bluuebunny/crossref_metadata_2025 huggingface dataset:
Object Familiarity and Semantic Congruency Modulate Responses in Cortical Audiovisual Integration Areas
Authors: Hein Grit , Doehrmann Oliver , Müller Notger G. , Kaiser Jochen , Muckli Lars , Naumer Marcus J.
Published: July 2007

The cortical integration of auditory and visual features is crucial for efficient object recognition. Previous studies have shown that audiovisual (AV) integration is affected by where and when auditory and visual features occur. However, because relatively little is known about the impact of what is integrated, we here investigated the impact of semantic congruency and object familiarity on the neural correlates of AV integration. We used functional magnetic resonance imaging to identify regions involved in the integration of both (congruent and incongruent) familiar animal sounds and images and of arbitrary combinations of unfamiliar artificial sounds and object images. Unfamiliar object images and sounds were integrated in the inferior frontal cortex (IFC), possibly reflecting learning of novel AV associations. Integration of familiar, but semantically incongruent combinations also correlated with IFC activation and additionally involved the posterior superior temporal sulcus (pSTS). For highly familiar semantically congruent AV pairings, we again found AV integration effects in pSTS and additionally in superior temporal gyrus. These findings demonstrate that the neural correlates of object-related AV integration reflect both semantic congruency and familiarity of the integrated sounds and images.
Linking Neuronal and Behavioral Performance in a Reaction-Time Visual Detection Task
Authors: Palmer Chris , Cheng Shao-Ying , Seidemann Eyal
Published: July 2007

Perceptual decisions are likely to be based on signals that are provided by populations of neurons in early sensory cortical areas. How these neural responses are combined across neurons and over time to mediate behavior is unknown. To study the link between neural responses and perceptual decisions, we recorded the activity of single units (SU) and multiple units (MU) in the primary visual cortex (V1) of monkeys while they performed a reaction-time visual detection task. We then determined how well the target could be detected from these neural signals. We found that, on average, the detection sensitivities supported by SU and MU in V1 are comparable with the detection sensitivity of the monkey even when considering neural responses during brief temporal intervals (median duration, 137 ms) that ended shortly before the monkey's reaction time. However, we observed systematic differences between the overall shape of the neurometric functions and the monkey's psychometric functions. We also examined the quantitative relationship between SU and MU activity and found that MU responses are consistent with the sum of the responses of multiple SU, most of which have low stimulus selectivity. Finally, we found weak but significant trial-to-trial covariations between V1 activity and behavioral choices, demonstrating for the first time that choice probability can be observed at the earliest stages of cortical sensory processing. Together, these results suggest that the activity of a large population of V1 neurons is combined suboptimally by subsequent processing stages to mediate behavioral performance in visual detection tasks.
Evidence That Long-Term Potentiation Occurs within Individual Hippocampal Synapses during Learning
Authors: Fedulov Vadim , Rex Christopher S. , Simmons Danielle A. , Palmer Linda , Gall Christine M. , Lynch Gary
Published: July 2007

Stabilization of long-term potentiation (LTP) depends on multiple signaling cascades linked to actin polymerization. We used one of these, involving phosphorylation of the regulatory protein cofilin, as a marker to test whether LTP-related changes occur in hippocampal synapses during unsupervised learning. Well handled rats were allowed to explore a compartmentalized environment for 30 min after an injection of vehicle or the NMDA receptor antagonist (±)-3-(2-carboxypiperazin-4-yl)propyl-1-phosphonic acid (CPP). Another group of rats consisted of vehicle-injected, home-cage controls. Vehicle-treated rats that explored the environment had 30% more spines with dense phosphorylated (p) cofilin immunoreactivity in hippocampal field CA1 than did rats in the home-cage group. The increase in pCofilin-positive spines and behavioral evidence for memory of the explored environment were both eliminated by CPP. Coimmunostaining for pCofilin and the postsynaptic density protein 95 (PSD-95) showed that synapses on pCofilin-positive spines were substantially larger than those on neighboring (pCofilin-negative) spines. These results establish that uncommon cellular events associated with LTP, including changes in synapse size, occur in individual spines during learning, and provide a technique for mapping potential engrams.
Ca2+-Permeable AMPA Receptors Regulate Growth of Human Glioblastoma via Akt Activation
Authors: Ishiuchi Shogo , Yoshida Yukari , Sugawara Kenichi , Aihara Masanori , Ohtani Toshiyuki , Watanabe Takashi , Saito Nobuhito , Tsuzuki Keisuke , Okado Haruo , Miwa Akiko , Nakazato Yoichi , Ozawa Seiji
Published: July 2007

Evidence has been accumulated that glioblastoma cells release and exploit glutamate for proliferation and migration by autocrine or paracrine loops through Ca2+-permeable AMPA-type glutamate receptors. Here, we show that Ca2+signaling mediated by AMPA receptor regulates the growth and motility of glioblastoma cells via activation of Akt. Ca2+supplied through Ca2+-permeable AMPA receptor phosphorylated Akt at Ser-473, thereby facilitating proliferation and mobility. A dominant-negative form of Akt inhibited cell proliferation and migration accelerated by overexpression of Ca2+-permeable AMPA receptor. In contrast, introduction of a constitutively active form of Akt rescued tumor cells from apoptosis induced by the conversion of Ca2+-permeable AMPA receptor to Ca2+-impermeable receptors by the delivery of GluR2 cDNA. Therefore, Akt functions as downstream effectors for Ca2+-signaling mediated by AMPA receptor in glioblastoma cells. The activation of the glutamate-AMPA receptor-Akt pathway may contribute to the high degree of anaplasia and invasive growth of human glioblastoma. This novel pathway might give an alternative therapeutic target.
ATF3 Increases the Intrinsic Growth State of DRG Neurons to Enhance Peripheral Nerve Regeneration
Authors: Seijffers Rhona , Mills Charles D. , Woolf Clifford J.
Published: July 2007

Peripheral axons of dorsal root ganglion (DRG) neurons, but not their central axons in the dorsal columns, regenerate after injury. However, if the neurons are conditioned by a peripheral nerve injury into an actively growing state, the rate of peripheral axonal growth is accelerated and the injured central axons begin to regenerate. The growth-promoting effects of conditioning injuries have two components, increased axonal growth and a reduced response to inhibitory myelin cues. We have examined which transcription factors activated by peripheral axonal injury may mediate the conditioning effect by regulating expression of effectors that increase the intrinsic growth state of the neurons. Activating transcription factor 3 (ATF3) is a prime candidate because it is induced in all injured DRG neurons after peripheral, but not central, axonal damage. To investigate if ATF3 promotes regeneration, we generated transgenic mice that constitutively express this transcription factor in non-injured adult DRG neurons. The rate of peripheral nerve regeneration was enhanced in the transgenic mice to an extent comparable to that produced by a preconditioning nerve injury. The expression of some growth-associated genes, such as SPRR1A, but not others like GAP-43, was increased in the non-injured neurons. ATF3 increased DRG neurite elongation when cultured on permissive substrates but did not overcome the inhibitory effects of myelin or promote central axonal regeneration in the spinal cordin vivo. We conclude that ATF3 contributes to nerve regeneration by increasing the intrinsic growth state of injured neurons.
Development of a Permeability Model for Palm Fruit Cake
Authors: Owolarafe Oseni K , Badmus Ganiyu A , Faborode Michael O
Published: July 2007

Investigation was carried out on the effect of processing conditions such as temperature, pressure and porosity on permeability of palm fruit cake. It was observed that increasing the temperature of the crude palm oil from 30 to 75°C, pressure from 2.88 to 3.82 kPa and porosity from 9.2 to 27.3% increases the permeability of the palm fruit cake. The statistical analysis of the effects of the processing factors on permeability indicates that temperature and porosity are significant at 99.99% while pressure was significant at 95%. A permeability model applicable to the practical palm oil expression was also developed in the study.
Rheological Properties of Cooking Creams: Effect of Freeze-Thaw Treatment
Authors: Cancela Angeles , Maceiras Rocio , Delgado-Bastidas Nathalie , Alvarez Estrella
Published: July 2007

Rheological characteristics of commercial creams were investigated at different freeze-thaw conditions. This study was carried out to determine the effect of the freeze-thaw treatment on rheological behaviour and the activation energy in different commercial creams. Freeze-thaw treatment was made at different times of frozen storage within a range from 0 to 6 weeks. For each freezing cycle, the sample was submitted to rheological measurements within range of temperature between 20 and 40° C. A rotational, concentric cylinder viscosimeter Viscotester VT550 (Germany) type Searle was used in this work. The apparent viscosity is defined as the ratio of shear stress and shear rate, which was varied between 17.8 and 445 s-1. The Power Law or Oswaltd Waele model describes well the rheological behaviour of the analyzed samples. Furthermore, in all cases sample viscosity increased when was exposed to freeze-thaw treatment with respect to the not treated sample. And other hand, the activation energy has high values; hence there is clear evidence that the rheological behaviour presents a high dependence with the temperature.
The Impact of Reputation Timing and Source on Auction Outcomes
Authors: Eaton David H
Published: July 2007

This paper uses data from electric guitar auctions on eBay to further examine the impact of reputation on the likelihood that an auction ends in a sale. It extends the existing literature by examining both the impact of the overall eBay feedback rating as well as feedback from shorter time periods. The results of this paper suggest that recent feedback, and in particular recent negative feedback, is of particular importance in explaining the likelihood that an auctioned item sells. Other feedback related factors included in this paper are measures for the source of feedback (i.e. buying or selling behavior) and whether negative feedback is product or seller related.
Family Expenditures on Child Care
Authors: Rosenbaum Dan T , Ruhm Christopher J
Published: July 2007

This study examines the child care "expenditure share," defined as child care expenses divided by after-tax income. We estimate that the average child under six years of age lives in a family that spends 4.9 percent of after-tax income on child care. However, this conceals wide variation: 63 percent of such children reside in families with no child care expenses and 10 percent are in families where the expenditure share exceeds 16 percent. The proportion of income devoted to child care is typically greater in single-parent than married-couple families but is not systematically related to a constructed measure of socioeconomic status. One reason for this is that disadvantaged families use lower cost modes and pay less per hour for given types of care. The expenditure share would be much less equal without low cost (presumably subsidized) formal care focused on needy families, as well as government tax and transfer policies that redistribute income towards them.
Energy Taxes in Three Political Economy Models
Authors: Cremer Helmuth , De Donder Philippe , Gahvari Firouz
Published: July 2007

What accounts for the existence of positive energy taxes in the US, given that such taxes are regressive and that the income distribution is skewed to the right? The traditional majority-voting equilibrium approach suggests a subsidy; thus we also look at two alternatives. These are the probabilistic-voting model and Roemer's (2001) model of political competition with the "Party Unanimity Nash Equilibrium" (PUNE) as the equilibrium solution concept. Our economic model is calibrated on the basis of the US data. The paper shows that while the majority-voting approach calls for a massive subsidy, the PUNE approach leads to huge environmental taxes. Our tentative results suggest that the probabilistic model, wherein parties assume that the proportion of unbiased voters is the same in all categories of income, comes closest to explaining the observed US energy taxes.
Construction of Sampling and Interpolating Sequences for Multi-Band Signals. The Two-Band Case
Authors: Avdonin Sergei , Bulanova Anna , Moran William
Published: July 2007

Construction of Sampling and Interpolating Sequences for Multi-Band Signals. The Two-Band Case

Recently several papers have related the production of sampling and interpolating sequences for multi-band signals to the solution of certain kinds of Wiener-Hopf equations. Our approach is based on connections between exponential Riesz bases and the controllability of distributed parameter systems. For the case of two-band signals we derive an operator whose invertibility is equivalent to the existence of a sampling and interpolating sequence, and prove the invertibility of this operator.
Falseness of the Finiteness Property of the Spectral Subradius
Authors: Czornik Adam , Jurgaś Piotr
Published: July 2007

Falseness of the Finiteness Property of the Spectral Subradius

We prove that there exist infinitely may values of the real parameter α for which the exact value of the spectral subradius of the set of two matrices (one matrix with ones above and on the diagonal and zeros elsewhere, and one matrix with α below and on the diagonal and zeros elsewhere, both matrices having two rows and two columns) cannot be calculated in a finite number of steps. Our proof uses only elementary facts from the theory of formal languages and from linear algebra, but it is not constructive because we do not show any explicit value of α that has described property. The problem of finding such values is still open.
Monitoring of Chlorine Concentration in Drinking Water Distribution Systems Using an Interval Estimator
Authors: Łangowski Rafał , Brdys Mietek
Published: July 2007

Monitoring of Chlorine Concentration in Drinking Water Distribution Systems Using an Interval Estimator

This paper describes the design of an interval observer for the estimation of unmeasured quality state variables in drinking water distribution systems. The estimator utilizes a set bounded model of uncertainty to produce robust interval bounds on the estimated state variables of the water quality. The bounds are generated by solving two differential equations. Hence the numerical efficiency is sufficient for on-line monitoring of the water quality. The observer is applied to an exemplary water network and its performance is validated by simulations.
A Family of Model Predictive Control Algorithms With Artificial Neural Networks
Authors: Ławryńczuk Maciej
Published: July 2007

A Family of Model Predictive Control Algorithms With Artificial Neural Networks

This paper details nonlinear Model-based Predictive Control (MPC) algorithms for MIMO processes modelled by means of neural networks of a feedforward structure. Two general MPC techniques are considered: the one with Nonlinear Optimisation (MPC-NO) and the one with Nonlinear Prediction and Linearisation (MPC-NPL). In the first case a nonlinear optimisation problem is solved in real time on-line. In order to reduce the computational burden, in the second case a neural model of the process is used on-line to determine local linearisation and a nonlinear free trajectory. Single-point and multi-point linearisation methods are discussed. The MPC-NPL structure is far more reliable and less computationally demanding in comparison with the MPC-NO one because it solves a quadratic programming problem, which can be done efficiently within a foreseeable time frame. At the same time, closed-loop performance of both algorithm classes is similar. Finally, a hybrid MPC algorithm with Nonlinear Prediction, Linearisation and Nonlinear optimisation (MPC-NPL-NO) is discussed.
Fuzzy Feedback Linearizing Controller and Its Equivalence With the Fuzzy Nonlinear Internal Model Control Structure
Authors: Boukezzoula Reda , Galichet Sylvie , Foulloy Laurent
Published: July 2007

Fuzzy Feedback Linearizing Controller and Its Equivalence With the Fuzzy Nonlinear Internal Model Control Structure

This paper examines the inverse control problem of nonlinear systems with stable dynamics using a fuzzy modeling approach. Indeed, based on the ability of fuzzy systems to approximate any nonlinear mapping, the nonlinear system is represented by a Takagi-Sugeno (TS) fuzzy system, which is then inverted for designing a fuzzy controller. As an application of the proposed inverse control methodology, two popular control structures, namely, feedback linearization and Nonlinear Internal Model Control (NIMC) are investigated. Moreover, the paper points out that, under some conditions, both of the control structures are equivalent and naturally implement a Smith predictor in the presence of time delays.
Evaluating the Kernighan-Lin Heuristic for Hardware/Software Partitioning
Authors: Mann Zoltán , Orbán András , Farkas Viktor
Published: July 2007

Evaluating the Kernighan-Lin Heuristic for Hardware/Software Partitioning

In recent years, several heuristics have been proposed for the hardware/software partitioning problem. One of the most promising directions is the adaptation of the Kernighan-Lin algorithm. The Kernighan-Lin heuristic was originally developed for circuit partitioning, but it has been adapted to other domains as well. Moreover, numerous improvements have been suggested so that now several variants of the original algorithm exist. The aim of this paper is to systematically evaluate the possibilities of applying the Kernighan-Lin heuristic to hardware/software partitioning. It is investigated in detail which versions of the heuristic work well in this context. Since hardware/software partitioning also has several formulations, it is also discussed how the problem formulation affects the applicability of this heuristic. Furthermore, possibilities of efficient implementations of the algorithm—by using appropriate data structures—are also presented. These investigations are accompanied by numerous empirical test results.
Applications of in Situ Hybridization Techniques in the Diagnosis of Chronic Sinusitis
Authors: Hwang Peter H. , Montone Kathleen T. , Gannon Francis H. , Senior Brent A. , Lanza Donald C. , Kennedy David W.
Published: July 2007

The clinical significance of positive bacterial cultures in chronic sinusitis is often difficult to assess. Contaminants from surface colonization of the sinus mucosa may be difficult to distinguish from true intramucosal or bone involvement. Furthermore, tissue Gram stains are frequently unable to demonstrate the presence of bacteria in tissue despite endoscopic evidence of active sinusitis. In situ hybridization (ISH) techniques using bacterial rRNA probes were applied to evaluate the presence of intramucosal and intraosseous bacteria in chronic sinusitis surgical specimens. A total of 22 specimens of chronically inflamed human ethmoid bone were evaluated by ISH and by Gram stain. In three specimens, ISH identified bacterial rRNA within sinus mucosa and mucin. Notably, in these three ISH-positive specimens, Gram stain was negative in two. No specimen showed evidence of bacterial rRNA within bone. These preliminary results suggest that in situ hybridization may be a useful adjunct to current methods of detecting microorganisms within chronically infected sinus tissue.
The Septal Mucosa Decongests with Naphazoline: A Study of Mucosal Dynamics with Sonography
Authors: Tasman Abel-Jan , Soor Angelika , Zaiss Monika , Weidauer Hagen
Published: July 2007

A new method using B-mode and power-Doppler-mode (pD) sonography for the investigation of changes in nasal mucosa swelling and perfusion was developed. The effect of naphazoline (0,25 mg/mL) on the nasal mucosa was visualized and recorded in 1-minute intervals in 40 patients. The effect of normal saline solution was studied in 27 healthy volunteers. The decongestant and normal saline were applied by flooding the anterior nasal cavity. A computer program automatically quantified pD color information. Normal saline solution induced a 4.8 ± 2.4% increase in perfusion (±SEM, n.s.) after 5 minutes. In the naphazoline group, changes in stereometry were measured on B-mode-sequences in 24 (60%) and perfusion changes in 24 participants (60%). In 16 of 40 patients (40%), both stereometry and perfusion were analyzed. After 10 minutes, the septum and inferior turbinate mucosa thickness were reduced by 17 ± 2.8% (p < 0.001) and 25 ± 2.6% (p < 0.001). Perfusion of the septum and inferior turbinate mucosa as visualized with pD-sonography decreased by 33 ± 3.3% (p < 0.001). The reduction of bloodflow induced by naphazoline as visualized with pD-sonography is within the range of perfusion changes found in LDF and Xenon clearance studies. Decongestion of the septum mucosa demonstrates erectile properties of the septum, which may contribute to the increase of nasal patency after nasal decongestion.
Normal Adult Values, Diurnal Variation, and Repeatability of Nasal Nitric Oxide Measurement
Authors: Bartley James , Fergusson Wendy , Moody Alison , Wells Athol U. , Kolbe J.
Published: July 2007

Reports of elevated nasal nitric oxide (NO) levels in allergic rhinitis suggest that nasal NO levels could be a valuable marker of upper airway inflammation, provided that the reproducibility of nasal NO measurement is acceptable. The aims of this study were to evaluate the precision with which nasal NO levels can be measured at single point in time, and to quantify within-day and between-day variation. Nasal NO was measured using a modified chemiluminiscence analyzer. Population data were normally distributed, as judged by testing for skewness and kurtosis. NO levels were not related to age or gender, and there was no evidence of diurnal variation. Sampling rates of 250 mL/minute and 500 mL/minute at a single point in time had acceptable reproducibility (coefficients of variation 10.2% and 6.6%, respectively). However, within-day variation (coefficient of variation 13.4%) and between-day variation (coefficient of variation 11.8%), at a sampling rate of 500 L/minute, were substantially higher. These findings highlight the importance of taking measurement variation into account, in the interpretation of NO levels, in clinical research and, potentially, in routine practice. In individual patients, an alteration of 20–25% in NO levels is required, to ensure that change is genuine and not ascribable to the noise of measurement.
The Effects of Adenoid Hypertrophy and Subsequent Adenoidectomy on Pediatric Nasal Airway Resistance
Authors: Dinis P. Borges , Haider Haula , Gomes Augusto
Published: July 2007

To investigate how adenoid hypertrophy and subsequent adenoidectomy affect pediatric airway resistance, we developed a prospective controlled study. Fifty children, aged 3 to 12 years, diagnosed with adenoid hypertrophy and selected for adenoidectomy, preoperatively had their nasal airway resistance assessed by active anterior rhinomanometry. Twenty-five of these children were subsequently followed up postoperatively, undergoing nasal resistance evaluations at 1 month, 3 months, 6 months, and 12 months. Another 25 children, without chronic upper airway obstruction symptoms, were enrolled as a control group, and their airway resistance was assessed in the same fashion. We concluded that the children selected for adenoidectomy, compared to the control group and before surgery, had mean resistance values up to two- to threefold higher, in both untreated and decongested nose states. Surgery was found to dramatically reduce airway resistance, but only in children under the age of seven. However, the postoperative values still tended to remain higher than the control subjects results. If in a significant number of children the operation failed in completely resolving their complaints, no preoperative rhinomanometric pattern could be found to specifically relate to a complete surgical success.
Changes in Nasal Resistance and Nasal Geometry Using Pressure and Acoustic Rhinometry in a Feline Model of Nasal Congestion
Authors: McLeod Robbie L , Mingo Garfield G. , Herczku Christine , Corboz Michel R. , Ramos Sonia I. , DeGennaro-Culver Frances , Pedersen Ole , Hey John A.
Published: July 2007

This is the first report describing the use and pharmacological characterization of nasal patency by both pressure rhinometry and acoustic rhinometry (AcR) in an experimental cat model of nasal congestion. In pressure rhinometry studies, aerosolized compound 48/80 (0.1–3.0%), a mast cell liberator, increased nasal airway resistance (NAR) 1.2 ± 0.6, 5.8 ± 0.5, 8.6 ± 1.1 and 7.9 ± 1.5 cmH2O·L/minute, respectively. Increases in NAR produced by compound 48/80 were associated with a 395% increase in histamine concentration found in the nasal lavage fluid. Pretreatment with the α-adrenoreceptor agonist, phenylpropanolamine (PPA; 0.1–3.0 mg/kg, i.v.), and the NO synthetase inhibitor, NG-nitro-L-arginine (L-NAME; 10 mg/kg, i.v.) attenuated the increases in NAR produced by compound 48/80. The histamine H1antagonist chlorpheniramine (1.0 mg/kg, i.v.) and the H2antagonist, ranitidine (1.0 mg/kg, i.v.) had no decongestant activity. Also without decongestant activity were the muscarinic antagonist atropine, the cyclooxygenase inhibitor indomethacin, and the 5-HT blocker methysergide. Aerosolized histamine (0.1–1.0%) also produced a dose dependent increase in NAR. In studies using acoustic rhinometry (AcR), intranasal application of compound 48/80 (0.1–1.0%) elicited pronounced decreases in nasal cavity volumes and minimum cross-sectional area (Amin). Pretreatment with PPA (3 mg/kg, i.v. or 10 mg/kg, p.o.) attenuated the decreases in nasal volume and Amin. The effects of topical intranasal histamine (0.1–1.0%) on nasal geometry were similar to compound 48/80. We conclude that the cat is a useful model for evaluating the pharmacological actions of potential nasal decongestants. Furthermore, we also conclude that AcR is a useful method for noninvasive assessment of nasal patency in a preclinical setting.
Human proactive aggression: association with personality disorders and psychopathy
Authors: Nouvion Sylvain O. , Cherek Don R. , Lane Scott D. , Tcheremissine Oleg V. , Lieving Lori M.
Published: July 2007

Aggressive behaviors can be divided into two categories: reactive and proactive. Reactive aggressive behaviors occur in response to a stimulus or provocation. Proactive aggressive behaviors occur without provocation and are goal directed. A number of findings have suggested that individuals displaying proactive aggression may be discerned from individuals not displaying proactive aggression on measures of personality, psychopathology and psychopathy as well as in aggressive histories and type and severity of aggressive behaviors committed. In this study, subjects were recruited from a large urban community and classified as proactive (n= 20), reactive‐only (n= 20) or nonaggressive (n= 10) based on laboratory behavioral testing. Subjects were administered a battery of questionnaires and structured interviews pertaining to personality disorders and psychopathy. It was hypothesized that proactive aggressive subjects would show greater numbers of personality disorders and have greater psychopathy relative to reactive‐only and nonaggressive subjects. These hypotheses were supported. These results suggest that proactive aggression may be identified in a laboratory‐based task, and differences between proactive and reactive‐only aggressors can be detected. Aggr. Behav. 33:552–562, 2007. © 2007 Wiley‐Liss, Inc.
A pinch or a lesion: a reconceptualization of biting consequences in mice
Authors: Litvin Yoav , Blanchard D. Caroline , Pentkowski Nathan S. , Blanchard Robert J.
Published: July 2007

Intruder and resident male colony mice exhibit an array of distinct defensive and offensive behaviors. Intruders typically show more boxing, flight, defensive sideways position, on the back position and general locomotion, while residents exhibit higher levels of attack, olfactory investigation, aggressive grooming, and biting, with a preference for dorsal bite locations. Here, analysis of bite locations on the body of the intruder mice showed that the majority of bites produced few lesions (i.e. actual puncturing of the skin) when compared to scrapes or no markings. Most bites were directed to the back of the opponent animal with very few bites directed towards the opponents' vulnerable ventrum. In particular, bites directed at the relatively hairless ventrum produced no lesions. These findings, along with previous work on mice and rats, suggest that intraspecific offense with preferred target sites for biting, facilitates an effective but largely nonwounding interaction between resident and intruder mice. Furthermore, bruise and wound analyses suggest an association between bite targets and tissue damage. The preference for specific bite locations may be complimented by a differential intensity of attack, with the back attracting the strongest bites and the ventrum the weakest. This apparent nonwounding fighting pattern contradicts the current evaluation of rodent wounding severity in this paradigm and can therefore refine the usage of this model and of the protocols associated with it. Aggr. Behav. 33:545–551, 2007. © 2007 Wiley‐Liss, Inc.
Two‐fluid model for particle‐turbulence interaction in a backward‐facing step
Authors: Mohanarangam K. , Tu J. Y.
Published: July 2007

Particle‐turbulence interaction for dilute gas‐particle flows over a backward‐facing step geometry is numerically investigated. An Eulerian two‐fluid model with additional turbulence transport equations for particles is employed in this investigation. RNG based k‐ε model is used as the turbulent closure with additional transport equations solved, to better represent the combined gas‐particle interactions. Two different particle classes with same Stokes number and varied particle Reynolds number are considered in this study. The turbulence modulation of the carrier phase in the presence of the dispersed particulate phase is simulated and compared against the experimental data. However prior to this endeavour, the simulated flow field is validated for mean streamwise velocities and fluctuations for both the phases. Despite the fact that the two particles used in this study share the same Stokes number their behavior is found to be considerably different in the turbulent flow field, which basically underlines the fact that the Stokes number alone is not enough to fully describe the behavior of particles, thereby, herein particle Reynolds number is also investigated to fully understand their behavior. Two other turbulence modulation models were also tested against our own formulation, and our model was found to compare better with the experimental findings. © 2007 American Institute of Chemical Engineers AIChE J, 2007
Local hydrodynamics modeling of a gas–liquid–solid three‐phase bubble column
Authors: Jia Xiaoqiang , Wen Jianping , Zhou Haoli , Feng Wei , Yuan Qing
Published: July 2007

A three‐dimensional (3D) transient model was developed to simulate the local hydrodynamics of a gas–liquid–solid three‐phase bubble column using the computational fluid dynamic method, where the multiple size group model was adopted to determine the size distribution of the gas bubbles. Model simulation results, such as the local time‐averaged gas holdups and axial liquid velocities, were validated by experimental measurements under varied operating conditions, e.g., superficial gas velocities and initial solid loadings at different locations in the three‐phase bubble column. Furthermore, the local transient hydrodynamic characteristics, such as gas holdups, liquid velocities, and solid holdups, as well as gas bubble size distribution were predicted reasonably by the developed model for the dynamic behaviors of the three‐phase bubble column. © 2007 American Institute of Chemical Engineers AIChE J, 2007
Modeling blowdown of pipelines under fire attack
Authors: Mahgerefteh Haroun , Abbasi Muhammad Umar
Published: July 2007

The development of a mathematical model for simulating the blowdown of pressurized hydrocarbon conveying pipelines under fire attack is described. The model is based on the resolution of the conservation equations using the method of characteristics. It accounts for real fluid behavior, pipeline mechanical strength, as well as phase and flow dependent transient heat transfer effects, and frictional pressure losses. Failure is assumed to occur when any one of the simulated triaxial thermal and pressure stresses in the pipeline wall exceed its ultimate tensile strength. The application of the model to a hypothetical example involving localized fire attack on an isolated natural gas pipeline reveals that the pipeline fails because of large thermal stresses on the outer surface in addition to the internal pressure stresses. The efficacy of emergency depressurization using different diameter relief valves as a means of protecting the pipeline mechanical integrity during fire attack is also quantitatively investigated. © 2007 American Institute of Chemical Engineers AIChE J, 2007
No evidence for myocardial iron overload in multitransfused patients with myelodysplastic syndrome using cardiac magnetic resonance T2* technique
Authors: Konen Eli , Ghoti Husam , Goitein Orly , Winder Asher , Kushnir Tammi , Eshet Yael , Rachmilewitz Eliezer
Published: July 2007

The method of cardiovascular T2* magnetic resonance imaging (MRI) allows in vivo estimation of iron in the heart and liver and was used to measure the degree of iron overload in 10 transfused MDS patients (average 90 blood units) and in 3 patients with congenital hemolytic anemia. In all MDS patients iron overload was found in the liver but not in the heart. Patients with congenital anemias had iron in both organs despite iron chelation. It is possible that in MDS more time and more transfusions are required to induce iron accumulation in the myocardium. Therefore, cardiac MRI may serve as a diagnostic tool to assess if and when iron chelation is indicated. Am. J. Hematol., 2007. © 2007 Wiley‐Liss, Inc.
Remission of lymphoma after withdrawal of methotrexate in rheumatoid arthritis: Relationship with type of latent Epstein‐Barr virus infection
Authors: Miyazaki Takuya , Fujimaki Katsumichi , Shirasugi Yukari , Yoshiba Fumiaki , Ohsaka Manabu , Miyazaki Koji , Yamazaki Etsuko , Sakai Rika , Tamaru Jun‐ichi , Kishi Kenji , Kanamori Heiwa , Higashihara Masaaki , Hotta Tomomitsu , Ishigatsubo Yoshiaki
Published: July 2007

Rheumatoid arthritis (RA) is associated with an increased risk of developing lymphoma. Although the pathogenesis is still unclear, the increased risk appears to be related to the high inflammatory activity of RA, immunosuppressive agents, or Epstein‐Barr virus (EBV) infection. We investigated the relationship between EBV latent infection and methotrexate (MTX)‐associated lymphoma in RA patients. Nine patients were diagnosed with non‐Hodgkin's lymphoma (NHL) during MTX treatment for RA in a multicenter study. The pathologic findings were consistent with diffuse large B‐cell lymphoma in 8 patients and peripheralT‐cell lymphoma, unspecified in 1. EBV infection was detected in 3 patients by in situ hybridization. Among all 9 patients who were initially treated by MTX withdrawal alone, 2 obtained spontaneous complete response (CR), 1 had partial response, 2 had stable disease (SD), and 4 had progressive disease. Both patients who had a CR and 1 who had SD were positive for EBV. Further examination of the latent EBV infection patterns revealed that 2 patients who obtained a CR had latency Type III, and the other with SD had latency Type II. These results demonstrate that immunodeficiency caused by MTX treatment is associated with the development of EBV‐related NHL in RA patients. In patients who were treated by MTX for RA and developed NHL, remission can be observed following MTX withdrawal especially in NHL with latency Type III EBV infection. The analysis of EBV infection, including the latency types, is useful to decide the optimum therapeutic strategy. Am. J. Hematol., 2007. © 2007 Wiley‐Liss, Inc.
Increased cerebral blood flow after leukapheresis for acute myelogenous leukemia
Authors: Kasner Margaret T. , Laury Adrienne , Kasner Scott E. , Carroll Martin , Luger Selina M.
Published: July 2007

Leukapheresis is often considered in the management of acute myelogenous leukemia (AML) with hyperleukocytosis and its sequelae, including myocardial infarction, pulmonary complications, and stroke. It is utilized on the assumption that leukapheresis improves blood rheology. We present a woman with AML and a history of meningioma encasing her left internal carotid artery. She presented with hyperleukocytosis and symptoms of ischemia. As her white blood cell continued to rise despite initiation of hydroxyurea therapy, she underwent leukapheresis emergently. Transcranial Doppler ultrasound demonstrated increased flow velocities in the left internal carotid and the right middle cerebral arteries, which normalized after leukapheresis. This is the first documentation that leukapheresis, in combination with hydroxyurea, improves cerebral hemodynamics in a patient with AML. Am. J. Hematol., 2007. © 2007 Wiley‐Liss, Inc.
Exacerbation of experimental autoimmune encephalomyelitis after withdrawal of phenytoin and carbamazepine
Authors: Black Joel A. , Liu Shujun , Carrithers Michael , Carrithers Lisette M. , Waxman Stephen G.
Published: July 2007

Objective

In vitro observations and studies in murine experimental autoimmune encephalomyelitis (EAE) have shown protective effects of sodium channel blockers on central nervous system axons and improved clinical status when treatment is continued throughout the period of observation. Several clinical studies of sodium channel blockers are under way in patients with multiple sclerosis. Here we asked whether a protective effect would persist after withdrawal of a sodium channel blocker.

Methods

We studied a mouse model of myelin oligodendrocyte glycoprotein–induced EAE treated with phenytoin or carbamazepine.

Results

Both phenytoin and carbamazepine significantly improved the clinical course of the disease. Withdrawal of phenytoin resulted in acute exacerbation, accompanied by a significantly increased inflammatory infiltrate within the central nervous system and the death of nearly 60% of EAE mice. There were no clinical worsening or deaths in control mice after withdrawal of phenytoin. Withdrawal of carbamazepine led to acute worsening of EAE symptoms, increased inflammatory infiltrate, and was associated with the death of 8% of mice.

Interpretation

These results, together with results showing effects of sodium channel blockers in immune cells, raise questions about the long‐term effects of sodium channel blockers in neuroinflammatory disorders, and suggest that clinical studies of sodium channel blockers in these disorders should be planned carefully. Ann Neurol 2007
Polyurethane composites based on oil palm empty fruit bunches: Effect of isocyanate/hydroxyl ratio and chemical modification of empty fruit bunches with toluene diisocyanate and hexamethylene diisocyanate on mechanical properties
Authors: Rozman H. D. , Ahmad Hilme K. R. , Abubakar A.
Published: July 2007

This study focuses on the effect of isocyanate (NCO)/hydroxyl (OH) group ratios and chemical modification of oil palm empty fruit bunches (EFBs) with toluene diisocyanate (TDI) and hexamethylene diisocyanate (HMDI) on the mechanical properties of EFB–polyurethane (PU) composites. The tensile, flexural, and impact properties are affected by the NCO/OH ratios. The tensile strengths, flexural strengths, and toughness increase as the NCO/OH increases; however, the modulus decreases. The reduction in the modulus is attributable to the increased flexibility of the PU linkages. Chemical modification of the EFBs increases the tensile strength, flexural strength, and toughness; however, the modulus is lowered as the percentage of treated EFB is increased. Impact strength results show that the strength increases as the NCO/OH ratio is increased. At NCO/OH ratios of 1.0 and 1.1, the composites with HMDI‐treated fibers exhibit higher impact strength than those with TDI‐treated and untreated fibers, respectively. This may be due to the longer and more flexible chain length of HMDI as compared to TDI, which enables the composites to absorb more energy before failure. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Studies of precipitated polymerization of acrylamide with quaternary ammonium cationic comonomer in potassium citrate solution
Authors: Li Gang , Yang Chao , He Yangang , Yang Fang , Yu Xueqing
Published: July 2007

Copolymer particles consisting of acrylamide (AM) and cationic comonomer 2‐methyl acryloyloxyethyl trimethyl ammonium chloride (DMC) were prepared by precipitation polymerization in an solution of potassium citrate using ammonium persulfate ((NH4)2S2O8) and sodium sulfite (Na2SO3) as an initiator. The product poly(acrylamide‐2‐methyl acryloyloxyethyl trimethyl ammonium chloride) [Poly(DMC‐AM)] is a water‐soluble cationic polyelectrolyte. The solubility of DMC, AM and Poly(DMC‐AM) in potassium citrate solution were measured, combined with the theory of solubility parameter, and the experiment results indicate that the solubility of DMC and AM is much higher than that of Poly(DMC‐AM), and also the mechanism of copolymer precipitated in salt solution was discussed. The factors influencing the conversion of comonomers were examined, such as salt mass fraction, polymerization temperature, monomers mass fraction, initiator mass fraction, and so on. The results of experiments indicate that the best conditions are salt mass fraction = 57%, monomers mass fraction = 3%, m(DMC) : m(AM) = 3 : 1, initiator mass fraction = 0.08%, polymerization temperature = 50°C, reaction time = 2 h, and the conversion is 86.4%. And the qualitative analysis experimental method for copolymer by infrared absorption spectrum show that [Poly(DMC‐AM)] was successfully synthesized by precipitation polymerization. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
NR/PP thermoplastic vulcanizates: Selection of optimal peroxide type and concentration in relation to mixing conditions
Authors: Thitithammawong A. , Nakason C. , Sahakaro K. , Noordermeer J. W. M.
Published: July 2007

Thermoplastic vulcanizates (TPVs) from natural rubber (NR) and polypropylene (PP) were studied, prepared by dynamic vulcanization during melt mixing, using various peroxides to crosslink the rubber phase. The objective was to find a proper balance between degree of crosslinking of the rubber and degradation of the PP‐phase, and the tendency of the peroxide to form smelly by‐products, in particular acetophenone. Four types of peroxides were investigated: 2,5‐dimethyl‐2,5‐di(tert‐butyl‐peroxy) hexyne‐3 (DTBPHY), 2,5‐dimethyl‐2,5‐di(tert‐butyl‐peroxy) hexane (DTBPH), di(tert‐butylperoxyisopropyl) benzene (DTBPIB), and dicumyl peroxide (DCP), at two mixing temperatures: 160 and 180°C for a 60/40 NR/PP TPV. The maximum and final mixing torques are clearly related to the intrinsic decomposition temperature of the particular peroxide used, where DCP and DTBPIB turn out to be effective at 160°C, whereas the other two require a higher temperature of 180°C. The best mechanical properties, tensile strength, elongation at break and compression set are obtained at lower mixing temperature with DCP and DTBPIB, presumably due to less degradation of the NR and PP. Unfortunately, these two peroxides form more smelly by‐products than DTBPHY and DTBPH. Dependent on the requirements of the pertinent application, a balanced selection needs to be made between the various factors involved to obtain an optimal product performance of these NR/PP TPVs. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Effect of clay on mechanical and gas barrier properties of blown film LDPE/clay nanocomposites
Authors: Arunvisut Supong , Phummanee Sutthipat , Somwangthanaroj Anongnat
Published: July 2007

Low density polyethylene (LDPE)/clay nanocomposites, which can be used in packaging industries, were prepared by melt‐mix organoclay with polymer matrix (LDPE) and compatibilizer, polyethylene grafted maleic anhydride (PEMA). The pristine clay was first modified with alkylammonium salt surfactant, before melt‐mixed in twin screw extruder attached to blown‐film set. D‐spacing of clay and thermal behavior of nanocomposites were characterized by Wide‐Angle X‐ray Diffraction (WAXD) and differential scanning calorimetry (DSC), respectively. WAXD pattern confirmed the increase in PEMA contents exhibited better dispersion of clay in nanocomposites. Moreover, DSC was reported the increased PEMA contents caused the decrease in degree of crystallinity. Mechanical properties of blown film specimens were tested in two directions of tensile tests: in transverse tests (TD tests) and in machine direction tests (MD tests). Tensile modulus and tensile strength at yield were improved when clay contents increased because of the reinforcing behavior of clay on both TD and MD tests. Tensile modulus of 7 wt % of clay in nanocomposite was 100% increasing from neat LDPE in TD tests and 17% increasing in MD tests. However, elongation at yield decreased when increased in clay loading. Oxygen permeability tests of LDPE/clay nanocomposites also decreased by 24% as the clay content increased to 7 wt %. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Effect of silane‐coupling agents on interfacial properties of CF/PI composites
Authors: He J. M. , Huang Y. D.
Published: July 2007

In this article, to form a structure‐controlled interface, carbon fiber (CF) surfaces were first activated by plasma technique and then hydroxylated by LiAlH4 treatment, and then were reacted with a suit of silane‐coupling agents terminated with desired functional groups to form thin films, which further reacted with polyimide (PI) resin to generate a strong adhesion interface. The morphology, structure, and composition of CF surfaces before and after treatment were investigated by atomic force microscopy (AFM), Fourier transform infrared spectroscopy (FTIR), and X‐ray photoelectron spectroscopy (XPS), respectively. The results of FTIR and XPS analysis showed that silane‐coupling agents were successfully chemisorbed onto the CF surfaces by the hydrolysis and condensation reactions. The interfacial shear strength of the CF/PI microcomposites was evaluated by the microbond technique. The results showed that the types of the interfacial functional groups, especially the vinyl end groups in vinyltriethoxysilane (VS), which can react with PI resin, had very significant influence on the improvement of the interfacial adhesion properties of composites. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007