bluuebunny/crossref_metadata_2025 huggingface dataset:
Profile analysis: Critical bands and duration
Authors: Green David M. , Mason Christine R. , Kidd Gerald
Published: October 2005

The detection of an increment in the intensity of the central component of a multi-component complex was measured as a function of the frequency spacing of the components and the duration of the presentation. The overall intensity of the complex was randomly varied on each presentation of the stimulus. Curiously, the increment becomes easier to hear as the range and density of the surrounding complex is increased. This increase in range and density is also effective in improving the detectability of the increment when there is no random variation in intensity, i.e., a conventional Weber fraction experiment. This is unlike the results obtained in many other critical-band experiments where energy remote from the signal frequency has little or no effect. Measurement of the effects of signal duration showed that when presentations were shorter than about 100 msec a greater increment in intensity was required than for longer durations. These results with duration are similar to those obtained in other intensity-discrimination tasks.
Calculation of the second term in the geometrical acoustic expansion
Authors: Stickler D. C. , Tavantzis J. , Ammicht E.
Published: October 2005

One method to estimate the validity of the leading term in the geometrical acoustics expansion is to calculate the second term in the expansion. This second term plays an essential role in the construction of the second term in Ludwig’s uniform smooth caustic ansatz and in the construction of the progressing wave smooth caustic ansatz. Therefore, the determination of this term is important in the assessment of each of these expansions. Expressions for this second term are derived valid for arbitrary index profiles near the source point and near a smooth caustic. Numerical examples are presented for the n2-linear profile. These results show that near the source the second term is not singular, but near the caustic it is more singular than the leading order term.
An improvement in the range resolution of ultrasonic pulse echo systems by deconvolution
Authors: Carpenter R. N. , Stepanishen P. R.
Published: October 2005

Ultrasonic pulse echo systems are often limited in range resolution by the bandwidth of the piezoelectric transducer. Significant improvements in the range resolution of such systems can be obtained by minimizing the effects of the transducer’s dynamic response on the overall pulse echo process. An approach to minimize the effects of the transducer is developed from linear system and impulse response techniques. In essence, the pulse echo voltage of interest is deconvolved with a pulse echo reference voltage which is obtained from an air/water interface in the nearfield of the transducer. A computer study of the pulse echo process and the deconvolution process is presented to illustrate the nature of the improvement in range resolution for several cases of interest. Finally, experimental results are presented to illustrate the improvement using commercially available transducers.
Development and application of multiple input models for structural noise source identification of forge hammers. Part I: Development
Authors: Trethewey Martin W. , Evensen Harold A.
Published: October 2005

The application of multiple input models to analyze structurally generated noise from a forge hammer is discussed. Part I of this article is intended to present the rationale for application and analysis of multiple input models for noise source identification. The development of the empirical models is reviewed and investigated to show how the terms in the model can be interpreted to mathematically simulate the selective wrapping approach to source identification. The interaction of the structural excitation forces and radiated structural noise is examined for a four-piece forge hammer and provides an indication of the characteristic measurements needed to develop the multiple input model that is representative of the hammer’s sound radiation. The transducer requirements for application to forge hammers are examined through experiments performed on a laboratory test structure and a forge hammer column. The results indicate that a single, well-placed transducer may be sufficient to characterize the sound radiation from a monolithic element. Part II of this article analyzes the application of the techniques to a Chambersburg ♯8 die forger under production conditions. The experimental results indicate that the ram is the dominant source of sound energy, the columns are secondary sources, and the yoke and anvil are minor sources when detected through a microphone at the operator’s position.
Linearized travel time, intensity, and waveform inversions in the ocean sound channel—A comparison
Authors: Brown Michael G.
Published: October 2005

Linearized inversion schemes involving waveform (total record), intensity (dephased total record), and travel times (intensity peaks) are used on synthetically generated arrival patterns to solve for the sound speed structure in the upper km of a range-independent ocean model. In all three cases inversions are carried out for a variety of source center frequencies and bandwidths. The results are compared; conditions under which each inversion method performs poorly and well are outlined. The nature of the linearization approximation is discussed for each of the three types of inversion scheme as well as the methods used to solve the general linearized system.
Nearfield of a large acoustic transducer. Part IV: Second harmonic and sum frequency radiation
Authors: Berntsen Jarle , Tjo/tta Jacqueline Naze , Tjo/tta Sigve
Published: October 2005

The theory presented in two previous papers [J. Acoust. Soc. Am. 74, 1013–1020 (1983) and J. Acoust. Soc. Am. 75, 769–779 (1984)] is generalized to the second harmonic and sum frequency components in the acoustic beam from a moderate amplitude parametric radiator. The theory also applies to the second harmonic component in the acoustic field from a moderate amplitude monochromatic transducer. Asymptotic formulas are presented, showing the development of the second harmonic and sum frequency sound from the source (transducer) into the farfield. Numerical results for the axisymmetric case are given. The results are compared with earlier theories and observations.
Bubble size measurements using the nonlinear mixing of two frequencies
Authors: Newhouse V. L. , Shankar P. Mohana
Published: October 2005

A double frequency method of measuring bubble size which has better spatial resolution than previous techniques, is described. Bubbles are insonified simultaneously by a swept, relatively low, ‘‘pumping’’ frequency near their resonance and a high ‘‘imaging’’ frequency. Theoretical expressions are derived for the sound scattered by a bubble under the influence of these two frequencies. Existence of sharp resonance behavior in the scattered sound at the sum frequency is shown both theoretically and experimentally.
Speech perception by infants: Categorization based on nasal consonant place of articulation
Authors: Hillenbrand James
Published: October 2005

This study examined the ability of six-month-old infants to recognize the perceptual similarity of syllables sharing a phonetic segment when variations were introduced in phonetic environment and talker. Infants in a ‘‘phonetic’’ group were visually reinforced for head turns when a change occurred from a background category of labial nasals to a comparison category of alveolar nasals. The infants were initially trained on a [ma]–[na] contrast produced by a male talker. Novel tokens differing in vowel environment and talker were introduced over several stages of increasing complexity. In the most complex stage infants were required to make a head turn when a change occurred from [ma,mi,mu] to [na,ni,nu], with the tokens in each category produced by both male and female talkers. A ‘‘nonphonetic’’ control group was tested using the same pool of stimuli as the phonetic condition. The only difference was that the stimuli in the background and comparison categories were chosen in such a way that the sounds could not be organized by acoustic or phonetic characteristics. Infants in the phonetic group transferred training to novel tokens produced by different talkers and in different vowel contexts. However, infants in the nonphonetic control group had difficulty learning the phonetically unrelated tokens that were introduced as the experiment progressed. These findings suggest that infants recognize the similarity of nasal consonants sharing place of articulation independent of variation in talker and vowel context.
Some observations on tone color in the recurved flute
Authors: Laszewski R. M. , Murray A. D.
Published: October 2005

Inferences about possible tone-color differences between the normal and the recurved flute are made based on radiated power calculations similar to those of Coltman. The results of a blind listening test of these differences by a group of musicians are described.
Diffraction of elastic waves by a sub-surface crack (in-plane motion)
Authors: van der Hijden J. H. M. T. , Neerhoff F. L.
Published: October 2005

A rigorous theory of the diffraction of time-harmonic elastic waves by an arbitrarily oriented, cylindrical, stress-free crack of finite width embedded in a semi-infinite elastic medium is presented. The incident wave is taken to be either a P wave, an SV wave, or a Rayleigh wave. The resulting boundary-value problems for the unknown jump in the particle displacement across the crack are solved by employing the integral-equation method in combination with the Galerkin method. Numerical results are presented in the form of scattering cross sections, normalized power scattering characteristics, dynamic stress intensity factors, and Rayleigh wave transmission and reflection coefficients, for a range of geometrical parameters.
The cruciform dynamic vibration absorber
Authors: Snowdon J. C. , Wolfe A. A. , Kerlin R. L.
Published: October 2005

The cruciform dynamic absorber comprises two free–free beams that are mass loaded at their free ends and that are joined centrally at right angles at a point at which they are attached to the vibrating item or structure of concern. Both a lumped simple system and distributed mechanical systems such as beams and clamped circular plates are considered. The damping of the absorber beams and of the lumped and distributed mechanical systems is assumed throughout to be of the solid type. The branches (arms) of the cruciform dynamic absorber are generally tuned to the fundamental and second or third resonances of the distributed mechanical systems considered. Sometimes, one branch is tuned to the fundamental resonance of the distributed mechanical system concerned while the other branch, with essentially zero damping, is tuned off resonance, for example, to the frequency of a troublesome machinery discrete, thereby generating a pronounced trough in the transmissibility curve with a compensating transmissibility peak at a slightly higher frequency that is not necessarily of predominant magnitude.
Hybrid time-delay/phase-shift digital beamforming for uniform collinear arrays
Authors: Gabel Robert A. , Kurth Richard R.
Published: October 2005

Digital phase-shift beamforming of narrow-band signals from uniform collinear hydrophone arrays may be accomplished by computationally efficient discrete Fourier transform (DFT) algorithms. However, phase-shift beamforming is a valid approximation to delay-and-sum steering only over a restricted bandwidth limited by array aperture and steering angle. A multiple-beam digital beamforming technique is described which is a hybrid of phase-shift and time-delay operations designed for bandwidths in excess of the phase-shift limit. The beamformer employs fast DFTs for phase-shifting, organized according to a particular decomposition of the array into subarrays, plus a limited amount of delay steering by interpolation. The result is a substantial reduction in the number of digital arithmetic operations compared with the alternative of delay-and-sum steering by interpolation. The design principles of the hybrid beamformer are described and an example presented to illustrate its computational advantages.
Model studies of barrier performance in the presence of ground surfaces. Part II—Different shapes
Authors: Hutchins D. A. , Jones H. W. , Russell L. T.
Published: October 2005

Modeling experiments are reported which have investigated the frequency dependence of barrier insertion loss for various noise barrier designs. The effect of ground surfaces has been studied, treating both grass-covered ground and asphalt. Results show that interference effects are an important feature of observed behavior. Use is made of this knowledge in the design and testing of new barrier designs, which deliberately introduce a beneficial destructive interference phenomenon to increase insertion losses over well-defined ranges of frequency.
Anti-Realism in Government
Authors: Oreskes Naomi
Published: October 2005

The Republican War on Science
.
By Chris Mooney
. Basic Books, New York, 2005. 338 pp. $24.95, C$32.95. ISBN 0-465-04675-4.

The author discusses the manipulation, distortion, and suppression of scientific findings in an effort to advance a partisan agenda and explores the ideological roots of this assault on science
Connected to Death: The (Unexpurgated) Mitochondrial Pathway of Apoptosis
Authors: Spierings Diana , McStay Gavin , Saleh Maya , Bender Cheryl , Chipuk Jerry , Maurer Uli , Green Douglas R.
Published: October 2005

The mitochondrial pathway of apoptosis in vertebrates is dependent on the process of mitochondrial outer membrane permeabilization (MOMP), which leads to the release of proteins from the mitochondrial intermembrane space into the cytosol. “Upstairs” of this event are the Bcl-2 family proteins that regulate and mediate MOMP; “downstairs” is the activation of caspases that orchestrate the dismantling of the cell. In the Connections Map database at
Science
's Signal Transduction Knowledge Environment (STKE), the pathways that define the mitochondrial pathway of apotosis are illustrated, with the bulk of control occurring “upstairs” of MOMP.
After the Earth Shook
Authors: Hough Susan E.
Published: October 2005

A Crack in the Edge of the World
. America and the Great California Earthquake of 1906.
By Simon Winchester
. HarperCollins, New York, 2005. 478 pp. $27.95, C$37.95. ISBN 0-06-057199-3.

A Crack in the Edge of the World
. The Great American Earthquake of 1906. Viking, London, 2005. £16.99. ISBN 0-670-91487-8.

A blend of science and history, the author's account of the devastating 1906 San Francisco earthquake and its aftermath frequently wanders into intriguing digressions.
G Proteins Go Green: A Plant G Protein Signaling FAQ Sheet
Authors: Assmann Sarah M.
Published: October 2005

Plants, like animals, use signal transduction pathways based on heterotrimeric guanine nucleotide–binding proteins (G proteins) to regulate many aspects of development and cell signaling. Some components of G protein signaling are highly conserved between plants and animals and some are not. This Viewpoint compares key aspects of G protein signal transduction in plants and animals and describes the current knowledge of this system in plants, the questions that still await exploration, and the value of research on plant G proteins to scientists who do not study plants. Pathways in
Science
's Signal Transduction Knowledge Environment Connections Maps database provide details about the emerging roles of G proteins in several cellular processes of plants.
Evaluation of Serum Antibody Responses against the Rotavirus Nonstructural Protein NSP4 in Children after Rhesus Rotavirus Tetravalent Vaccination or Natural Infection
Authors: Vizzi Esmeralda , Calviño Eva , González Rosabel , Pérez-Schael Irene , Ciarlet Max , Kang Gagandeep , Estes Mary K. , Liprandi Ferdinando , Ludert Juan E.
Published: October 2005

The immune response elicited by the rotavirus nonstructural protein NSP4 and its potential role in protection against rotavirus disease are not well understood. We investigated the serological response to NSP4 and its correlation with disease protection in sera from 110 children suffering acute diarrhea, associated or not with rotavirus, and from 26 children who were recipients of the rhesus rotavirus tetravalent (RRV-TV) vaccine. We used, as antigens in an enzyme-linked immunosorbent assay (ELISA), affinity-purified recombinant NSP4 (residues 85 to 175) from strains SA11, Wa, and RRV (genotypes A, B, and C, respectively) fused to glutathione
S
-transferase. Seroconversion to NSP4 was observed in 54% (42/78) of the children who suffered from natural rotavirus infection and in 8% (2/26) of the RRV-TV vaccine recipients. Our findings indicate that NSP4 evokes significantly (
P
< 0.05) higher seroconversion rates after natural infection than after RRV-TV vaccination. The serum antibody levels to NSP4 were modest (titers of ≤200) in most of the infected and vaccinated children. A heterotypic NSP4 response was detected in 48% of the naturally rotavirus-infected children with a detectable response to NSP4. Following natural infection or RRV-TV vaccination, NSP4 was significantly less immunogenic than the VP6 protein when these responses were independently measured by ELISA. A significant (
P
< 0.05) proportion of children who did not develop diarrhea associated with rotavirus had antibodies to NSP4 in acute-phase serum, suggesting that serum antibodies against NSP4 might correlate with protection from rotavirus diarrhea. In addition, previous exposures to rotavirus did not affect the NSP4 seroconversion rate.
Serologic Cross-Reactivity between
Anaplasma marginale
and
Anaplasma phagocytophilum
Authors: Dreher U. M. , de la Fuente J. , Hofmann-Lehmann R. , Meli M. L. , Pusterla N. , Kocan K. M. , Woldehiwet Z. , Braun U. , Regula G. , Staerk K. D. C. , Lutz H.
Published: October 2005

In the context of a serosurvey conducted on the
Anaplasma marginale
prevalence in Swiss cattle, we suspected that a serological cross-reactivity between
A. marginale
and
A. phagocytophilum
might exist. In the present study we demonstrate that cattle, sheep and horses experimentally infected with
A. phagocytophilum
not only develop antibodies to
A. phagocytophilum
(detected by immunofluorescent-antibody assay) but also to
A. marginale
(detected by a competitive enzyme-linked immunosorbent assay). Conversely, calves experimentally infected with
A. marginale
also developed antibodies to
A. phagocytophilum
using the same serological tests. The identity of 63% determined in silico within a 209-amino-acid sequence of major surface protein 5 of an isolate of
A. marginale
and one of
A. phagocytophilum
supported the observed immunological cross-reactivity. These observations have important consequences for the serotesting of both,
A. marginale
and
A. phagocytophilum
infection of several animal species. In view of these new findings, tests that have been considered specific for either infection must be interpreted carefully.
Priming of Immunological Memory by Pneumococcal Conjugate Vaccine in Children Unresponsive to 23-Valent Polysaccharide Pneumococcal Vaccine
Authors: Rose Markus A. , Schubert Ralf , Strnad Nicola , Zielen Stefan
Published: October 2005

Pneumococcal polysaccharide vaccine (PPV) is of limited immunogenicity in infants and immunocompromised patients. Our prospective randomized controlled trial investigated whether priming with pneumococcal conjugate vaccine (PCV) induced specific immunological memory in previously nonresponders to PPV. Of a total of 33 children (2 to 18 years) with polysaccharide-specific immunodeficiency (PSI), group A (
n
= 16) received two doses of 7-valent PCV in a 4- to 6-week interval, and a booster dose of 23-valent PPV after one year. Group B (
n
= 17) received two doses of PPV in a 1-year interval exclusively. Specific antibody concentrations for serotypes 4, 5, 6B, 9V, 14, 18C, 19F, and 23F were determined (enzyme-linked immunosorbent assay) before and at 7 and 28 days after administration of the PPV booster and compared to an opsonophagocytosis assay. Of group A, 64 to 100% had antibody concentrations of ≥1 μg/ml on day 28 after the booster versus 25 to 94% of group B. Group A had significantly higher antibody concentrations for all PCV-containing serotypes already on day 7, indicating early memory response. Antibody concentrations were in accordance with functional opsonic activity, although opsonic titers varied among individuals. Pneumococcal vaccination was well tolerated. The incidence of airway infections was reduced after priming with PCV (10/year for group A versus 15/year for group B). Following a PPV booster, even patients primarily not responding to PPV showed a rapid and more pronounced memory response after priming with PCV.
Immunogenicity of Meningococcal ACYW135 Polysaccharide Vaccine in Saudi Children 5 to 9 Years of Age
Authors: Khalil M. , Al-Mazrou Y. , Balmer P. , Bramwell J. , Andrews N. , Borrow R.
Published: October 2005

Meningococcal tetravalent polysaccharide vaccines were observed to be immunogenic in Saudi children 5 to 9 years of age, with >90% having serum bactericidal antibody titers of ≥8 for serogroups A, Y, and W135; for serogroup C, 77% were putatively protected after vaccination.
Correlation between clinical diagnosis and arthroscopic findings of the shoulder
Authors: Malhi A M , Khan R
Published: October 2005

Objective

To assess the accuracy of clinical examination by non-specialist orthopaedic surgeons of patients presenting to a diagnostic and treatment centre (DTC) for arthroscopic shoulder surgery.

Methods

A retrospective review of notes of 130 consecutive shoulder arthroscopies performed at a DTC over a 10 month period. Preoperative clinical diagnosis was compared with operative arthroscopic findings. Additional information from preoperative imaging was compared with clinical examination and arthroscopic findings. Preoperative clinical examinations and consent were undertaken by clinical fellows, (SpR level) and non-upper limb consultant orthopaedic surgeons. Consultants specialising in upper limb surgery performed the operations.

Results

Six main groups were identified on the basis of clinical examination: impingement 76 cases (58%), instability 22 cases (17%), frozen shoulder 11 cases (8%), rotator cuff tear four cases (3%), non-specific pain eight cases (6%), and normal clinical examination nine cases (7%). Impingement and instability diagnosed clinically strongly correlated with the arthroscopic findings. Clinical diagnosis of frozen shoulder and rotator cuff tears had a weaker correlation with the arthroscopic findings. Of the nine cases of normal clinical examination, abnormality was found at arthroscopy in all cases.

Conclusion

There have been very few studies comparing clinical examination of the shoulder with arthroscopic findings. This study emphasises the importance of good clinical examination skills in diagnosing common shoulder abnormalities. The addition of imaging, particularly ultrasound and magnetic resonance imaging further increases the likelihood of an accurate diagnosis. Shoulder examination should be taught with as much emphasis at both undergraduate and postgraduate level as other orthopaedic clinical examinations.
Change of nitric oxide in experimental colitis and its inhibition by melatonin in vivo and in vitro
Authors: Mei Q , Xu J-M , Xiang L , Hu Y-M , Hu X-P , Xu Z-W
Published: October 2005

Aim

To investigate the change of nitric oxide (NO) in rat colitis and its inhibition by melatonin in vivo and in vitro.

Methods

In vivo, rat colitis was established intracolonically with trinitrobenzenesulphonic acid (TNBS) and ethanol. The animals were randomised into five groups: control group, model group, melatonin group (2.5, 5.0, 10.0 mg/kg), and treated intracolonically with saline, saline and melatonin respectively (once a day, from day 7 after colitis was established to day 28). After the end of the experiment, the mucosal damage index (CMDI) and histology score (HS) were evaluated and the level of myeloperoxidase (MPO) and malondiadehyde (MDA) and NO in the colon tissue were measured. In vitro, the co-culture model of the inflamed colon mucosa (from the colitis) with lipopolysaccharide (LPS), and the colonocytes oxidative injury model by hydroxyl radical, were designed respectively to elucidate the inhibition of NO by melatonin.

Results

After treated with TNBS/ethanol, the extent of CMDI and HS, the levels of MPO, MDA, and NO in the model group, were higher than that in the control group; melatonin ameliorated these parameters effectively. The stimulation of LPS increased the level of NO and MPO and MDA in the co-culture model of inflamed colon mucosa, and melatonin significantly reduced the level of MPO, MDA, and NO. In the coloncyte oxidative injury model by hydroxyl radical, the contents of LDH, MDA, and NO were increased; melatonin reversed this oxidative injury considerably.

Conclusion

This study showed that TNBS/ethanol induced colitis was pharmacologically controlled by melatonin in vivo and in vitro.
Non-invasive ventilation in acute cardiogenic pulmonary oedema
Authors: Agarwal R , Aggarwal A N , Gupta D , Jindal S K
Published: October 2005

Non-invasive ventilation (NIV) is the delivery of assisted mechanical ventilation to the lungs, without the use of an invasive endotracheal airway. NIV has revolutionised the management of patients with various forms of respiratory failure. It has decreased the need for invasive mechanical ventilation and its attendant complications. Cardiogenic pulmonary oedema (CPO) is a common medical emergency, and NIV has been shown to improve both physiological and clinical outcomes. From the data presented herein, it is clear that there is sufficiently high level evidence to favour the use of continuous positive airway pressure (CPAP), and that the use of CPAP in patients with CPO decreases intubation rate and improves survival (number needed to treat seven and eight respectively). However, there is insufficient evidence to recommend the use of bilevel positive airway pressure (BiPAP), probably the exception being patients with hypercapnic CPO. More trials are required to conclusively define the role of BiPAP in CPO.
COUPLED QUINTESSENCE IN A POWER-LAW CASE AND THE COSMIC COINCIDENCE PROBLEM
Authors: ZHANG XIN
Published: October 2005

The problem of the cosmic coincidence is a longstanding puzzle. This conundrum may be solved by introducing a coupling between the two dark sectors. In this letter, we study a coupled quintessence scenario in which the scalar field evolves in a power law potential and the mass of dark matter particles depends on a power law function of ϕ. It is shown that this scenario has a stable attractor solution and can thus provide a natural solution to the cosmic coincidence problem.
Further study on the role of HSP70 on Ca2+ homeostasis in rat ventricular myocytes subjected to simulated ischemia
Authors: Liu Jing , Kam Kenneth W. L. , Borchert Gudrun H. , Kravtsov Gennadi M. , Ballard Heather J. , Wong Tak Ming
Published: October 2005

We hypothesized that activation of heat shock protein 70 (HSP70) by preconditioning, which is known to confer delayed cardioprotection, attenuates the impaired handling of Ca2+ at multiple sites. To test the hypothesis, we determined how the ryanodine receptor (RyR), sarco(endo)plasmic reticulum Ca2+-ATPase (SERCA), and Na+/Ca2+ exchanger (NCX) handled Ca2+ in rat ventricular myocytes preconditioned with a κ-opioid receptor agonist, U50488H (UP), followed by blockade of HSP70 with a selective antisense oligonucleotide and subsequently subjected to simulated ischemia. We determined the following: 1) the Ca2+ transients induced by electrical stimulation and caffeine, which provide the overall picture of Ca2+ homeostasis; 2) expression of RyR, SERCA, and NCX; and 3) Ca2+ fluxes via NCX by the use of 45Ca2+ in the rat ventricular myocyte. We found that UP increased the activity of RyR, SERCA, and NCX and the expression of RyR and SERCA. These effects led to increases in the release of Ca2+ from the sarcoplasmic reticulum via RyR and in the removal of Ca2+ from the cytoplasm by reuptake of Ca2+ to the SR via SERCA and by extrusion of Ca2+ out of the cell via NCX. UP also reduced mitochondrial Ca2+ accumulation. All of the effects of UP were either abolished or significantly attenuated by blockade of HSP70 synthesis with a selective antisense oligonucleotide. The results are evidence that activation of HSP70 by preconditioning improves the ischemia-impaired Ca2+ homeostasis at multiple sites in the heart, which may be responsible, at least partly, for attenuated Ca2+ overload, improved recovery in contractile function, and cardioprotection.
Heightened epithelial Na+ channel-mediated Na+ absorption in a murine polycystic kidney disease model epithelium lacking apical monocilia
Authors: Olteanu Dragos , Yoder Bradley K. , Liu Wen , Croyle Mandy J. , Welty Elisabeth A. , Rosborough Kelley , Wyss J. Michael , Bell P. Darwin , Guay-Woodford Lisa M. , Bevensee Mark O. , Satlin Lisa M. , Schwiebert Erik M.
Published: October 2005

The Tg737° rpk autosomal recessive polycystic kidney disease (ARPKD) mouse carries a hypomorphic mutation in the Tg737 gene. Because of the absence of its protein product Polaris, the nonmotile primary monocilium central to the luminal membrane of ductal epithelia, such as the cortical collecting duct (CCD) principal cell (PC), is malformed. Although the functions of the renal monocilium remain elusive, primary monocilia or flagella on neurons act as sensory organelles. Thus we hypothesized that the PC monocilium functions as a cellular sensor. To test this hypothesis, we assessed the contribution of Polaris and cilium structure and function to renal epithelial ion transport electrophysiology. Properties of Tg737° rpk mutant CCD PC clones were compared with clones genetically rescued with wild-type Tg737 cDNA. All cells were grown as polarized cell monolayers with similarly high transepithelial resistance on permeable filter supports. Three- to fourfold elevated transepithelial voltage ( Vte) and short-circuit current ( Isc) were measured in mutant orpk monolayers vs. rescued controls. Pharmacological and cell biological examination of this enhanced electrical end point in mutant monolayers revealed that epithelial Na+ channels (ENaCs) were upregulated. Amiloride, ENaC-selective amiloride analogs (benzamil and phenamil), and protease inhibitors (aprotinin and leupeptin) attenuated heightened Vte and Isc. Higher concentrations of additional amiloride analogs (ethylisopropylamiloride and dimethylamiloride) also revealed inhibition of Vte. Cell culture requirements and manipulations were also consistent with heightened ENaC expression and function. Together, these data suggest that ENaC expression and/or function are upregulated in the luminal membrane of mutant, cilium-deficient orpk CCD PC monolayers vs. cilium-competent controls. When the genetic lesion causes loss or malformation of the monocilium, ENaC-driven Na+ hyperabsorption may explain the rapid emergence of severe hypertension in a majority of patients with ARPKD.
Hyperacidity of secreted fluid from submucosal glands in early cystic fibrosis
Authors: Song Yuanlin , Salinas Danieli , Nielson Dennis W. , Verkman A. S.
Published: October 2005

Prior studies have shown that fluid secretions from airway submucosal glands in cystic fibrosis (CF) are reduced and hyperviscous, possibly contributing to the pathogenesis of CF airway disease. Because the CF transmembrane conductance regulator (CFTR) protein can transport both chloride and bicarbonate, we investigated whether gland fluid pH is abnormal in early CF, using nasal biopsies from pediatric subjects having minimal CF lung disease. Gland fluid pH, measured in freshly secreted droplets under oil stained with BCECF-dextran, was 6.57 ± 0.09 (mean ± SE) in biopsies from six CF subjects, significantly lower than 7.18 ± 0.06 in eight non-CF biopsies ( P < 0.01). To rule out the possibility that the apparent gland fluid hyperacidity in CF results from modification of fluid pH by the airway surface, a microcannulation method was used to measure pH in fluid exiting gland orifices. In pig trachea and human bronchi, gland fluid pH was reduced by up to 0.45 units by CFTR inhibitors, but was not affected by amiloride. Acid base transport in the surface epithelium of pig trachea was studied from pH changes in 300-nl fluid droplets deposited onto the oil-covered airway surface. The droplets had specified ionic composition/pH and/or contained transporter activators/inhibitors. We found evidence for CFTR-dependent bicarbonate transport by the tracheal surface epithelium as well as ATP/histamine-stimulated proton secretion, but not for sodium/proton or chloride/bicarbonate exchange. These results provide evidence for intrinsic hyperacidity in CF gland fluid secretions, which may contribute to CF airway pathology.
Mineralocorticoids decrease the activity of the apical small-conductance K channel in the cortical collecting duct
Authors: Wei Yuan , Babilonia Elisa , Sterling Hyacinth , Jin Yan , Wang Wen-Hui
Published: October 2005

We used the patch-clamp technique to examine the effect of DOCA treatment (2 mg/kg) on the apical small-conductance K (SK) channels, epithelial Na channels (ENaC), and the basolateral 18-pS K channels in the cortical collecting duct (CCD). Treatment of rats with DOCA for 6 days significantly decreased the plasma K from 3.8 to 3.1 meq and reduced the activity of the SK channel, defined as NPo, from 1.3 in the CCD of control rats to 0.6. In contrast, DOCA treatment significantly increased ENaC activity from 0.01 to 0.53 and the basolateral 18-pS K channel activity from 0.67 to 1.63. Moreover, Western blot analysis revealed that DOCA treatment significantly increased the expression of the nonreceptor type of protein tyrosine kinase (PTK), cSrc, and the tyrosine phosphorylation of ROMK in the renal cortex and outer medulla. The possibility that decreases in apical SK channel activity induced by DOCA treatment were the result of stimulation of PTK activity was further supported by experiments in which inhibition of PTK with herbimycin A significantly increased NPo from 0.6 to 2.1 in the CCD from rats receiving DOCA. Also, when rats were fed a high-K (10%) diet, DOCA treatment did not increase the expression of c-Src and decrease the activity of the SK channel in the CCD. We conclude that DOCA treatment decreased the apical SK channel activity in rats on a normal-K diet and that an increase in PTK expression may be responsible for decreased channel activity in the CCD from DOCA-treated rats.
Expression and functions of annexins in the kidney
Authors: Markoff Arseni , Gerke Volker
Published: October 2005

This review article summarizes current knowledge about the locations and possible functions of annexin family members in the kidney. Beginning with an introduction on common structural and biochemical features as well as general functional characteristics of annexins, the paper focuses on individual members with documented and/or proposed physiological relevance for renal development, structure, and functions. Three main aspects of annexin function in kidney epithelia emerge from the available experimental data. First, annexins are required for membrane organization and membrane transport events required for the establishment/maintenance of epithelial polarity. Second, there is accumulating evidence of an association of annexins with ion channels, as membrane-guiding auxiliary proteins or modulators of channel activity. Last but not least, some annexins seem to work as extracellular autocrine modulators of receptor function under different physiological conditions.
Mechanics of Slope Walking in the Cat: Quantification of Muscle Load, Length Change, and Ankle Extensor EMG Patterns
Authors: Gregor Robert J. , Smith D. Webb , Prilutsky Boris I.
Published: October 2005

Unexpected changes in flexor–extensor muscle activation synergies during slope walking in the cat have been explained previously by 1) a reorganization of circuitry in the central pattern generator or 2) altered muscle and cutaneous afferent inputs to motoneurons that modulate their activity. The aim of this study was to quantify muscle length changes, muscle loads, and ground reaction forces during downslope, level, and upslope walking in the cat. These mechanical variables are related to feedback from muscle length and force, and paw pad cutaneous afferents, and differences in these variables between the slope walking conditions could provide additional insight into possible mechanisms of the muscle control. Kinematics, ground reaction forces, and EMG were recorded while cats walked on a walkway in three conditions: downslope (−26.6 deg), level (0 deg), and upslope (26.6 deg). The resultant joint moments were calculated using inverse dynamics analysis; length and velocity of major hindlimb muscle-tendon units (MTUs) were calculated using a geometric model and calculated joint angles. It was found that during stance in downslope walking, the MTU stretch of ankle and knee extensors and MTU peak stretch velocities of ankle extensors were significantly greater than those in level or upslope conditions, whereas forces applied to the paw pad and peaks of ankle and hip extensor moments were significantly smaller. The opposite was true for upslope walking. It was suggested that these differences between upslope and downslope walking might affect motion-dependent feedback, resulting in muscle activity changes recorded here or reported in the literature.
Intraspecific variation in morphology and sexual dimorphism in Liolaemus tenuis (Tropiduridae)
Authors: Lamborot Madeleine , Vidal Marcela , Ramírez Claudio , Ortiz Juan Carlos
Published: October 2005

Liolaemus tenuis is a widely distributed arboreal lizard species in central-southern Chile. Although two subspecies, L. t. tenuis and L. t. punctatissimus, have been described based on sexual dimorphism, their characteristic have not been accurately demarcated. Therefore, both traditional and geometric morphometrics were used to study the morphological variation of L. tenuis. Four specific questions were addressed: (1) Does population morphological variation occur along a latitudinal gradient, given its wide geographic distribution in a climactic gradient? (2) Does L. tenuis present sexual dimorphism? (3) In the case of dimorphism, what is the variation along a latitudinal gradient? (4) Are these subspecies morphologically distinguishable? The study was performed in a variety of locations, including the following six bioclimatic regions of Chile: arid mediterranean, semi-arid mediterranean, sub-humid mediterranean, humid mediterranean, per-humid mediterranean, and oceanic with mediterranean influence. Male and female individuals were measured and photographed. Our results suggest sexual dimorphism for all morphological variables analyzed. Geometric data indicate that the eye orbits of the males are more extended than those of the females; this is probably related to territorial defense and/or polygynic mating system. The traditional morphometric approach revealed a difference in individuals from the arid region, whereas the geometric approach revealed a difference in individuals from the oceanic region. Differences in the limits of their distribution ranges seem be related to local factors, such as topography and climatic conditions. Finally, is not possible to recognize distinct subspecies within L. tenuis, and our research concludes that the species consists of one homogenous identity.
The First Wave: Gender Integration and Military Culture
Authors: Titunik Regina F.
Published: October 2005

A number of sexual harassment scandals in the United States armed forces have come to public attention in recent years. Commentators on these scandals have suggested that the incidents are not anomalous, but reflect an institutional culture that generates hostility toward women. The military culture, it is supposed, fosters aggression that is turned against female service members. This article questions such views of the military. It examines the activity of war and its requisites and shows that the military does not foster individual aggression since this quality is, ironically, ineffectual for organized warfare. The examination of gender integration in the armed forces, which follows, brings the complex and multifaceted character of women's involvement in the military into view. Certain aspects of the military culture, the article shows, are congenial to servicewomen and facilitate their often-overlooked successes in this institution.
Civil-Military Relations in Democratizing Indonesia: Change amidst Continuity
Authors: Bilveer Singh
Published: October 2005

The long-standing debate about civil-military relations remains unresolved, especially in light of the third wave of democratization. This study highlights the Indonesian case and its democratization experiment and argues that in spite of changes in civil-military relations during the "third wave," there are certain imperatives that have remained constant. Using Rebecca Schiff's concordance approach, and taking into consideration Indonesia's historical and cultural realities, the article analyzes both the transformation of civilmilitary relations in Indonesia and its limitations. The Indonesian military remains a critical political player in Indonesian politics despite democratization, with a "back to barracks" posture that is unlikely to change in the near future, especially at a time when the country is faced with numerous security challenges and instabilities.
U.S. Military Attitudes Toward Post-Cold War Missions
Authors: Avant Deborah , Lebovic James
Published: October 2005

In this article, we seek to determine whether officers support the post-Cold War's range of new missions and why. To this end, we examine the attitudes of U.S. officers at the command and staff colleges for each service branch. On average, we find that while officers support traditional missions more than new missions, they do support these new missions and believe they address the greatest dangers facing the U.S. We also find that officers are more likely to appreciate the importance of military participation in humanitarian assistance, antiterrorism, and drug interdiction when they serve in a noncombat role, and those who believe that their MOS leads to future career success are more likely to support peace enforcement and peacekeeping. Most significantly, officers' enthusiasm about new missions is linked to their beliefs about civilian attitudes. On average, officers believe that the president supports the entire range of missions. They see Congress and (especially) the public as more suspicious of new missions. Officers are most likely to support new post-Cold War missions when they also believe there is both congressional and public support for them.
Militarized Decision-Making for War in Pakistan: 1947-1971
Authors: Schofield Julian
Published: October 2005

In a balanced, constitutionally governed state, military decision-makers are no more likely to recommend war in a dispute than are civilian leaders. However, in military regimes, there is a tendency to import biases that systematically distort the contribution of a state's foreign and interior ministries. Consequently, military governments become overly pessimistic about the scarcity of security and overconfident about the utility of force. Using the case of war decisions in Pakistan from 1947-1971, this article suggests that the process of militarized decision-making increases the tendency of a military regime to advocate war when isolated from civilian counterbalances.
Bombs for Peace: A Comparative Study of the Use of Air Power in the Balkans
Authors: Forage Paul C.
Published: October 2005

For many decision-makers, precision guided weapons represent what the aerial bomber promised the early air power idealists in the 1930s—a technological solution to difficult wars without the risk of casualties. In 1995, NATO used its air power to bring an end to the war in Bosnia and tried again in 1999 to use bombs to end the conflict in Kosovo. The failure to bring about a quick cessation of the fighting using air power was in part due to misinterpreting the war in Bosnia, as well as misunderstanding, in general, when and where air power is effective.
Complete Access: Women in the Bundeswehr and Male Ambivalence
Authors: Kümmel Gerhard
Published: October 2005

The Bundeswehr is currently undergoing large-scale transformations. Part of the change, which began in January 2001, is that women previously confined to noncombat roles (e.g., medical service; military bands) are now eligible to all classifications and trades within the German armed forces as a consequence of a ruling of the European Court of Justice in January 2000. This seems to indicate that the gender order in Germany, as well as in modern societies in general, is subject to change. Nevertheless, the literature on the integration of women in the armed forces suggests that this step does not meet with fullscale approval. A survey of male Bundeswehr soldiers reveals a good deal of ambivalence, although the data in general seem to document a relatively integration-positive climate in the Bundeswehr. Anticipated positive effects are accompanied by reservations in some segments, and in some more than others. Such attitudes have two sources: one is the traditional image of the soldier, the military and gender roles, and the other is status inconsistency, i.e., a fear of the competition presented by women soldiers. Making female integration a success despite these views requires an unmistakable signal from the political and military leadership that integration is wanted and that it is based on the principles of equality of treatment and of equal opportunity.
The Plight of the Russian Military: Shallow Identity and Self-defeating Culture
Authors: Baev Pavel K.
Published: October 2005

With the arrival of President Putin, the Russian military appeared to overcome the deep structural crisis that had lasted for most of the 1990s. Their identity of a "presidential" institution was reinforced and the contradictory traits in the new military culture were harmonized. That harmony, however, had an unstable foundation of inflated expectations and postponed choices. Putin has produced new blueprints for military reform but the military's bureaucratic self-preservation instinct that had determined the failure of previous efforts is again driving the resistance. The price of failure may be unacceptably high, but Chechnya continues to be a factor that works against downsizing and modernizing the army.
Military and Civilian Dimensions of America's Regional Policy, 1972-1994
Authors: Hooks Gregory
Published: October 2005

This article examines the impact of federal properties on regional growth in the United States between 1972 and 1994, and provides evidence that these properties influenced and continue to influence regional growth. Documenting the impact of federal facilities (military and civilian) on regional growth from 1972 to 1994 allows examination of the differences among types of such facilities. For understanding regional dynamics, those that play a role in the nation's science and technology program—whether military or civilian-have exerted a much stronger force on regional economies than others. The federal government has allocated a very large share of discretionary spending to national security, and thus there are far more national security facilities than there are civilian ones and their collective impact is significantly higher. Nevertheless, if the comparison is made on a per installation basis, individual civilian installations have made a contribution to local economies that is comparable to that of national security facilities.