bluuebunny/crossref_metadata_2025 huggingface dataset:
Inverted First‐Person Authority
Authors: McGinn Colin
Published: March 2005

It is often assumed that mental states must be known introspectively just as material objects must be known perceptually, and that this mode of knowing is especially authoritative; this chapter controverts this assumption. It is argued that a subject might introspect physical facts and perceive mental ones; and that a strong conception of the first-person authority of introspection – non-criterial, non-inferential, direct, infallible, incorrigible, certain – might apply instead to perception. The implications of the logical possibility of such an inverted subject for scepticism and the mind-body problem are discussed. The tension between the view of this chapter, which would make it possible for a subject to have a concept of pain without having introspective acquaintance with it, and the view that this is impossible is discussed.
What are the Options?
Authors: Dancy Jonathan
Published: March 2005

An introductory chapter that maps the possible views about the relation between moral thought and moral principles, showing how extreme the particularist position is. Particularism is contrasted with Rossian intuitionism and its use of prima facie principles; and the particularist account of moral reasoning is contrasted with non-monotonic theories, and with the views of Kagan and Scanlon.
Holism and its Consequences
Authors: Dancy Jonathan
Published: March 2005

Gives the best argument for holism in the theory of reasons, and then considers how best to establish ethical particularism on that basis. Also considers various ways of accepting holism without going so far as the particularist wants to go.
Representation as Responsiveness
Authors: Kuper Andrew
Published: March 2005

Develops a theory of representation that can guide the democratization of societies of great and even global scope. Kuper elucidates the institutional conditions necessary for (1) good judgements about interests to be made, (2) by adequately informed and capable agents, (3) who are empowered and constrained to act on such judgements responsibly. He argues that elections, competitive party politics, the classical tripartite separation of powers, media, and civil society are insufficient mechanisms for securing such substantive representation. He proposes an alternative institutional configuration, a new ‘plurality of powers’ that supplements and transforms these mechanisms. Among Kuper’s proposals for new institutions are: ‘advocacy and accountability agencies’ that will reduce power imbalances; a global ‘Charter of Obligations’ that will reduce bureaucracy; and a vision of ‘responsive global citizenship’ that will reduce citizen passivity. These innovations will enable citizens to exercise greater control, and enable representatives to act more effectively, than under a system of states.
Ophthalmomyiasis (interna posterior) of the posterior segment and central nervous system myiasis: Cuterebra spp. in a cat
Authors: Wyman Milton , Starkey Robert , Weisbrode Steven , Filko Dawn , Grandstaff Rachel , Ferrebee Edna
Published: March 2005

A unilateral ophthalmomyiasis posterior in a 5‐year‐old female spayed Domestic Long‐haired cat of a third or fourth stage instar Cuterebra spp. larvae is reported. The cat was presented for depression and anorexia. The organism was found on physical examination at presentation. The cat was euthanized because of the worsening systemic condition. The larva was demonstrated by histopathology with coagulation necrosis and hemorrhage of the optic nerve, retina and choroid, and anterior uveitis. No significant cerebrum and anterior brain stem lesions were found.
Bilateral nodular lymphocytic conjunctivitis in a horse
Authors: Stoppini Riccardo , Gilger Brian C. , Malarkey David E. , Ratto Alessandra , Brigati Giampiero
Published: March 2005

A Russian jumper horse presented because of an ocular perilimbal conjunctival mass and, on clinical examination, two bilateral conjunctival masses were found, of different size and conformation. Attempts at complete excision of the left eye mass and excisional biopsy of the right eye mass were performed. The left eye mass recurred rapidly, but resolved completely after topical corticosteroid therapy. The two lesions had similar histopathologic features, characterized by focal, chronic, primarily lymphocytic conjunctivitis with follicular lymphoid hyperplasia. Special histopathologic staining techniques (Gomori methenamine silver and acid fast stains) and immunohistochemistry (for CD3, BLA36 and lysozyme) failed to reveal any etiologic agents and indicated an inflammatory lesion composed of a heterogeneous population of lymphocytes and macrophages (nodular lymphocytic conjunctivitis). The lesions were indistinguishable, clinically and behaviorally, from what has been reported as ‘conjunctival pseudotumor’ in the horse. Equine conjunctival pseudotumor/nodular lymphocytic conjunctivitis has been reported to be unilateral and have a good prognosis after partial or complete surgical excision. This is the first reported case of bilateral nodular lymphocytic conjunctivitis in a horse and for which surgical excision alone was not curative.
Transonic and Low Supersonic Flow Losses of Two Steam Turbine Blades at Large Incidences
Authors: Li S.-M. , Chu T.-L. , Yoo Y.-S. , Ng W. F.
Published: March 2005

A linear cascade experiment was conducted to investigate transonic and low supersonic flow losses of two nozzle blades for the steam turbines. In the experiment, flow incidences were changed from −34° to 35° and exit Mach numbers were varied from 0.60 to 1.15. Tests were conducted at Reynolds numbers between 7.4×105 and 1.6×106. Flow visualization techniques, such as shadowgraph, Schlieren, and surface color oil were used to document the flows. Measurements were made by using downstream traverses with Pitot probe, upstream total pressure probe, and sidewall static pressure taps. The losses were found to be rather constant at subsonic flows. At transonic and low supersonic flows, the losses increased steeply. The maximum relative increase of the losses was near 700% when the Mach numbers increased from 0.6 to 1.15. However, the maximum relative increase of the losses was only about 100% due to very large variation of incidences. It is important to note that the effect of Mach numbers on losses was much greater than that due to the very large incidences for the transonic and low supersonic flows. A frequently used loss correlation in the literature is found not suitable to predict the losses of the tested blades for the transonic and low supersonic flows. From the current experimental data and some data in the literature, a new correlation for the shock related losses is proposed for transonic and low supersonic flows of turbine cascades. Comparison is made among the existing correlation and the new correlation, as well as the data of the current two cascades and other three turbine cascades in the literature. Improved agreement with the experimental data of the five cascades is obtained by using the new correlation as compared with the prediction by using the frequently used loss correlation in the literature.
Added Mass of an Oscillating Hemisphere at Very-Low and Very-High Frequencies
Authors: Storti Mario A. , D’Elı´a Jorge
Published: March 2005

A floating hemisphere under forced harmonic oscillation at very-low and very-high frequencies is considered. The problem is reduced to an elliptic one, that is, the Laplace operator in the exterior domain with Dirichlet and Neumann boundary conditions. Asymptotic values of the added mass are found with an analytic prolongation for the surge mode, and with a seminumerical computation with spherical harmonics for the heave one. The general procedure is based on the use of spherical harmonics and its derivation is based on a physical insight rather than a mathematical one. This case can be used to test the accuracy achieved by numerical codes based on other formulations as finite or boundary elements.
Numerical Simulation of Incompressible Laminar Flow over Three-Dimensional Rectangular Cavities
Authors: Yao H. , Cooper R. K. , Raghunathan S.
Published: March 2005

This paper presents results of investigations of unsteady incompressible flow past three-dimensional cavities, where there is a complex interaction between the external flow and the recirculating flow inside the cavity. A computational fluid dynamics approach is used in the study. The simulation is based on the solution of the unsteady Navier-Stokes equations for three-dimensional incompressible flow by using finite difference schemes. The cavity is assumed to be rectangular in geometry, and the flow is assumed to be laminar. Typical results of computation are presented, showing the effects of the Reynolds number, cavity geometry, and inflow condition on the cavity flow fields. The results show that high Reynolds numbers, with deep cavity and shallow cavity flows can become unsteady with Kelvin-Helmholtz instability oscillations and exhibiting a three-dimensional nature, with Taylor-Go¨rtler longitudinal vortices on the floor and longitudinal vortex structures on the shear layer. At moderate Reynolds numbers the shallow cavity flow is more stable than deep cavity flows. For a given Reynolds number the flow structure is affected by the thickness of the inflow boundary layer with a significant interaction between the external flow and the recirculating flow inside the cavity.
Combined Controller-Observer Design for Uncertain Time Delay Systems With Application to Engine Idle Speed Control
Authors: Bengea Sorin C. , Li Xiaoqiu , DeCarlo R. A.
Published: March 2005

This paper sets forth two approaches for a combined controller-observer design procedure for a class of uncertain time delay systems. The first procedure uses a delay-independent LMI (linear matrix inequality) formulation that sets forth sufficient conditions for the existence of appropriate feedback and observer matrices that guarantee asymptotic stability of the system-error dynamic combination. The second procedure generates a similar delay-dependent LMI. Standard toolboxes can be used to generate solutions to the LMIs when solutions exist. The observer-control design techniques are applied to an internal combustion (IC) engine idle speed control problem; simulation results demonstrate the effectiveness of the proposed techniques.
Recovery of Signals Distorted by Sensor Nonlinearity
Authors: Suranthiran Sugathevan , Jayasuriya Suhada
Published: March 2005

Considered in this paper is a framework for addressing sensor issues that are related to nonlinearity. When a signal is picked up by a nonlinear sensor, it is often the case that the high amplitude part of the signal is distorted by nonlinearity and the low amplitude part is indistinguishable from noise. The distorted output or sensed signal may no longer represent the original input signal due to the presence of high and low frequency foreign spikes in its frequency spectrum. This situation poses a challenging problem: Would it be possible to uniquely extract the original information from the distorted output? A treatment of this problem is given and it is shown that unique signal recovery is possible when the nonlinear characteristics of the sensor satisfy certain requirements. Based on the analysis, an algorithm is developed to recover finite length signals and its validity and efficiency are demonstrated by simulation results. When the sensor model is not available, it is shown how a model identification scheme may be incorporated into the developed scheme. Experiments performed on a physical sensor support the proposed recovery scheme.
New Adaptive Mode of Operation for MEMS Gyroscopes
Authors: Park Sungsu , Horowitz Roberto
Published: March 2005

This paper presents a new adaptive operation strategy that can identify and, in an adaptive fashion, compensate for most fabrication defects and perturbations affecting the behavior of a MEMS z-axis gyroscope. The convergence and resolution analysis presented in the paper shows that the proposed adaptive controlled scheme offers several advantages over conventional modes of operation. These advantages include a larger operational bandwidth, absence of zero-rate output, self-calibration and a large robustness to parameter variations, which are caused by fabrication defects and ambient conditions.
Simultaneous Optimal Distribution of Lateral and Longitudinal Tire Forces for the Model Following Control
Authors: Mokhiamar Ossama , Abe Masato
Published: March 2005

This paper presents a proposed optimum tire force distribution method in order to optimize tire usage and find out how the tires should share longitudinal and lateral forces to achieve a target vehicle response under the assumption that all four wheels can be independently steered, driven, and braked. The inputs to the optimization process are the driver’s commands (steering wheel angle, accelerator pedal pressure, and foot brake pressure), while the outputs are lateral and longitudinal forces on all four wheels. Lateral and longitudinal tire forces cannot be chosen arbitrarily, they have to satisfy certain specified equality constraints. The equality constraints are related to the required total longitudinal force, total lateral force, and total yaw moment. The total lateral force and total moment required are introduced using the model responses of side-slip angle and yaw rate while the total longitudinal force is computed according to driver’s command (traction or braking). A computer simulation of a closed-loop driver-vehicle system subjected to evasive lane change with braking is used to prove the significant effects of the proposed optimal tire force distribution method on improving the limit handling performance. The robustness of the vehicle motion with the proposed control against the coefficient of friction variation as well as the effect of steering wheel angle amplitude is discussed.
Customized Wavelet for Bearing Defect Detection
Authors: Holm-Hansen Brian T. , Gao Robert X. , Zhang Li
Published: March 2005

This paper presents a new, structural dynamics-based wavelet transformation technique for bearing defect detection. Specifically, a customized wavelet was developed analytically, using the scaling function derived from the actual impulse response of a ball bearing. Experiments under various loading conditions have confirmed that the customized wavelet provides a better match to the defect-induced signals of the bearing than a standard wavelet commonly used in the literature and is, thus, more effective in detecting bearing structural defects.
Estimation, Control and Optimization of Curing in Thick-Sectioned Composite Parts
Authors: Parthasarathy Sanjay , Mantell Susan C. , Stelson Kim A.
Published: March 2005

A nonlinear model-based control method is proposed and validated for controlling, estimating and optimizing the cure in composite parts. During the cure, the exothermic reaction causes temperature gradients through the thickness that can lead to a nonuniform cure and high residual stress. A predictive control and optimization approach is proposed to ensure that temperature gradients are kept within acceptable limits and the cure state is fairly uniform, regardless of the part thickness. A reduced order process model is derived and used to formulate a dynamic inversion controller. A nonlinear observer is constructed to estimate the unknown temperature and cure states within the composite. An on-line optimizer determines the maximum allowable heating rate. The optimizer is run at discrete intervals throughout the process to account for process and part variability. The control, estimation and optimization algorithms were validated through a series of simulations and experiments of composite parts cured in a press. Parts that were cured with the proposed control method were compared with parts cured following a manufacturer’s recommended cure cycle. The results demonstrate the success of the proposed control method in achieving uniform temperature and cure, and in decreasing the residual stress, without increasing cycle time.
Track Tension Controller Design and Experimental Evaluation in Tracked Vehicles
Authors: Huh Kunsoo , Chung Chung Choo , Kim I. M. , Suh Mun-suk
Published: March 2005

Track tension is closely related to the maneuverability of tracked vehicles and the durability of their tracks and suspension systems. The tension needs to be maintained at an optimum level throughout the maneuver in order to minimize the excessive load on the tracks and to prevent track peeloff from the sprocket. In this paper, a track tension control system is developed for tracked vehicles which are subject to various maneuvering tasks. It consists of track tension estimator, track tension controller, and hydraulic unit. The tension around the idler and sprocket is estimated in real time, respectively. Using the estimated track tension and considering the highly nonlinear vehicle characteristics, a fuzzy logic controller is designed in order to control the track tension in the vehicles. The performance of the proposed tension control system is verified through simulation and experimental field tests.
A beamforming video recorder for integrated observations of dolphin behavior and vocalizations (L)
Authors: Ball Keenan R. , Buck John R.
Published: March 2005

In this Letter we describe a beamforming video recorder consisting of a video camera at the center of a 16 hydrophone array. A broadband frequency-domain beamforming algorithm is used to estimate the azimuth and elevation of each detected sound. These estimates are used to generate a visual cue indicating the location of the sound source within the video recording, which is synchronized to the acoustic data. The system provided accurate results in both lab calibrations and a field test. The system allows researchers to correlate the acoustic and physical behaviors of marine mammals during studies of social interactions.
Reflection and transmission by randomly spaced elastic cylinders in a fluid slab-like region
Authors: Le Bas Pierre-Yves , Luppé Francine , Conoir Jean-Marc
Published: March 2005

An extension of Fikioris and Waterman’s formalism is developed in order to describe both the reflection and transmission from a slab-like fluid region in which elastic cylindrical scatterers are randomly placed. The dispersion equation of the coherent wave inside the slab must be solved numerically. For solid cylinders, there is only one solution corresponding to a mean free path of the coherent wave larger than one wavelength. In that case, the slab region may be described as an effective dissipative fluid medium, and its reflection and transmission coefficients may be formally written as those of a fluid plate. For thin hollow shells, a second solution of the dispersion equation is found, at concentrations large enough for the shells to be coupled via the radiation of a circumferential Scholte–Stoneley A wave on each shell. This occurs at a few resonance frequencies of the shells. At those frequencies, then, two different coherent waves propagate in the slab, and it can no longer be considered a dissipating fluid slab.
Glottal open quotient in singing: Measurements and correlation with laryngeal mechanisms, vocal intensity, and fundamental frequency
Authors: Henrich Nathalie , d’Alessandro Christophe , Doval Boris , Castellengo Michèle
Published: March 2005

This article presents the results of glottal open-quotient measurements in the case of singing voice production. It explores the relationship between open quotient and laryngeal mechanisms, vocal intensity, and fundamental frequency. The audio and electroglottographic signals of 18 classically trained male and female singers were recorded and analyzed with regard to vocal intensity, fundamental frequency, and open quotient. Fundamental frequency and open quotient are derived from the differentiated electroglottographic signal, using the DECOM (DEgg Correlation-based Open quotient Measurement) method. As male and female phonation may differ in respect to vocal-fold vibratory properties, a distinction is made between two different glottal configurations, which are called laryngeal mechanisms: mechanism 1 (related to chest, modal, and male head register) and mechanism 2 (related to falsetto for male and head register for female). The results show that open quotient depends on the laryngeal mechanisms. It ranges from 0.3 to 0.8 in mechanism 1 and from 0.5 to 0.95 in mechanism 2. The open quotient is strongly related to vocal intensity in mechanism 1 and to fundamental frequency in mechanism 2.
Horizontal refraction of acoustic signals retrieved from North Pacific Acoustic Laboratory billboard array data
Authors: Voronovich A. G. , Ostashev V. E. , Colosi J. A. , Cornuelle B. D. , Dushaw B. D. , Dzieciuch M. A. , Howe B. M. , Mercer J. A. , Munk W. H. , Spindel R. C. , Worcester P. F. ,   The NPAL Group
Published: March 2005

In 1998–1999, a comprehensive low-frequency long-range sound propagation experiment was carried out by the North Pacific Acoustic Laboratory (NPAL). In this paper, the data recorded during the experiment by a billboard acoustic array were used to compute the horizontal refraction of the arriving acoustic signals using both ray- and mode-based approaches. The results obtained by these two approaches are consistent. The acoustic signals exhibited weak (if any) regular horizontal refraction throughut most of the experiment. However, it increased up to 0.4 deg (the sound rays were bent towards the south) at the beginning and the end of the experiment. These increases occurred during midspring to midsummer time and seemed to reflect seasonal trends in the horizontal gradients of the sound speed. The measured standard deviation of the horizontal refraction angles was about 0.37 deg, which is close to an estimate of this standard deviation calculated using 3D modal theory of low-frequency sound propagation through internal gravity waves.
Analysis of multipath acoustic field variability and coherence in the finale of broadband basin-scale transmissions in the North Pacific Ocean
Authors: Colosi John A. , Baggeroer Arthur B. , Cornuelle Bruce D. , Dzieciuch Matthew A. , Munk Walter H. , Worcester Peter F. , Dushaw Brian D. , Howe Bruce M. , Mercer James A. , Spindel Robert C. , Birdsall Theodore G. , Metzger Kurt , Forbes Andrew M. G.
Published: March 2005

The statistics of low-frequency, long-range acoustic transmissions in the North Pacific Ocean are presented. Broadband signals at center frequencies of 28, 75, and 84 Hz are analyzed at propagation ranges of 3252 to 5171 km, and transmissions were received on 700 and 1400 m long vertical receiver arrays with 35 m hydrophone spacing. In the analysis we focus on the energetic “finale” region of the broadband time front arrival pattern, where a multipath interference pattern exists. A Fourier analysis of 1 s regions in the finale provide narrowband data for examination as well. Two-dimensional (depth and time) phase unwrapping is employed to study separately the complex field phase and intensity. Because data sampling occured in 20 or 40 min intervals followed by long gaps, the acoustic fields are analyzed in terms of these 20 and 40 min and multiday observation times. An analysis of phase, intensity, and complex envelope variability as a function of depth and time is presented in terms of mean fields, variances, probability density functions (PDFs), covariance, spectra, and coherence. Observations are compared to a random multipath model of frequency and vertical wave number spectra for phase and log intensity, and the observations are compared to a broadband multipath model of scintillation index and coherence.
Distribution of wave packet sizes in microbarom wave trains observed in Alaska
Authors: Olson John V. , Szuberla Curt A. L.
Published: March 2005

This work reports on a study of the distribution of wave packet sizes contained in intervals of continuous microbarom activity. Microbaroms are a class of atmospheric infrasound that is characterized by narrow-band, nearly sinusoidal, waveforms with periods near 5 s. They are known to be generated by marine storms, presumably through a nonlinear interaction of surface waves, however the detailed analysis of the process is still incomplete. The data analyzed were obtained using the University of Alaska infrasound array of four microphones located in central Alaska. Because of the narrow-band feature of the microbarom signals, the Hilbert transform is applicable as a method for finding phase breaks in the signal. The phase breaks are interpreted as the demarcation of the boundaries of wave packets. When applied to long sequences of microbaroms a broad distribution of packet lengths is found that diminishes monotonically with length and has a mean near 10 cycles and a variance nearly as large. The distribution function decreases exponentially with packet length. The distribution of packet sizes is influenced by the presence of multiple sources and multiple propagation paths between the sources and the sensor array. Identification of individual packets should open the way to a more detailed analysis of microbarom wave trains. After separating the wave train into individual wavelets the intermicrophone correlation is estimated as a function of microphone separation. As has been observed in earlier microbarom studies, a decrease in correlation was observed for microphone pairs orthogonal to the direction of propagation when compared to correlations between microphones spaced along the direction of wave propagation.
North Pacific Acoustic Laboratory
Authors: Worcester Peter F. , Spindel Robert C.
Published: March 2005

A series of long-range acoustic propagation experiments have been conducted in the North Pacific Ocean during the last 15 years using various combinations of low-frequency, wide-bandwidth transmitters and horizontal and vertical line array receivers, including a 2-dimensional array with a maximum vertical aperture of 1400 m and a horizontal aperture of 3600 m. These measurements were undertaken to further our understanding of the physics of low-frequency, broadband propagation and the effects of environmental variability on signal stability and coherence. In this volume some of the results are presented. In the present paper the central issues these experiments have addressed are briefly summarized.
Ocean acoustic wave propagation and ray method correspondence: Internal wave fine structure
Authors: Hegewisch Katherine C. , Cerruti Nicholas R. , Tomsovic Steven
Published: March 2005

Acoustic wave fields propagating long ranges through the ocean are refracted by the inhomogeneities in the ocean’s sound speed profile. Intuitively, for a given acoustic source frequency, the inhomogeneities become ineffective at refracting the field beyond a certain fine scale determined by the acoustic wavelength. On the other hand, ray methods are sensitive to infinitely fine features. Thus, it is possible to complicate arbitrarily the ray dynamics, and yet have the wave field propagate unchanged. This feature raises doubts about the ray/wave correspondence. Given the importance of various analyses relying on ray methods, a proper model should, at a minimum, exclude all of the fine structure that does not significantly alter the propagated wave field when the correspondence to the ray dynamics is integral. We develop a simple, efficient, smoothing technique to be applied to the inhomogeneities—a low pass filtering performed in the spatial domain—and give a characterization of its necessary extent as a function of acoustic source frequency. We indicate how the smoothing improves the ray/wave correspondence, and show that the so-called “ray chaos” problem remains above a very low frequency (∼15–25 Hz).
Combined representations for frequency and duration in detection templates for expected signals
Authors: Wright Beverly A.
Published: March 2005

When trying to detect a tonal signal in a continuous broadband noise, listeners attend selectively to both the frequency and the duration of the expected signal. However, it is not known whether they monitor separate or combined representations of these two attributes. To investigate this question, a probe-signal method was used to measure the detectability of signals of expected and unexpected durations at two expected frequencies. The four listeners expected only one of two signals to be presented at random: a brief tone at one frequency or a long tone at another frequency. For each signal frequency, the detectability of the signals of unexpected duration decreased to near chance as the difference between the expected and unexpected duration, at that frequency, increased. The frequency specificity of this duration tuning indicates that both the frequency and the duration of an expected stimulus are represented in a single template.
Estimation of total attenuation and scatterer size from backscattered ultrasound waveforms
Authors: Bigelow Timothy A. , Oelze Michael L. , O’Brien William D.
Published: March 2005

Quantitative ultrasound techniques using backscattered echoes have had limited success in vivo due to the frequency-dependent attenuation along the entire propagation path masking the frequency dependence of the backscatter. Herein, total attenuation and scatterer size are estimated simultaneously by an analysis of the in vivo backscattered power spectrum using two approaches. The simulations used to evaluate the two approaches used frequencies between 4 and 11 MHz with an effective scatterer radius of 25 μm. The first approach was based on approximations of the in vivo backscattered power spectrum (i.e., assumed Gaussian function), wherein attenuation and size were estimated by assuming each was a Gaussian transformation performed on Gaussian power spectra. The approach had poor accuracy due to the backscattered power spectra not being sufficiently modeled by a Gaussian function. The second approach estimated attenuation and size by fitting a modified reference spectrum to the in vivo backscattered power spectrum without any assumptions about the shape of the spectrum. The accuracy of the size estimate was better than 20% for signal-to-noise ratio >6 dB, window lengths greater than 4 mm, and attenuation between 0 and 1 dB/cm-MHz. However, the precision quickly degraded with increasing noise, increasing attenuation, and decreasing window length.
Reading and the Reading Class in the Twenty-First Century
Authors: Griswold Wendy , McDonnell Terry , Wright Nathan
Published: March 2005

Sociological research on reading, which formerly focused on literacy, now conceptualizes reading as a social practice. This review examines the current state of knowledge on (a) who reads, i.e., the demographic characteristics of readers; (b) how they read, i.e., reading as a form of social practice; (c) how reading relates to electronic media, especially television and the Internet; and (d) the future of reading. We conclude that a reading class is emerging, restricted in size but disproportionate in influence, and that the Internet is facilitating this development.
Arginine vasopressin reduces intestinal oxygen supply and mucosal tissue oxygen tension
Authors: Knotzer H. , Pajk W. , Maier S. , Ladurner R. , Kleinsasser A. , Wenzel V. , Dünser M. W. , Ulmer H. , Hasibeder W. R.
Published: March 2005

We investigated intestinal oxygen supply and mucosal tissue Po2during administration of increasing dosages of continuously infused arginine vasopressin (AVP) in an autoperfused, innervated jejunal segments in anesthetized pigs. Mucosal tissue Po2was measured by employing two Clark-type surface oxygen electrodes. Oxygen saturation of jejunal microvascular hemoglobin was determined by tissue reflectance spectrophotometry. Microvascular blood flow was assessed by laser-Doppler velocimetry. Systemic hemodynamic variables, mesenteric venous and systemic acid-base and blood gas variables, and lactate measurements were recorded. Measurements were performed at baseline and at 20-min intervals during incremental AVP infusion ( n = 8; 0.007, 0.014, 0.029, 0.057, 0.114, and 0.229 IU·kg−1·h−1, respectively) or infusion of saline ( n = 8). AVP infusion led to a significant ( P < .05), dose-dependent decrease in cardiac index (from 121 ± 31 to 77 ± 27 ml·kg−1·min−1at 0.229 IU·kg−1·h−1) and systemic oxygen delivery (from 14 ± 3 to 9 ± 3 ml·kg−1·min−1at 0.229 IU·kg−1·h−1) concomitant with an increase in systemic oxygen extraction ratio (from 31 ± 4 to 48 ± 10%). AVP decreased microvascular blood flow (from 133 ± 47 to 82 ± 35 perfusion units at 0.114 IU·kg−1·h−1), mucosal tissue Po2(from 26 ± 7 to 7 ± 2 mmHg at 0.229 IU·kg−1·h−1), and microvascular hemoglobin oxygen saturation (from 51 ± 9 to 26 ± 12% at 0.229 IU·kg−1·h−1) without a significant increase in mesenteric venous lactate concentration (2.3 ± 0.8 vs. 3.4 ± 0.7 mmol/l). We conclude that continuously infused AVP decreases intestinal oxygen supply and mucosal tissue Po2due to a reduction in microvascular blood flow and due to the special vascular supply in the jejunal mucosa in a dose-dependent manner in pigs.
Remote arteriolar dilations caused by methacholine: a role for CGRP sensory nerves?
Authors: Thengchaisri Naris , Rivers Richard J.
Published: March 2005

Remote vasodilation caused by arteriolar microapplication of acetylcholine cannot be completely attributed to passive cell-cell communication of a hyperpolarizing signal. The present study was undertaken to ascertain whether a neural component may be involved in the remote response. In the cheek pouch of anesthetized hamsters, methacholine (100 μM) was applied to the arteriole by micropipette for 5 s, and the arteriolar responses were measured at the site of application and at remote locations: 500 and 1,000 μm upstream from the application site. Superfusion with the local anesthetic bupivacaine attenuated a local dilatory response and abolished the conducted dilation response to methacholine. Localized micropipette application of bupivacaine 300 μm from the methacholine application site also attenuated the remote dilation but did not inhibit the local dilation. Blockade of neuromuscular transmission with botulinum neurotoxin A (1 U, 3 days), micropipette application of calcitonin gene-related peptide (CGRP) receptor inhibitor CGRP-(8–37) (10 μM) 300 μm upstream from the methacholine application site, and denervation of the CGRP sensory nerve by 2 days of capsaicin treatment reduced the conducted dilation response to methacholine but did not affect the local dilatory response. Together, these data support involvement of a TTX-insensitive nerve, specifically the CGRP containing nerve, in vascular communication. Understanding the effect of regulation of a novel neural network system on the vascular network may lead to a new insight into regulation of blood flow and intraorgan blood distribution.
Lysophosphatidylcholine increases endothelial permeability: role of PKCα and RhoA cross talk
Authors: Huang Fei , Subbaiah Papasani V. , Holian Oksana , Zhang Jihang , Johnson Arnold , Gertzberg Nancy , Lum Hazel
Published: March 2005

Lysophosphatidylcholine (LPC) is a bioactive proinflammatory lipid that can be generated by pathological activities. We investigated the hypothesis that LPC signals increase in endothelial permeability. Stimulation of human dermal microvascular endothelial cells and bovine pulmonary microvascular endothelial cells with LPC (10–50 μM) induced decreases (within minutes) in transendothelial electrical resistance and increase of endothelial permeability. LPC activated (within 5 min) membrane-associated PKC phosphotransferase activity in the absence of translocation. Affinity-binding analysis indicated that LPC induced increases (also by 5 min) of GTP-bound RhoA, but not Rac1 or Cdc42. By 60 min, both signaling pathways decreased toward baseline. Inhibition of RhoA with C3 transferase inhibited ∼50% of LPC-induced resistance decrease. Pretreatment with PKC inhibitor Gö-6983 (concentrations selective for classic PKC), PMA-induced depletion of PKCα, and transfection of antisense PKCα oligonucleotide each prevented 40–50% of the LPC-induced resistance decrease. Furthermore, these three PKC inhibition strategies inhibited 60–80% of the LPC-induced GTP-bound RhoA. These results show that LPC directly impairs the endothelial barrier function that was dependent, at least in part, on cross talk of PKCα and RhoA signals. The evidence indicates that elevated LPC levels can contribute to the activation of a proinflammatory endothelial phenotype.
CoPub Mapper: mining MEDLINE based on search term co-publication
Authors: Alako Blaise TF , Veldhoven Antoine , van Baal Sjozef , Jelier Rob , Verhoeven Stefan , Rullmann Ton , Polman Jan , Jenster Guido
Published: March 2005

Background

High throughput microarray analyses result in many differentially expressed genes that are potentially responsible for the biological process of interest. In order to identify biological similarities between genes, publications from MEDLINE were identified in which pairs of gene names and combinations of gene name with specific keywords were co-mentioned.

Results

MEDLINE search strings for 15,621 known genes and 3,731 keywords were generated and validated. PubMed IDs were retrieved from MEDLINE and relative probability of co-occurrences of all gene-gene and gene-keyword pairs determined. To assess gene clustering according to literature co-publication, 150 genes consisting of 8 sets with known connections (same pathway, same protein complex, or same cellular localization, etc.) were run through the program. Receiver operator characteristics (ROC) analyses showed that most gene sets were clustered much better than expected by random chance. To test grouping of genes from real microarray data, 221 differentially expressed genes from a microarray experiment were analyzed with CoPub Mapper, which resulted in several relevant clusters of genes with biological process and disease keywords. In addition, all genes versus keywords were hierarchical clustered to reveal a complete grouping of published genes based on co-occurrence.

Conclusion

The CoPub Mapper program allows for quick and versatile querying of co-published genes and keywords and can be successfully used to cluster predefined groups of genes and microarray data.
WEBnm@: a web application for normal mode analyses of proteins
Authors: Hollup Siv Midtun , Salensminde Gisle , Reuter Nathalie
Published: March 2005

Background

Normal mode analysis (NMA) has become the method of choice to investigate the slowest motions in macromolecular systems. NMA is especially useful for large biomolecular assemblies, such as transmembrane channels or virus capsids. NMA relies on the hypothesis that the vibrational normal modes having the lowest frequencies (also named soft modes) describe the largest movements in a protein and are the ones that are functionally relevant.

Results

We developed a web-based server to perform normal modes calculations and different types of analyses. Starting from a structure file provided by the user in the PDB format, the server calculates the normal modes and subsequently offers the user a series of automated calculations; normalized squared atomic displacements, vector field representation and animation of the first six vibrational modes. Each analysis is performed independently from the others and results can be visualized using only a web browser. No additional plug-in or software is required. For users who would like to analyze the results with their favorite software, raw results can also be downloaded. The application is available on http://www.bioinfo.no/tools/normalmodes. We present here the underlying theory, the application architecture and an illustration of its features using a large transmembrane protein as an example.

Conclusion

We built an efficient and modular web application for normal mode analysis of proteins. Non specialists can easily and rapidly evaluate the degree of flexibility of multi-domain protein assemblies and characterize the large amplitude movements of their domains.
Regulation of prokineticin 2 expression by light and the circadian clock
Authors: Cheng Michelle Y , Bittman Eric L , Hattar Samer , Zhou Qun-Yong
Published: March 2005

Background

The suprachiasmatic nucleus (SCN) contains the master circadian clock that regulates daily rhythms of many physiological and behavioural processes in mammals. Previously we have shown that prokineticin 2 (PK2) is a clock-controlled gene that may function as a critical SCN output molecule responsible for circadian locomotor rhythms. As light is the principal zeitgeber that entrains the circadian oscillator, and PK2 expression is responsive to nocturnal light pulses, we further investigated the effects of light on the molecular rhythm of PK2 in the SCN. In particular, we examined how PK2 responds to shifts of light/dark cycles and changes in photoperiod. We also investigated which photoreceptors are responsible for the light-induced PK2 expression in the SCN. To determine whether light requires an intact functional circadian pacemaker to regulate PK2, we examined PK2 expression in cryptochrome1,2-deficient (Cry1-/-Cry2-/-) mice that lack functional circadian clock under normal light/dark cycles and constant darkness.

Results

Upon abrupt shifts of the light/dark cycle, PK2 expression exhibits transients in response to phase advances but rapidly entrains to phase delays. Photoperiod studies indicate that PK2 responds differentially to changes in light period. Although the phase of PK2 expression expands as the light period increases, decreasing light period does not further condense the phase of PK2 expression. Genetic knockout studies revealed that functional melanopsin and rod-cone photoreceptive systems are required for the light-inducibility of PK2. In Cry1-/-Cry2-/- mice that lack a functional circadian clock, a low amplitude PK2 rhythm is detected under light/dark conditions, but not in constant darkness. This suggests that light can directly regulate PK2 expression in the SCN.

Conclusion

These data demonstrate that the molecular rhythm of PK2 in the SCN is regulated by both the circadian clock and light. PK2 is predominantly controlled by the endogenous circadian clock, while light plays a modulatory role. The Cry1-/-Cry2-/- mice studies reveal a light-driven PK2 rhythm, indicating that light can induce PK2 expression independent of the circadian oscillator. The light inducibility of PK2 suggests that in addition to its role in clock-driven rhythms of locomotor behaviour, PK2 may also participate in the photic entrainment of circadian locomotor rhythms.
Activity of glucose oxidase functionalized onto magnetic nanoparticles
Authors: Kouassi Gilles K , Irudayaraj Joseph , McCarty Gregory
Published: March 2005

Background

Magnetic nanoparticles have been significantly used for coupling with biomolecules, due to their unique properties.

Methods

Magnetic nanoparticles were synthesized by thermal co-precipitation of ferric and ferrous chloride using two different base solutions. Glucose oxidase was bound to the particles by direct attachment via carbodiimide activation or by thiophene acetylation of magnetic nanoparticles. Transmission electron microscopy was used to characterize the size and structure of the particles while the binding of glucose oxidase to the particles was confirmed using Fourier transform infrared spectroscopy.

Results

The direct binding of glucose oxidase via carbodiimide activity was found to be more effective, resulting in bound enzyme efficiencies between 94–100% while thiophene acetylation was 66–72% efficient. Kinetic and stability studies showed that the enzyme activity was more preserved upon binding onto the nanoparticles when subjected to thermal and various pH conditions. The overall activity of glucose oxidase was improved when bound to magnetic nanoparticles

Conclusion

Binding of enzyme onto magnetic nanoparticles via carbodiimide activation is a very efficient method for developing bioconjugates for biological applications
Inflammatory cytokine levels correlate with amyloid load in transgenic mouse models of Alzheimer's disease
Authors: Patel Nikunj S , Paris Daniel , Mathura Venkatarajan , Quadros Amita N , Crawford Fiona C , Mullan Michael J
Published: March 2005

Background

Inflammation is believed to play an important role in the pathology of Alzheimer's disease (AD) and cytokine production is a key pathologic event in the progression of inflammatory cascades. The current study characterizes the cytokine expression profile in the brain of two transgenic mouse models of AD (TgAPPsw and PS1/APPsw) and explores the correlations between cytokine production and the level of soluble and insoluble forms of Aβ.

Methods

Organotypic brain slice cultures from 15-month-old mice (TgAPPsw, PS1/APPsw and control littermates) were established and multiple cytokine levels were analyzed using the Bio-plex multiple cytokine assay system. Soluble and insoluble forms of Aβ were quantified and Aβ-cytokine relationships were analyzed.

Results

Compared to control littermates, transgenic mice showed a significant increase in the following pro-inflammatory cytokines: TNF-α, IL-6, IL-12p40, IL-1β, IL-1α and GM-CSF. TNF-α, IL-6, IL-1α and GM-CSF showed a sequential increase from control to TgAPPsw to PS1/APPsw suggesting that the amplitude of this cytokine response is dependent on brain Aβ levels, since PS1/APPsw mouse brains accumulate more Aβ than TgAPPsw mouse brains. Quantification of Aβ levels in the same slices showed a wide range of Aβ soluble:insoluble ratio values across TgAPPsw and PS1/APPsw brain slices. Aβ-cytokine correlations revealed significant relationships between Aβ1–40, 1–42 (both soluble and insoluble) and all the above cytokines that changed in the brain slices.

Conclusion

Our data confirm that the brains of transgenic APPsw and PS1/APPsw mice are under an active inflammatory stress, and that the levels of particular cytokines may be directly related to the amount of soluble and insoluble Aβ present in the brain suggesting that pathological accumulation of Aβ is a key driver of the neuroinflammatory response.
Enthalpy relaxation of bovine serum albumin and implications for its storage in the glassy state
Authors: Farahnaky Asgar , Badii Fojan , Farhat Imad A. , Mitchell John R. , Hill Sandra E.
Published: March 2005

Two endothermic peaks could be observed for five commercial samples of bovine serum albumin (BSA). The smaller peak observed by differential scanning calorimetry (DSC) corresponded to enthalpy relaxation. This peak was followed on storage of BSA, in its glassy state, after it had been heated above its denaturation temperature. Enthalpy and peak temperature increased with duration of storage. On storage for one week at 60°C, a sample at 8.3% moisture showed a peak at 100°C with an energy value of approximately 2 J per g protein. BSA samples were heated within the DSC sufficiently to eliminate the lower enthalpy peak but without altering the denaturation enthotherm. The amount of physical aging shown by these BSA samples was similar to that of the heat‐denatured samples. It was concluded that the heating endotherms of dry BSA reflect both the storage and thermal history of the sample. Possible implications of the enthalpy relaxation of BSA on the behavior of this important protein are considered. © 2005 Wiley Periodicals, Inc. Biopolymers 78: 69–77, 2005