diagonal band, amygdala, pre‐optic nucleus, dorsal nucleus of the habenula, anterior ventral and dorsal thalamus, suprachiasmatic nucleus, tuberculum posterior, tectum, torus semicircularis, inter‐peduncular nucleus and median eminence. During the metamorphic climax and soon after, the relative abundance of NPY‐ir fibres decreased in all hypothalamic areas and the staining intensity and number of NPY‐ir cells in the pallium also decreased, whereas no cells were found in the striatum, dorsal nucleus of the habenula and tectum. In the olfactory epithelium, nerve or bulb, neither cells nor NPY‐ir fibres were found during the stages of development analysed. The ontogeny pattern of the NPY‐ir neuronal system in the brain of Rh. arenarum is more similar to the spatiotemporal appearance reported for Rana esculenta than to that reported for Xenopus laevis. Many NPY‐ir fibres were found in the median eminence and in the pars intermedia of the pituitary, supporting the idea that this neuropeptide may play a role in the modulation of hypophyseal secretion during development.
Expression of Leptin and Long‐form Leptin‐receptor Proteins in Porcine Hypothalamus during Oestrous Cycle and Pregnancy
Authors: Siawrys G , Kaminski T , Smolinska N , Przala J
Published: November 2008

Contents

In this study, we examined the levels of leptin and OB‐Rb protein expression in the discrete areas of the porcine hypothalamus (mediobasal hypothalamus – MBH, pre‐optic area – POA, stalk median eminence – SME) during mid‐ and late‐luteal phases of the oestrous cycle (days 10–12 and 14–16) as well as two stages of pregnancy (days 14–16 and 30–32). The analysis showed that during the cycle, leptin protein expression in MBH was higher in the mid‐luteal phase than late‐luteal phase. In the case of OB‐Rb protein expression, a higher level was observed in MBH during the late‐luteal phase in comparison to the mid‐luteal phase, whereas in POA and SME the opposite dependence was noticed. In turn, during pregnancy, leptin protein expression in MBH and POA, and OB‐Rb protein expression in POA were more pronounced on days 14–16 than on days 30–32. In contrast, leptin protein content in SME as well as OB‐Rb protein in MBH and SME was higher on days 30–32 than during the earlier stage of pregnancy. Comparison of leptin and OB‐Rb protein expression between the cycle (days 10–12) and pregnancy showed a higher level of leptin and OB‐Rb protein contents in POA as well as in SME during pregnancy (on days 14–16 and 30–32, respectively). Yet, OB‐Rb protein expression in POA on days 30–32 of pregnancy was lower in comparison to days 10–12 of the cycle. Furthermore, during pregnancy, leptin protein expression in MBH was lower (days 14–16 and 30–32), whereas OB‐Rb protein expression in that area of hypothalamus was higher (days 30–32) in comparison to the mid‐luteal phase. Our results indicate that both leptin and OB‐Rb are synthesized in the porcine hypothalamus and suggest the participation of leptin in auto/paracrine regulation of these brain areas functions, including control of reproduction during the oestrous cycle and early pregnancy.
Occupational Knowledge and Practice amongst UK University Research Administrators
Authors: Hockey John , Allen‐Collinson Jacquelyn
Published: November 2008

With the exception of lecturing staff, research on occupational groups and cultures within the UK higher education system is relatively sparse. This paper focuses upon one specialist group, to‐date under‐researched but which plays a central role in contemporary higher education administration: graduate research administrators. This occupational group is of particular interest as its members administer and manage an increasing complex and key area of university life, which in many cases appears to span the putative occupational divide between ‘academic’ and ‘administrative’ work. Based upon qualitative interviews with 27 research administrators, and using some of Bourdieu's conceptual devices, the paper analyses particular kinds of informal occupational knowledge and practice, necessary in order effectively to ‘do’ the complex task of research administration in the pressurized environment of contemporary British higher education.
Towards a Holistic Framework for Driving Performance in Externally‐Funded Academic Research
Authors: Hagermann Axel
Published: November 2008

A gradual shift in United Kingdom research funding from blanket financing by government agencies towards more diversified income streams through activities funded by various customers is prompting academic research institutions to orient their research portfolios accordingly. Academic organisations such as university institutes are increasingly relying on the funding obtained through research projects paid for by other customers than national funding bodies, thus diversifying their operations. Wrong choices in this diversification process can, however, have serious financial or operational implications for the organisation. A framework is proposed that should help enable academic institutes to rationalise their decision‐making processes when seeking external funding for their operations through project grants or research contracts and learn from projects.
The mechanisms of oxidative DNA damage and apoptosis induced by norsalsolinol, an endogenous tetrahydroisoquinoline derivative associated with Parkinson’s disease
Authors: Kobayashi Hatasu , Fukuhara Kiyoshi , Tada‐Oikawa Saeko , Yada Yuki , Hiraku Yusuke , Murata Mariko , Oikawa Shinji
Published: November 2008

Tetrahydroisoquinoline (TIQ) derivatives are putative neurotoxins that may contribute to the degeneration of dopaminergic neurons in Parkinson’s disease. One TIQ, norsalsolinol (NorSAL), is present in dopamine‐rich areas of human brain, including the substantia nigra. Here, we demonstrate that NorSAL reduces cell viability and induces apoptosis via cytochrome c release and caspase 3 activation in SH‐SY5Y human neuroblastoma cells. Cytochrome c release, caspase 3 activation, and apoptosis induction were all inhibited by the antioxidant N‐acetylcysteine. Thus, reactive oxygen species (ROS) contribute to apoptosis induced by NorSAL. Treatment with NorSAL also increased levels of oxidative damage to DNA, a stimulus for apoptosis, in SH‐SY5Y. To clarify the mechanism of intracellular DNA damage, we examined the DNA damage caused by NorSAL using 32P‐5′‐end‐labeled isolated DNA fragments. NorSAL induced DNA damage in the presence of Cu(II). Catalase and bathocuproine, a Cu(I) chelator, inhibited this DNA damage, suggesting that ROS such as the Cu(I)‐hydroperoxo complex derived from the reaction of H2O2 with Cu(I), promote DNA damage by NorSAL. In summary, NorSAL‐generated ROS induced oxidative DNA damage, which led to caspase‐dependent apoptosis in neuronal cells.
Intravenous Lidocaine in the Treatment of Refractory Headache: A Retrospective Case Series
Authors: Marmura Michael , Rosen Noah , Abbas Muhammad , Silberstein Stephen
Published: November 2008

Background.— New treatments are needed to treat chronic daily headache (CDH) and chronic cluster headache (CCH). New treatments are needed to treat this population and intravenous (IV) lidocaine is a novel treatment for CDH.

Objective.— The aim of this study was to examine the use of IV lidocaine for refractory CDH patients in an inpatient setting.

Methods.— This was an open‐label, retrospective, uncontrolled study of IV lidocaine for 68 intractable headache patients in an inpatient setting. We reviewed the medical records of patients receiving IV lidocaine between February 6, 2003 and June 29, 2005.

Results.— Pretreatment headache scores averaged 7.9 on an 11‐point scale and posttreatment scores averaged 3.9 representing an average change of 4. Average length of treatment was 8.5 days. Lidocaine infusion was generally well tolerated with a low incidence of adverse events leading to discontinuation of treatment.

Conclusions.— This study suggests benefit of lidocaine treatment and the need for further prospective analyses. The mechanism of lidocaine in treating headache is unknown.
ALKALINE PHOSPHATASE ACTIVITY AS A FUNCTION OF INTERNAL PHOSPHORUS CONCENTRATION IN FRESHWATER PHYTOPLANKTON1
Authors: Litchman Elena , Nguyen Binh L. V.
Published: November 2008

Single‐cell alkaline phosphatase (AP) activity is being increasingly used to characterize phosphorus (P) status of individual species of phytoplankton. As phytoplankton growth rates depend more directly on the internal rather than external P concentrations, we determine the AP activity in the two species of freshwater phytoplankton, Scenedesmus quadricauda (Turpin) Bréb. and Asterionella formosa Hassall, as a function of internal P concentration. AP activity strongly correlated with cellular P, increasing almost linearly with decreasing cellular P in both species. The dynamics of initial responses of AP activity to P limitation, as well as the final levels of AP activity, when cellular P approached minimum quotas, differed in two species. After P addition, cellular P concentrations increased rapidly, but AP activity remained high for several days. The lag in AP activity down‐regulation following an increase in cellular P made it difficult to infer current P status of cells under dynamic P conditions.
Cognitive Decline and Mortality in a Community‐Based Cohort: The Monongahela Valley Independent Elders Survey
Authors: Lavery Laurie L. , Dodge Hiroko H. , Snitz Beth , Ganguli Mary
Published: November 2008

OBJECTIVES: To compare, in a longitudinal cohort study, declines in specific cognitive domains on their ability to predict time to death, in the presence and absence of dementia, and to explore an explanatory role for vascular disease.

DESIGN: Prospective population‐based epidemiological study.

SETTING: The mid‐Monongahela valley of southwestern Pennsylvania from 1987 to 2002.

PARTICIPANTS: Nine hundred eighty‐nine community‐dwelling adults aged 65 and older enrolled in the Monongahela Valley Independent Elders Survey.

MEASUREMENTS: Biennial assessments of a range of cognitive domains for up to 12 years. Mortality was modeled as a function of decline in each domain, adjusting for vascular diseases and stratified according to age (≤75 (younger‐old) and >75 (older‐old)) using Cox proportional hazards modeling.

RESULTS: Average annual declines in almost all cognitive domains were significant predictors of mortality in the cohort as a whole. However, after adjustment for dementia, only general cognition, processing speed, the language composite, and the executive function composite remained significant. Adjustment for vascular diseases did not alter the results. In the younger‐old group, decline in memory (hazard ratio (HR)=21.4) and executive function (HR=25.5) remained strong predictors after adjustment for dementia and vascular disease. In the older‐old group, decline in processing speed was a strong predictor of mortality before (HR=7.4) and after (HR=5.3) controlling for dementia and vascular diseases.

CONCLUSION: Decline in most cognitive domains predicted mortality across the cohort, but declines in memory and learning were not independent of dementia. Different domains predicted mortality in the younger and older subgroups.
Problems and Challenges in Reforming International Agricultural Economics
Authors: Hedley Douglas D.
Published: November 2008

Starting from the premise that the agricultural economics profession is defined primarily by the range of problems on which it works, as opposed to the initial or developmental training of the individuals, the traditional analyses base narrowly on the neoclassical paradigm are increasingly insufficient for the problems commonly found in the agri‐food industry. Two areas in which the profession is particularly weak are the economics and evolution of institutions, and the human capital component in economic development. For the latter, it includes both matching training to the nature and scope of problems facing individuals and the economics of human capital development and maintenance for a viable and growing agri‐food industry. As well, new areas of endeavour such as environmental sustainability and property rights associated with biotechnology offer opportunity for leadership from the profession. Finally, with increasingly complex and interdependent problems in the agri‐food sector, as well as the need to integrate processes for change into the analytical tool kit of the profession, the concept of strategic linkages across disciplines and professions will need to be pursued. Without such a multidisciplinary interdisciplinary approach, professional analysis founded narrowly on the neoclassical paradigm defeats the problem solving strength the profession has nurtured
Land Set Aside: Is It Food Security?1
Authors: Gray Richard , Paddock Brian
Published: November 2008

Land set aside programs can provide substantial economic benefits in distorted agricultural markets. Their incidence of use is increasing in the US, Canada and particularly in the EC. Voluntary annual programs have a small negative impact on short run food security while more permanent programs have slightly larger effects. The long run impact on food security is determined by whether the program leads to soil conservation or not. Most set aside programs used in Canada, the US and EC have some negative implications for food security. A well designed set aside can enhance long term food security with a limited effect short run food security
Rapid real‐time PCR assay for detection of MPL W515L mutation in patients with chronic myeloproliferative disorders
Authors: GHADERI M. , STRÖMBERG O. , PORWIT A.
Published: November 2008

Clinical diagnosis of the myeloproliferative disorders (MPD) has previously been based on clinical data and bone marrow morphology due to lack of specific molecular markers. The discovery of JAK2 V617F mutation has shed light on understanding of the molecular pathways involved in the pathogenesis of the myeloproliferative disorders. The thrombopoietin receptor gene (MPL) is expressed in megakaryocytes and exhibits the gain of function point mutation in ∼5% of MPDs. Several research groups have used real‐time PCR to detect and quantify the presence of JAK2 V617F mutation. We report here a highly specific real‐time assay based on the TaqMan® technology to detect the MPL W515L mutation with high sensitivity from the patient's blood. This assay can be easily performed together with the JAK2 V617F mutation assay on the same real‐time PCR reaction plate.
Temporal coherence after multiple forward scattering through random three-dimensional inhomogeneities in an ocean waveguide
Authors: Chen Tianrun , Ratilal Purnima , Makris Nicholas C.
Published: November 2008

An analytical expression is derived for the temporal coherence of an acoustic field after multiple forward scattering through random three-dimensional (3D) inhomogeneities in an ocean waveguide. This expression makes it possible to predict the coherence time scale of field fluctuations in ocean-acoustic measurements from knowledge of the oceanography. It is used to explain the time scale of acoustic field fluctuations observed at megameter ranges in various deep ocean-acoustic transmission experiments. It is shown that this time scale is nonlinearly related to the much longer coherence time scale of deep ocean internal waves through a multiple forward scattering process. It is also shown that 3D scattering effects become pronounced when the acoustic Fresnel width exceeds the cross-range coherence length of the deep ocean internal waves, which lead to frequency and range-dependent power losses in the forward field that may help to explain historic long range measurements.
Influence of material viscoelasticity on the scattering of guided waves by defects
Authors: Predoi Mihai V. , Castaings Michel , Moreau Ludovic
Published: November 2008

Guided waves are potential candidates for the nondestructive evaluation of viscoelastic structures due to their relatively long range of propagation. The major drawback is the difficulty in interpreting the scattered waves especially at high frequency-thickness values since many modes then exist. Moreover, in damping material waveguides, each mode of the scattered field has its own attenuation. Viscoelastic material characterization has been widely investigated by many authors in the past, but very few are treating multimodal scattering by discontinuities in viscoelastic guide. The scattering of a pure fundamental mode incident on a trough in a viscoelastic plate is investigated in this paper, over a relatively large frequency range, with up to five scattered modes. A hybrid two-dimensional finite element and modal projection method is used, based on modal orthogonality, to obtain the relative energy fluxes of each mode. Experiments are also made to validate the numerical predictions.
Waveguide invariant broadband target detection and reverberation estimation
Authors: Goldhahn Ryan , Hickman Granger , Krolik Jeffrey
Published: November 2008

Reverberation often limits the performance of active sonar systems. In particular, backscatter off of a rough ocean floor can obscure target returns and/or large bottom scatterers can be easily confused with water column targets of interest. Conventional active sonar detection involves constant false alarm rate (CFAR) normalization of the reverberation return which does not account for the frequency-selective fading caused by multipath propagation. This paper presents an alternative to conventional reverberation estimation motivated by striations observed in time-frequency analysis of active sonar data. A mathematical model for these reverberation striations is derived using waveguide invariant theory. This model is then used to motivate waveguide invariant reverberation estimation which involves averaging the time-frequency spectrum along these striations. An evaluation of this reverberation estimate using real Mediterranean data is given and its use in a generalized likelihood ratio test based CFAR detector is demonstrated. CFAR detection using waveguide invariant reverberation estimates is shown to outperform conventional cell-averaged and frequency-invariant CFAR detection methods in shallow water environments producing strong reverberation returns which exhibit the described striations.
Representation of the spectral dominance region of pitch in the steady-state temporal discharge patterns of cochlear nucleus units
Authors: Shofner William P.
Published: November 2008

Single-unit responses to infinitely iterated rippled noise and wideband noise were recorded from the cochlear nucleus of anesthetized chinchillas. Rippled noises had a fixed delay of 4ms, and spectral depth was varied by attenuating the delayed version of the noise. Temporal discharge patterns were analyzed using neural autocorrelograms, and responses to rippled noises were compared to wideband noise responses. Chopper units with best frequencies in the range of the first to second harmonics of the rippled noise showed large differences in discharge patterns between rippled noise and wideband noise responses, but chopper units with best frequencies centered at higher harmonics did not show large differences. Consequently, the Chopper group of units showed no evidence of a neural representation of the dominance region. Primarylike units did show a neural representation of dominance that is related to behavioral performance. For Primarylike units with best frequencies around the third to fifth harmonics of the rippled noise, large differences in discharge patterns between rippled noise and wideband noise responses were observed. The results suggest that bushy cells play an important role in processing pitch-related information and should be included as important elements in neural models of periodicity processing.
A linear model of acoustic-to-facial mapping: Model parameters, data set size, and generalization across speakers
Authors: Craig Matthew S. , van Lieshout Pascal , Wong Willy
Published: November 2008

The relationship between acoustic and visual speech is important for understanding speech perception, but it also forms the basis behind a type of facial animator, which can predict facial motion during speech given an acoustic input. This relationship was examined by revisiting a linear transformation model of audio-visual speech production. A mathematical model is constructed whereby the visual aspect of speech is reproduced from the acoustic signal via a linear transformation. Unlike previous studies in this area, this paper will address specific aspects of the model as related to the effects of window size for acoustic framing and the critical size of the training set. On average, facial motion is predicted with a correlation of 0.70 to the recorded motion, when the model is trained and then tested on the same subject. This is comparable to previous studies using either similar or different model approaches. Using a model trained on other subjects and then applying it to a new subject resulted in a prediction correlation of 0.65. Furthermore, acoustic windows of 100ms and a data set of approximately 40 sentences are required for maximum predictability. The results are interpreted in terms of the underlying assumptions of the model.
Scattering of the fundamental shear horizontal mode in a plate when incident at a through crack aligned in the propagation direction of the mode
Authors: Ratassepp M. , Lowe M. J. S. , Cawley P. , Klauson A.
Published: November 2008

A study of the scattering of the fundamental guided wave SH0 at a through-thickness narrow notch directed along the wave’s propagation in a plate is presented. The results are obtained from Finite Element simulations and experimental measurements. Good agreement is found between the simulations and the measurements. The results are shown for a range of crack lengths and shapes. The scattered wave field consists of the reflected and diffracted SH0 mode and also contributions from mode conversions to the S0 mode. It is found that the coefficient of direct reflection of the SH0 mode has an undulating nature depending on the length of the crack. This is caused by interference phenomena that are related to the interaction of different surface wave types generated on the crack surfaces and their diffractions at both tips of the crack. It is shown that the dominating part of this reflection is generated by the delayed “Rayleigh type” surface waves reflected from the far tip of the crack.
Interaction of reed and acoustic resonator in clarinetlike systems
Authors: Silva Fabrice , Kergomard Jean , Vergez Christophe , Gilbert Joël
Published: November 2008

Sound emergence in clarinetlike instruments is investigated in terms of instability of the static regime. Various models of reed-bore coupling are considered, from the pioneering work of Wilson and Beavers [“Operating modes of the clarinet,” J. Acoust. Soc. Am. 56, 653–658 (1974)] to more recent modeling including viscothermal bore losses and vena contracta at the reed inlet. The pressure threshold above which these models may oscillate as well as the frequency of oscillation at threshold are calculated. In addition to Wilson and Beavers’ previous conclusions concerning the role of the reed damping in the selection of the register the instrument will play on, the influence of the reed motion induced flow is also emphasized, particularly its effect on playing frequencies, contributing to reduce discrepancies between Wilson and Beavers’ experimental results and theory, despite discrepancies still remain concerning the pressure threshold. Finally, analytical approximations of the oscillating solution based on Fourier series expansion are obtained in the vicinity of the threshold of oscillation. This allows to emphasize the conditions which determine the nature of the bifurcation (direct or inverse) through which the note may emerge, with therefore important consequences on the musical playing performances.
Speech production modifications produced by competing talkers, babble, and stationary noise
Authors: Lu Youyi , Cooke Martin
Published: November 2008

Noise has an effect on speech production. Stationary noise and babble have been used in the past but the effect of a competing talker, which might be expected to cause different types of disruption, has rarely been investigated. The current study examined the acoustic and phonetic consequences of N-talker noise on sentence production for a range of values of N from 1 (competing talker) to infinity (speech-shaped noise). The effect of noise on speech production increased with both the number of background talkers (N) and noise level, both of which act to increase the energetic masking effect of the noise. In a background of stationary noise, noise-induced speech was always more intelligible than speech produced in quiet, and the gain in intelligibility increased with N and noise level, suggesting that talkers modify their productions to ameliorate energetic masking at the ears of the listener. When presented in a competing talker background, speech induced by a competing talker was more intelligible than speech produced in quiet, but the scale of the effect was compatible with the energetic masking effect of the competing talker. No evidence was found of modifications to speech production which exploited the temporal structure of a competing talker.
A re-evaluation of the relation between physiological channel interaction and electrode pitch ranking in cochlear implants
Authors: Hughes Michelle L.
Published: November 2008

Spatial excitation patterns in cochlear implant users can be measured with the electrically evoked compound action potential (ECAP). This study examined whether the relative separation of ECAP excitation patterns for two electrodes was correlated with the ability to discriminate those electrodes on the basis of pitch. Significant correlations were found for nine of the ten subjects. Electrodes with significant relative overlap of ECAP spatial excitation patterns were generally more difficult to distinguish on the basis of pitch. Pitch-ranking ability and overlap of ECAP patterns were both affected by the relative separation between electrodes in each pair. With increased separation between electrodes, pitch ranking improved significantly, and ECAP spatial excitation patterns showed significantly less overlap.
Preliminary mapping of void fractions and sound speeds in gassy marine sediments from subbottom profiles
Authors: Leighton T. G. , Robb G. B. N.
Published: November 2008

Bubbles of gas (usually methane) in marine sediments affect the load-bearing properties of the seabed and act as a natural reservoir of “greenhouse” gas. This paper describes a simple method which can be applied to historical and future subbottom profiles to infer bubble void fractions and map the vertical and horizontal distributions of gassy sediments, and the associated sound speed perturbations, even with single-frequency insonification. It operates by identifying horizontal features in the geology and interpreting any perceived change of depth in these as a bubble-mediated change in sound speed.
Next steps toward improving classroom acoustics for all.
Authors: Nelson Peggy
Published: November 2008

For the past ten years, the ASA has been very influential in the improvement of classroom acoustics, especially with the adoption of ANSI S12.60-2002. In fact, we have been a part of a worldwide effort to improve the learning environments for children, thanks in large part to the efforts of Nixon. Even after the adoption of the standard, we must still be involved in local and state policy decisions involving classroom acoustics, especially in urban districts with older school buildings, diverse students, and declining enrollment. We can and should form partnerships with personnel in local school districts to evaluate and fix acoustical problems in schools. Recently we worked with a local urban school district to evaluate schools and determine the best investment for improving acoustics. In some schools, sustained noise levels were well over 65 dBA, largely because of poor quality doors and windows that allowed in high levels of external noise from hallways and outside. Solutions included: damping ventilation vibration, adding door seals, and judicious use of amplification systems when higher-signal levels were needed. In most cases, reducing noise problems at the source was the best investment of district funds.
COMPUTATION BY ANNOTATION: MODELLING EPIGENETIC REGULATION
Authors: BIEGLER FRANZISKA , DALEY MARK , LOCKE M. ELIZABETH O.
Published: November 2008

We present a formal model inspired by the epigenetic process of gene annotation via histone modification. In particular, we study the generative capacity of a system in which annotations on a set of strings control which substrings are ultimately produced by the system and in which only the annotations, and not the strings themselves, may be rewritten. On a biological level this represents a first attempt to better understand the computational limits of this form of epigenetic regulation. We introduce two different derivation modes for our formal system and show that these systems are actually quite weak. The weaker of the derivation modes is directly capable only of generating a subset of the regular languages while the more powerful derivation mode is also only capable of generating all regular languages modulo a begin- and an end-marker.
ON THE DESCRIPTIONAL COMPLEXITY OF ACCEPTING NETWORKS OF EVOLUTIONARY PROCESSORS WITH FILTERED CONNECTIONS
Authors: DRĂGOI CEZARA , MANEA FLORIN
Published: November 2008

In this paper we consider, from the descriptional complexity point of view, a model of computation introduced in [1], namely accepting network of evolutionary processors with filtered connections (ANEPFCs). First we show that for each morphism h : V → W*, with V ∩ W = ∅, one can effectively construct an ANEPFC, of size 6 + |W|, which accepts every input word w and, at the end of the computation on this word, obtains h(w) in its output node. This result can be applied in constructing two different ANEPFCs, with 27 and, respectively, 26 processors, recognizing a given recursively enumerable language. The first architecture, based on the construction of a universal ANEPFC, has the property that only 7 of its 27 processors depend on the accepted language. On the other hand, all the 26 processors of the second architecture depend on the accepted language, but, differently from the first one, this network simulates efficiently (from both time and space perspectives) a nondeterministic Turing machine accepting the given language.
DISCRETE NONDETERMINISTIC MODELING OF THE FAS PATHWAY
Authors: JACK JOHN , RODRÍGUEZ-PATÓN ALFONSO , IBARRA OSCAR H. , PĂUN ANDREI
Published: November 2008

Computer modeling of molecular signaling cascades can provide useful insight into the underlying complexities of biological systems. We present a refined approach for the discrete modeling of protein interactions within the environment of a single cell. The technique we offer utilizes the Membrane Systems paradigm which, due to its hierarchical structure, lends itself readily to mimic the behavior of cells. Since our approach is nondeterministic and discrete, it provides an interesting contrast to the standard deterministic ordinary differential equations techniques. We argue that our approach may outperform ordinary differential equations when modeling systems with relatively low numbers of molecules – a frequent occurrence in cellular signaling cascades.

Refinements over our previous modeling efforts include the addition of nondeterminism for handling reaction competition over limited reactants, increased efficiency in the storing and sorting of reaction waiting times, and modifications of the model reactions. Results of our discrete simulation of the type I and type II Fas-mediated apoptotic signaling cascade are illustrated and compared with two approaches: one based on ordinary differential equations and another based on the well-known Gillespie algorithm.
ON A CHARACTERIZATION OF CELLULAR AUTOMATA IN TILINGS OF THE HYPERBOLIC PLANE
Authors: MARGENSTERN MAURICE
Published: November 2008

In this paper, we look at the extension of Hedlund's characterization of cellular automata to the case of cellular automata in the hyperbolic plane. This requires an additional condition. The new theorem is proved with full details in the case of the pentagrid and in the case of the ternary heptagrid and enough indications to show that it also holds on the grids {p, q} of the hyperbolic plane.
SOME COMPUTATIONS ON FUZZY MATRICES: AN APPLICATION IN FUZZY ANALYTICAL HIERARCHY PROCESS
Authors: DEHGHAN MEHDI , GHATEE MEHDI , HASHEMI BEHNAM
Published: November 2008

Fuzzy mathematics is a generalization in which fuzzy numbers replace real numbers and fuzzy arithmetic replaces real arithmetic. It is an excellent scope for modeling vague and uncertain aspects of the actual environments. In this important area, Dubois and Prade1 defined a fuzzy matrix as a rectangular array of fuzzy numbers. They have also defined the LR type fuzzy numbers with some useful approximate arithmetic operators. The aim of this paper is to extend some useful aspects of linear algebra e.g. determinant, norm and eigenvalue for fuzzy matrices with LR fuzzy number entries by the use of fuzzy arithmetic. Finally, applications in fuzzy analytical hierarchy process (AHP) are investigated.
BLUESHIFT AND INTENSITY ENHANCEMENT IN VISIBLE EMISSION SPECTRUM OF C-AXIS ORIENTED SPRAY PYROLYTICALLY GROWN NANOCRYSTALLINE ZnO THIN FILMS
Authors: BUSHIRI M. JUNAID , GOPAKUMAR V. , VAIDYAN V. K.
Published: November 2008

Highly (002)-oriented nanocrystalline ZnO thin films were deposited on glass substrates at a substrate temperature of 500°C in air atmosphere by low-cost spray pyrolysis method. Room temperature photoluminescence spectral studies show the presence of near band edge emission and defect level emission (DLE) from the samples. The DLE wavelength is blueshifted about 22 nm and further emission intensity enhancement is observed in (002)-oriented sample as compared to that of wurtzite ZnO phase. The modifications in local defect levels and change in crystalline symmetry are attributed to the blue shift in the DLE region of c-axis oriented sample. The increased emission intensity of (002)-oriented samples is due to improvement in crystalline quality, preferential oriented growth and spherical morphology of nanocrystalline grains.
SYNTHESIS AND CHARACTERIZATION OF α-Fe2O3@ATO NANOCOMPOSITE PARTICLES
Authors: ZHU YIN-CUN , JIANG JI-SEN
Published: November 2008

α- Fe 2 O 3@ATO (antimony doped tin oxide) nanocomposite particles with core–shell structure were prepared by homogeneous precipitation method using monodispersed α- Fe 2 O 3 (hematite) nanoparticles as cores, SnCl 4 · 5 H 2 O and SbCl 3 as the precursor of the shell. The morphology and structure of the nanocomposite particles were studied with transmission electron microscopy and X-ray diffraction, respectively. The electricity properties of the nanocomposite were also investigated in terms of coating amount, molar ratio of element Sb to Sn , and heat treatment conditions. The results showed that the conditions of ATO/α- Fe 2 O 3 (weight ratio) = 70%, n( Sb )/n( Sn ) = 10%, calcined at 700°C for 1 h were optimal for the conductivity of the nanocomposite.
FIELD-ION MICROSCOPY OBSERVATIONS AND ATOMISTIC SIMULATIONS OF RIGID-BODY SHIFTS AT TILT GRAIN BOUNDARIES IN TUNGSTEN
Authors: AZHAZHA V. M. , NEKLYUDOV I. M. , KSENOFONTOV V. A. , MAZILOVA T. I. , MIKHAILOVSKIJ I. M. , SADANOV E. V. , MAZILOV A. A.
Published: November 2008

Field-ion microscopy and molecular dynamics simulation were used for the characterization of the translation states at special grain boundaries in tungsten. It is revealed that rigid-body displacement had the component of displacement parallel to the [110] direction equal to 0 or 1 interplanar spacing. Full vectors of lateral shifts are described by broad statistical distribution. The mathematical simulation revealed two mirror-symmetry-breaking lateral translations along the [Formula: see text] direction of the Σ9 grain boundary corresponding to different atomic structures. It is shown that the partial disconnection with the [Formula: see text] Burgers vector can be considered as the elemental carriers of grain-boundary polymorphic transformation.
TEMPERATURE DEPENDENCE OF ELECTROLESS Ni–P DEPOSITION ON POLYESTER FABRIC
Authors: GUO R. H. , JIANG S. Q. , YUEN C. W. M. , NG M. C. F.
Published: November 2008

The effects of plating temperature on the plating rate, P content, surface morphology, and electrical resistance of the electroless Ni–P deposits were studied. The results showed that the deposition rate of the Ni–P deposit and P content of the Ni–P layer increased with the rise of temperature of the plating bath. Scanning electron microscopy of the Ni–P deposits showed a nodule structure. The Ni–P plating layers had an amorphous structure and surface resistance of the layer decreased with the rise of temperature. In addition, the electromagnetic interference shielding effectiveness (EMI SE) of electroless Ni–P plated polyester fabric was also investigated. The result indicated that EMI SE of Ni–P plated polyester fabric was close to 45–50 dB when the surface resistance was 0.63 Ω/□.
p-GaN/n-Si HETEROJUNCTION PHOTODIODES
Authors: CHUAH L. S. , HASSAN Z. , ABU HASSAN H. , HUSSEIN MOURAD M.
Published: November 2008

PN photodiodes, as an alternative form of photodetectors, is based on carrier production in the high-field junction region, and it has a response time considerably faster than that of a photoconductor and is typically in the order of nanoseconds. Photodetectors operating in the short wavelength ultraviolet (UV) region are important devices that can be used in various commercial and military applications. In the present work, we fabricated the p- GaN / n-Si heterojunction photodiode to observe the photoelectric effects. From the results, the current–voltage characteristics of the device show the typical rectifying behavior of heterojunctions. The UV photocurrent measurement was performed using an Hg -lamp under a reverse bias.
ELECTROCHEMICAL BEHAVIORS OF MATRINE AT L-CYSTEINE-MODIFIED ELECTRODES
Authors: MIAO YUQING , CHEN JIANRONG , WU XIAOHUA
Published: November 2008

Matrine is an important natural occurring component in sophora roots. It has a wide range of pharmacological actions. In this work, electrochemical investigation of matrine and its interaction with L-cysteine (L-Cys) is reported. Via the electrochemical approach, we have proved that the distribution coefficients of protonated and deprotonated matrine affect its electrochemical response on Au or L-Cys modified Au electrodes. The study by ultraviolet spectroscopy also finds that the molecular interaction between matrine and L-Cys changes with the distribution coefficients of protonated and deprotonated matrine at different pH value. Compared with the response of matrine on the bare gold electrode, the L-Cys/Au self-assembled monolayers modified electrodes exhibit obviously higher current response toward matrine oxidation. The oxidation current of matrine at L-Cys assembled electrode has a good linear relation in the range of 0.2–5 mM, with the correlation coefficient of 0.989 by cyclic voltammagrams. Electrochemical combined with spectroscopic techniques would provide relatively easy way to better understand the underlying mechanism of matrine/L-Cys interaction and will be helpful for the development of electroanalytical techniques for the determination of matrine.
The Study of Triple Integral Equations with Generalized Legendre Functions
Authors: Singh B. M. , Rokne J. , Dhaliwal R. S.
Published: November 2008

A method is developed for solutions of two sets of triple integral equations involving associated Legendre functions of imaginary arguments. The solution of each set of triple integral equations involving associated Legendre functions is reduced to a Fredholm integral equation of the second kind which can be solved numerically.
Molybdenum and Tungsten Tricarbonyl Complexes of Isatin with Triphenylphosphine
Authors: Khalil M. M. H. , Al-Seif F. A.
Published: November 2008

Reaction of M(CO)6; M = Mo or W with isatin in the presence of triphenylphosphine in THF under reduced pressure gave the tricarbonyl derivatives complexes [M(CO)3(isatH)(PPh3)]. The two complexes were characterized by elemental analysis, infrared, mass and  1H NMR spectroscopy. The spectroscopic studies show that the two complexes exist in fac‐ and mer‐isomers in solutions through exchange the CO group and PPh3. The Uv‐Vis spectra of the complexes in different solvents were studied.