bluuebunny/crossref_metadata_2025 huggingface dataset:
Monte‐Carlo calculations of the solvent effects on the conformation of angiotensin II
Authors: COLLET OLIVIER , PREMILAT SAMUEL
Published: August 2010

An efficient Metropolis Monte‐Carlo (MMC) procedure is proposed in order to calculate averages of the energy of conformation and structural properties of a polypeptide chain in interaction with a solvent. The contribution of hydration to the free energy of conformation of the macromolecule is calculated using the accessible surface area method. This algorithm, performed with different sets of atomic solvation parameters (ASP), is applied to the peptidic hormone angiotensin II. Different situations of solvation of that molecule are described when the ASP of the polar atoms are fixed to 0, whereas those of the apolar atoms are given values varying from ‐1.0 to 1.0. From results thus obtained, transitions from extended to collapsed conformations of the polypeptide chain can be simulated. Such changes of conformation could be related to a possible mechanism of binding of this hormone on a membrane surface. © Munksgaard 1996.
Phosphoryl transfer reaction regulated by amino acid side chains: A model for phosphoproteins
Authors: ZHAO YU‐FEN , YAN QING‐JIN , WANG QIAN
Published: August 2010

Through a kinetic study of the reaction of phosphoamino acids as incubated in alcohol, it was found that the inter‐ and intramolecular phosphoryl transfer reactions were regiospecific and stereoselective. First, the phosphoryl transfer reaction required the regio‐specifically neighboring α‐carboxy group activation of amino acid but not 8‐carboxy group. The intramolecular side chain catalytic effects relative to hydrogen for N‐phosphoamino acids compared to N‐phosphoglycine were a 119‐ to 4‐times enhancement of the phosphoryl transfer reaction, respectively. Secondly, the intramolecular N→O phosphoryl transfer migration was highly stereoselective, since the reaction rate constant of phosphoallothreonine relative to its diastereomeric threonine was reduced to half. The pentacoordinate transition states modulated by the amino acid side chains were demonstrated by the formation rates of intramolecular pentacoordinate spiro mixed anhydride compounds. © Munksgaard 1996.
The role of oxidative stress in renovascular hypertension
Authors: Campos Ruy R , Oliveira‐Sales Elizabeth B , Nishi Érika E , Boim Mirian A , Dolnikoff Miriam S , Bergamaschi Cássia T
Published: August 2010

1. There is mounting evidence that increased oxidative stress and sympathetic nerve activity play important roles in renovascular hypertension. In the present review, we focus on the importance of oxidative stress in two distinct populations of neurons involved with cardiovascular regulation: those of the rostral ventrolateral medulla (RVLM) and those of the paraventricular nucleus of the hypothalamus (PVN) in the maintenance of sympathoexcitation and hypertension in two kidney–one clip (2K1C) hypertensive rats. Furthermore, the role of oxidative stress in the clipped kidney is also discussed.

2. In the studies reviewed in this article, it was found that hypertension and renal sympathoexcitation in 2K1C rats were associated with an increase in Angiotensin II type one receptor (AT1) expression and in oxidative markers within the RVLM, PVN and in the clipped kidneys of 2K1C rats. Furthermore, acute or chronic anti‐oxidant treatment decreased blood pressure and sympathetic activity, and improved the baroreflex control of heart rate and renal sympathetic nerve activity in 2K1C rats. Tempol or vitamin C administration in the RVLM, PVN or systemically all reduced blood pressure and renal sympathetic activity. Cardiovascular improvement in response to chronic anti‐oxidant treatment was associated with a downregulation of AT1 receptors, as well as oxidative markers in the central nuclei and clipped kidney.

3. The data discussed in the present review support the idea that an increase in oxidative stress within the RVLM, PVN and in the ischaemic kidney plays a major role in the maintenance of sympathoexcitation and hypertension in 2K1C rats.
Multipotent epithelial cells in the process of regeneration and asexual reproduction in colonial tunicates
Authors: Kawamura Kazuo , Sugino Yasuo , Sunanaga Takeshi , Fujiwara Shigeki
Published: August 2010

The cellular and molecular features of multipotent epithelial cells during regeneration and asexual reproduction in colonial tunicates are described in the present study. The epicardium has been regarded as the endodermal tissue‐forming epithelium in the order Enterogona, because only body fragments having the epicardium exhibit the regenerative potential. Epicardial cells in Polycitor proliferus have two peculiar features; they always accompany coelomic undifferentiated cells, and they contain various kinds of organelles in the cytoplasm. During strobilation a large amount of organelles are discarded in the lumen, and then, each tissue‐forming cell takes an undifferentiated configuration. Septum cells in the stolon are also multipotent in Enterogona. Free cells with a similar configuration to the septum inhabit the hemocoel. They may provide a pool for epithelial septum cells. At the distal tip of the stolon, septum cells are columnar in shape and apparently undifferentiated. They are the precursor of the stolonial bud. In Pleurogona, the atrial epithelium of endodermal origin is multipotent. In Polyandrocarpa misakiensis, it consists of pigmented squamous cells. The cells have ultrastructurally fine granules in the cytoplasm. During budding, coelomic cells with similar morphology become associated with the atrial epithelium. Then, cells of organ placodes undergo dedifferentiation, enter a cell division cycle, and commence morphogenesis. Retinoic acid‐related molecules are involved in this dedifferentiation process of multipotent cells. We conclude that in colonial tunicates two systems support the flexibility of tissue remodeling during regeneration and asexual reproduction; dedifferentiation of epithelial cells and epithelial transformation of coelomic free cells.
Habitual physical activity and health in the elderly: The Nakanojo Study
Authors: Aoyagi Yukitoshi , Shephard Roy J
Published: August 2010

This article provides a detailed overview of both factors influencing habitual physical activity, and relationships between such activity and health in the elderly. Current cross‐sectional data from the Nakanojo Study, which we have been carrying out since 2000, indicate substantial associations between the overall health of participants, and both the year‐averaged daily step count and the year‐averaged daily duration of effort undertaken at an intensity >3 metabolic equivalents (MET). In men, the extent of health is associated more closely with the daily duration of activity >3 MET than with the daily step count, whereas in women the association is closer for the step count than for the duration of activity >3 MET. In both sexes, the threshold amount of physical activity associated with better health is greater for physical than for mental benefits: >8000 vs >4000 steps/day and/or >20 vs >5 min/day at >3 MET, respectively. In other words, physical health is better in those spending at least 20 min/day in moderate walking (at a pace of around 1.4 m/s [5 km/h]) and a further >60 min of light activity per day. In contrast, better mental health is associated with much smaller amounts of deliberate physical activity. Both the intensity and the total volume of physical activity are influenced by meteorological factors, particularly precipitation and mean ambient temperature. Activity decreases exponentially to about 4000 steps/day as precipitation increases. Excluding the influence of rainfall, the daily step count peaks at a mean outdoor temperature of around 17°C; above and especially below such readings, physical activity decreases as a quadratic function of temperature. Seasonal changes in the microclimate should thus be considered when designing interventions intended to increase the habitual physical activity of older adults. Based on these findings, we are now developing preventive tactics that should contribute to health promotion, disease prevention and thus a reduction in medical expenses for elderly people. Geriatr Gerontol Int 2010; 10 (Suppl. 1): S236–S243.
Disruption of morphine‐conditioned place preference by a δ2‐opioid receptor antagonist: study of μ‐opioid and δ‐opioid receptor expression at the synapse
Authors: Billa Sophie K. , Xia Yan , Morón Jose A.
Published: August 2010

The addictive properties of morphine limit its clinical use. Learned associations that develop between the abused opiate and the environment in which it is consumed are engendered through Pavlovian conditioning processes. Disruption of the learned associations between the opiate and environmental cues may be a therapeutic approach to prevent morphine dependence. Although a role for the δ‐opioid receptor in the regulation of the rewarding properties of morphine has already been shown, in this study we further characterized the role of the δ‐opioid receptor in morphine‐induced conditioned responses by examining the effect of a selective δ2‐opioid receptor antagonist (naltriben), using a conditioned place preference paradigm in rats. Additionally, we used a subcellular fractionation technique to analyze the synaptic localization of μ‐opioid and δ‐opioid receptors in the hippocampus, in order to examine the molecular mechanisms that may underlie this morphine‐induced conditioned behavior. Our data show that the administration of 1 mg/kg naltriben (but not 0.1 mg/kg) prior to morphine was able to block morphine‐induced conditioned place preference. Interestingly, this naltriben‐induced disruption of morphine conditioned place preference was associated with a significant increase in the expression of the δ‐opioid receptor dimer at the postsynaptic density. In addition, we also observed that morphine conditioned place preference was associated with an increase in the expression of the μ‐opoid receptor in the total homogenate. Overall, these results suggest that modulation of the δ‐opioid receptor expression and its synaptic localization may constitute a viable therapeutic approach to disrupt morphine‐induced conditioned responses.
Effect of low‐dose cisapride on gastric emptying and QTc interval in preterm infants
Authors: Costalos C , Gounaris A , Varhalama E , Kokori F , Alexiou N , Katsarakis I
Published: August 2010

The aim of the study was a prospective survey of the effects of low‐dose cisapride on gastric emptying and QTc interval in very low birthweight infants. Twenty low birthweight infants were studied: mean (SD) gestation 30.5 (2.2) wk; birthweight 1320 (150)g. Gastric emptying was assessed ultrasonically in 15 of these infants, in a randomized blind crossover study, following 24‐h low‐dose oral cisapride administration (0.1 mg/kg given 8 hourly), or placebo. The QTc interval was also determined in all 20 infants following a 7‐d course of cisapride or placebo.

Conclusions: Cisapride significantly shortened both gastric emptying time and QTc interval (p < 0.05) compared to placebo. All infants completed the study without any apparent adverse effects. In conclusion, low‐dose cisapride administration significantly improves gastric emptying without increasing the QTc interval.
Acute rheumatic fever associated with Henoch‐Schönlein purpura: report of three cases and review of the literature
Authors: Eisenstein EM , Navon‐Elkan P
Published: August 2010

Aim: To describe a possible relationship between Henoch‐Schönlein purpura and rheumatic fever. Methods: Patients with features of both diseases were identified by reviewing the hospital records. Medline and reference lists from published articles were used to search for previous reports of the two conditions occurring simultaneously. Results: Three newly described cases, and three previous reports of Henoch‐Schönlein purpura associated with rheumatic carditis or chorea were identified.

Conclusions: The coexistence of these two disorders in some patients supports the view that Group A streptococcus may have a pathogenic role in Henoch‐Schönlein purpura.
Bifurcation Buckling Versus Limit Load Instabilities of
Elastic-Plastic Tubes Under Bending and External Pressure
Authors: Ju G. T. , Kyriakides S.
Published: August 2010

Commonly used procedures for installing offshore pipelines can induce substantial bending to the line in the presence of external pressure. These combined loads can lead to catastrophic collapse of the structure. For typically used steels and higher diameter-to-thickness ratios (D/t), bending is limited by a bifurcation type of instability; for lower D/t values, the structures exhibit limit load types of instabilities. Similar distinctions can be made for bending in the presence of external pressure. Previous work (Corona and Kyriakides, 1988) addressed primarily the limit load types of instabilities. In this paper, this analysis is extended to include bifurcation instabilities. The predictions from the two types of analyses are critically compared to experimental results and recommendations about the regime of applicability of each are made.
On Two Alternative Field Solutions for Second-Order Wave Diffraction
Authors: Cheung K. F. , Isaacson M.
Published: August 2010

The present paper set out a nonlinear boundary value problem involving the interaction of surface waves with large submerged structures in two dimensions. The problem is solved to second order by a time-stepping procedure on the basis of two alternative methods. Both of these involve the application of Green’s theorem, a Taylor series expansion of variables at the free surface and a perturbation series representation of the pertinent variables. Differences between the two solutions are associated with alternative integral equations applicable to second-order terms. The two second-order solutions are compared with each other and with previous theoretical and experimental results, and their applicability is assessed.
Drag Forces and Flow-Induced Vibrations of a Long Vertical Tow Cable—Part II: Unsteady Towing Conditions
Authors: Grosenbaugh M. A. , Yoerger D. R. , Hover F. S. , Triantafyllou M. S.
Published: August 2010

Full-scale experimental data on the dynamics and flow-induced vibrations of a long vertical tow cable are analyzed. The data were measured while the surface ship was going through a series of starting, stopping, and backing maneuvers. The results of the study show that the amplitude of the flow-induced vibrations of the cable is strongly modulated during maneuvering operations. Maneuvering creates situations where different sections of the cable are translating at different speeds. This causes an “artificial” shear current which at times is severe, depending on the difference in speed between the top and bottom of the cable. The artificial shear is responsible for the intensification of the amplitude modulation above the level that is observed during steady-state towing conditions. The overall effect of the amplitude modulation is a reduction in the hydrodynamic drag forces. It is shown that the drag coefficient measured during maneuvering operations is lower than the steady-state value.
Submerged Floating Breakwaters
Authors: Evans D. V. , Linton C. M.
Published: August 2010

In this paper we show how a submerged body can, if properly tuned to the incoming waves, reflect an appreciable amount of the incident wave energy by creating waves through its own motion which effectively cancel the incident waves passing over it. A general theory for this phenomenon is described which is applied to the cases of a hinged vertical plate and a submerged tethered horizontal circular cylinder.
Efficient Static Analysis and Design of Flexible Risers
Authors: Riggs H. R. , Leraand T.
Published: August 2010

An improved cable element for static analysis is presented based on the equations of an elastic catenary. The element includes an algorithm for adaptive discretization when fluid drag forces are present. Hence, a single element can be used to model many marine cables, regardless of length. The element is applied to flexible riser analysis and preliminary design, which is automated by solving a nonlinear programming problem. Results demonstrate that a practical automated design method can be developed following the procedure presented here.
The Ergodicity Assumption for Sea States in the Reliability Estimation of Offshore Structures
Authors: Schall G. , Faber M. H. , Rackwitz R.
Published: August 2010

Various schemes for the computation of structural reliability in the presence of ergodic wave load processes, ergodic sea-state sequences and simple (nonergodic) random variables such as strength parameters or statistical uncertainties are investigated for both nondeteriorating and deteriorating structural properties. It is assumed that at least conditional outcrossing rates can be computed. It is found that rigorous formulations can require substantial numerical effort even in the context of FORM / SORM computation schemes as they require nested integration. However, for high reliability and not too large variabilities of the nonergodic variables, simpler computation schemes can be used. In the nondeteriorating case, the ergodic theorem can be used with advantage, while in the deteriorating case, Jensen’s inequality can be applied to arrive at simple and appropriate computation schemes.
An Examination of the Influence of Strain Rate on Subfailure Mechanical Properties of the Annulus Fibrosus
Authors: Gregory Diane E. , Callaghan Jack P.
Published: August 2010

Disk herniation is often considered a cumulative injury in that repetitive stress on the posterior annulus can result in the nucleus pulposus penetrating the annulus fibrosus and eventually extruding posteriorly. Further, it has been documented that the nucleus pulposus works its way through the annulus through clefts, which form as a result of repetitive tensile strain. The annulus fibrosus is viscoelastic in nature and therefore could express different mechanical responses to applied strain at varying rates. Other viscoelastic tissues, including tendons and ligaments, have shown altered mechanical responses to different rates of applied strain, but the response of the annulus to varying rates of strain is largely unknown. The present study examined the mechanical properties of 20 two-layered samples of porcine annulus fibrosus tissue at three distinct rates of applied 20% biaxial strain (20% strain over 20 s (slow), over 10 s (medium), and over 5 s (fast)); these three rates are considered applicable to nontraumatic loading. No differences in the stiffness or maximum stress in each of the two directions of applied strain were observed between the three strain rates. Specifically, the average (standard deviation) moduli calculated at the fast, medium, and slow rates, respectively, in the axial direction were 7.42 MPa (6.06), 7.77 MPa (6.61), and 7.63 MPa (6.67) and 8.22 MPa (8.4), 8.63 MPa (9.00), and 8.49 MPa (8.69) in the circumferential direction. The maximum stress values reached during the fast, medium, and slow rates, respectively, in the axial direction were 0.40 (0.36) MPa, 0.40 (0.36) MPa, and 0.39 (0.35) MPa and 0.45 (0.47) MPa, 0.44 (0.46) MPa, and 0.43 (0.46) MPa in the circumferential direction. At submaximal strain magnitudes over a range of nontraumatic rates likely to result in clefts in the annulus and potentially leading to disk herniation, any strain rate dependence is not significant.
The Contribution of the Perichondrium to the Structural Mechanical Behavior of the Costal-Cartilage
Authors: Forman Jason L. , del Pozo de Dios Eduardo , Dalmases Carlos Arregui , Kent Richard W.
Published: August 2010

The costal-cartilage in the human ribcage is a composite structure consisting of a cartilage substance surrounded by a fibrous, tendonlike perichondrium. Current computational models of the human ribcage represent the costal-cartilage as a homogeneous material, with no consideration for the mechanical contributions of the perichondrium. This study sought to investigate the role of the perichondrium in the structural mechanical behavior of the costal-cartilage. Twenty-two specimens of postmortem human costal-cartilage were subjected to cantileveredlike loading both with the perichondrium intact and with the perichondrium removed. The test method was chosen to approximate the cartilage loading that occurs when a concentrated, posteriorly directed load is applied to the midsternum. The removal of the perichondrium resulted in a statistically significant (two-tailed Student’s t-test, p≤0.05) decrease of approximately 47% (95% C.I. of 35–58%) in the peak anterior-posterior reaction forces generated during the tests. When tested with the perichondrium removed, the specimens also exhibited failure in the cartilage substance in the regions that experienced tension from bending. These results suggest that the perichondrium does contribute significantly to the stiffness and strength of the costal-cartilage structure under this type loading, and should be accounted for in computational models of the thorax and ribcage.
Echolocation clicks of free-ranging Chilean dolphins (Cephalorhynchus eutropia)
Authors: Götz Thomas , Antunes Ricardo , Heinrich Sonja
Published: August 2010

In this paper, evidence is provided that Chilean dolphins (Cephalorhynchus eutropia) produce ultrasonic echolocation clicks of the narrow-band high-frequency category. Echolocation clicks emitted during approaches of the hydrophones consisted only of narrow-band (rms-BW: 12.0 kHz) single pulses with mean centroid frequencies of about 126 kHz, peak frequencies of 126 kHz, and a 20 dB duration of 82.6 μs. The maximum received level measured exceeded 165 dB re 1 μPa. In addition, high repetition-rate buzzes were recorded during foraging behavior (click interval: 2 ms), but no whistles or calls with tonal components were detected.
Low-frequency sound speed and attenuation in sandy seabottom from long-range broadband acoustic measurements
Authors: Wan Lin , Zhou Ji-Xun , Rogers Peter H.
Published: August 2010

A joint China-U.S. underwater acoustics experiment was conducted in the Yellow Sea with a very flat bottom and a strong and sharp thermocline. Broadband explosive sources were deployed both above and below the thermocline along two radial lines up to 57.2 km and a quarter circle with a radius of 34 km. Two inversion schemes are used to obtain the seabottom sound speed. One is based on extracting normal mode depth functions from the cross-spectral density matrix. The other is based on the best match between the calculated and measured modal arrival times for different frequencies. The inverted seabottom sound speed is used as a constraint condition to extract the seabottom sound attenuation by three methods. The first method involves measuring the attenuation coefficients of normal modes. In the second method, the seabottom sound attenuation is estimated by minimizing the difference between the theoretical and measured modal amplitude ratios. The third method is based on finding the best match between the measured and modeled transmission losses (TLs). The resultant seabottom attenuation, averaged over three independent methods, can be expressed as α=(0.33±0.02)f1.86±0.04(dB/m kHz) over a frequency range of 80–1000 Hz.
Geoacoustic inversion with two source-receiver arrays in shallow water
Authors: Sukhovich Alexey , Roux Philippe , Wathelet Marc
Published: August 2010

A geoacoustic inversion scheme based on a double beamforming algorithm in shallow water is proposed and tested. Double beamforming allows identification of multi-reverberated eigenrays propagating between two vertical transducer arrays according to their emission and reception angles and arrival times. Analysis of eigenray intensities yields the bottom reflection coefficient as a function of angle of incidence. By fitting the experimental reflection coefficient with a theoretical prediction, values of the acoustic parameters of the waveguide bottom can be extracted. The procedure was initially tested in a small-scale tank experiment for a waveguide with a Plexiglas bottom. Inversion results for the speed of shear waves in Plexiglas are in good agreement with the table values. A similar analysis was applied to data collected during an at-sea experiment in shallow coastal waters of the Mediterranean. Bottom reflection coefficient was fitted with the theory in which bottom sediments are modeled as a multi-layered system. Retrieved bottom parameters are in quantitative agreement with those determined from a prior inversion scheme performed in the same area. The present study confirms the interest in processing source–receiver array data through the double beamforming algorithm, and indicates the potential for application of eigenray intensity analysis to geoacoustic inversion problems.
Analytical model of internally coupled ears
Authors: Vossen Christine , Christensen-Dalsgaard Jakob , Leo van Hemmen J.
Published: August 2010

Lizards and many birds possess a specialized hearing mechanism: internally coupled ears where the tympanic membranes connect through a large mouth cavity so that the vibrations of the tympanic membranes influence each other. This coupling enhances the phase differences and creates amplitude differences in the tympanic membrane vibrations. Both cues show strong directionality. The work presented herein sets out the derivation of a three dimensional analytical model of internally coupled ears that allows for calculation of a complete vibration profile of the membranes. The analytical model additionally provides the opportunity to incorporate the effect of the asymmetrically attached columella, which leads to the activation of higher membrane vibration modes. Incorporating this effect, the analytical model can explain measurements taken from the tympanic membrane of a living lizard, for example, data demonstrating an asymmetrical spatial pattern of membrane vibration. As the analytical calculations show, the internally coupled ears increase the directional response, appearing in large directional internal amplitude differences (iAD) and in large internal time differences (iTD). Numerical simulations of the eigenfunctions in an exemplary, realistically reconstructed mouth cavity further estimate the effects of its complex geometry.
The auditory brainstem response in two lizard species
Authors: Brittan-Powell Elizabeth F. , Christensen-Dalsgaard Jakob , Tang Yezhong , Carr Catherine , Dooling Robert J.
Published: August 2010

Although lizards have highly sensitive ears, it is difficult to condition them to sound, making standard psychophysical assays of hearing sensitivity impractical. This paper describes non-invasive measurements of the auditory brainstem response (ABR) in both Tokay geckos (Gekko gecko; nocturnal animals, known for their loud vocalizations) and the green anole (Anolis carolinensis, diurnal, non-vocal animals). Hearing sensitivity was measured in 5 geckos and 7 anoles. The lizards were sedated with isoflurane, and ABRs were measured at levels of 1 and 3% isoflurane. The typical ABR waveform in response to click stimulation showed one prominent and several smaller peaks occurring within 10 ms of the stimulus onset. ABRs to brief tone bursts revealed that geckos and anoles were most sensitive between 1.6–2 kHz and had similar hearing sensitivity up to about 5 kHz (thresholds typically 20–50 dB SPL). Above 5 kHz, however, anoles were more than 20 dB more sensitive than geckos and showed a wider range of sensitivity (1–7 kHz). Generally, thresholds from ABR audiograms were comparable to those of small birds. Best hearing sensitivity, however, extended over a larger frequency range in lizards than in most bird species.
Fast inverse scattering solutions using the distorted Born iterative method and the multilevel fast multipole algorithm
Authors: Hesford Andrew J. , Chew Weng C.
Published: August 2010

The distorted Born iterative method (DBIM) computes iterative solutions to nonlinear inverse scattering problems through successive linear approximations. By decomposing the scattered field into a superposition of scattering by an inhomogeneous background and by a material perturbation, large or high-contrast variations in medium properties can be imaged through iterations that are each subject to the distorted Born approximation. However, the need to repeatedly compute forward solutions still imposes a very heavy computational burden. To ameliorate this problem, the multilevel fast multipole algorithm (MLFMA) has been applied as a forward solver within the DBIM. The MLFMA computes forward solutions in linear time for volumetric scatterers. The typically regular distribution and shape of scattering elements in the inverse scattering problem allow the method to take advantage of data redundancy and reduce the computational demands of the normally expensive MLFMA setup. Additional benefits are gained by employing Kaczmarz-like iterations, where partial measurements are used to accelerate convergence. Numerical results demonstrate both the efficiency of the forward solver and the successful application of the inverse method to imaging problems with dimensions in the neighborhood of ten wavelengths.
Effects of filtering of harmonics from biosonar echoes on delay acuity by big brown bats (Eptesicus fuscus)
Authors: Bates Mary E. , Simmons James A.
Published: August 2010

Big brown bats emit FM biosonar sounds containing two principal harmonics (FM1∼55–22 kHz;FM2∼105–45 kHz). To examine the role of harmonics, they were selectively filtered from stimuli in electronic-echo delay discrimination experiments. Positive stimuli were delayed by 3.16 ms (55 cm simulated target range); negative stimuli were by delayed by 3.96 ms (68 cm). This large 800-μs delay difference (nearly 14 cm) was easily discriminated for echoes containing equal-strength FM1 and FM2. Performance gradually decreased as highpass filters removed progressively larger segments from FM1. For echoes with FM2 alone, performance collapsed to chance, but performance remained good for lowpass echoes containing FM1 alone. Attenuation of FM2 by 3 dB relative to FM1 also decreased performance, but shortening electronic delay of the attenuated FM2 by 48 μs counteracted amplitude-latency trading and restored performance. Bats require the auditory representations of FM1 and FM2 to be in temporal register for high delay acuity. Misalignment of neuronal responses degrades acuity, but outright removal of FM2, leaving only FM1, causes little loss of acuity. Functional asymmetry of harmonics reflects lowpass effects from beaming and atmospheric propagation, which leave FM1 intact. It may cooperate with latency shifts to aid in suppression of clutter.
Theoretical study and synthesis of the reaction between triphenylphosphine, dialkyl acetylenedicarboxylates and 2-aminobenzimidazole, 2-hydroxy-3-nitropyridine or 1,2,3,4-tetrahydrocarbazole
Authors: Habibi-Khorassani Sayyed Mostafa , Maghsoodlou Malek Taher , Ebrahimi Ali , Heydari Reza , Hazeri Nourollah , Kazemian Mohammad Amin , Nassiri Mahmoud , Adrom Belghais , Zakarianejad Mohammad
Published: August 2010

Triphenylphosphine reacts with dialkyl acetylenedicarboxylates in the presence of heterocyclic compounds, such as 2-aminobenzimidazole, 2-hydroxy-3-nitropyridine or 1,2,3,4-tetrahydrocarbazole to generate stable phosphorus ylides. Some ylides exist in solution as a mixture of two geometrical isomers as a result of restricted rotation around the carbon–carbon partical double bond resulting from conjugation of the ylide moiety with the adjacent carbonyl group, whereas others occur as a single isomer only. For this reason, the assignments of more stable Z- or E-isomers as the major or minor forms were investigated using theoretical calculations.
Estimates of drowning morbidity and mortality adjusted for exposure to risk
Authors: Mitchell Rebecca J , Williamson Ann M , Olivier Jake
Published: August 2010

Objectives

To estimate the rate of unintentional drowning mortality and hospitalised morbidity using population-based, population-risk and person-time denominator data and to compare the estimates obtained. To then compare exposure-based rates for drowning with road traffic death rates.

Method

Retrospective analysis of unintentional drowning mortality and hospitalised morbidity of New South Wales (NSW, Australia) residents 16+ years of age during 1 January to 31 December 2005. Information on population-risk and person-time risk was obtained from the 2005 NSW Population Health Survey. Analysis of road traffic death data from NSW and population and person-time risk estimates from the Survey of Vehicle Use, Household Travel Surveys and Roads and Traffic Authority Speed Surveys in 2005.

Results

Estimated drowning mortality and hospitalised morbidity rates for adults were higher using population-risk and person-time risk exposures compared to a population-based exposure. Population-based estimates of road traffic mortality were four times higher than drowning mortality rates. In contrast, exposure adjusted person-time estimates for drowning were 200 times higher than road traffic fatalities.

Conclusions

Many injury risks are underestimated when the total age-specific population is used to calculate an injury rate instead of actual population-risk or person-time exposure. This can result in the identification of misleading priorities for injury prevention. Drowning risk is strikingly higher than previously thought based on population-based estimates. This information is important for decision-making and policy development as it provides a basis for comparing the inherent risk in exposure to hazards with potential to cause injury.
Positioning of the Fermi Level in Graphene Devices with Asymmetric Metal Electrodes
Authors: Kim Bum-Kyu , Jeon Eun-Kyoung , Kim Ju-Jin , Lee Jeong-O
Published: August 2010

To elucidate the effect of the work function on the position of the Dirac point, we fabricated graphene devices with asymmetric metal contacts. By measuring the peak position of the resistance for each pair of metal electrodes, we obtained the voltage of the Dirac point (V) from the gate response. We found that the position of (V) in the hybrid devices was significantly influenced by the type of metal electrode. The measured shifts in (V) were closely related to the modified work functions of the metal‐graphene complexes. Within a certain bias range, the Fermi level of one of the contacts aligned with the electron band and that of the other contact aligned with the hole band.
Unifocal Granuloma of Femur due to Langerhans' Cell Histiocytosis: A Case Report and Review of the Literature
Authors: Singh Harpreet , Kaur Satnam , Yuvarajan P. , Jain Nishant , Maini Lalit
Published: August 2010

The radiological diagnosis of osteolytic lesions of the long bones in pediatric population constitutes a challenge when the case history and clinical data are uncharacteristic. We believe that the description of few clinically and histologically proven cases to verify the existence of radiological signs useful for diagnosis may be of interest. Here, we describe a case of Langerhans' cell histiocytosis (LCH) presenting as unifocal eosinophilic granuloma of femur along with a brief review of the literature.
Syndrome of Inappropriate Secretion of Antidiuretic Hormone Cholestasis and Pericardial Effusion Due to Brucellosis Infection: A Case Report
Authors: Dülger Ahmet Cumhur , Kemik Özgür , Sümer Aziz , Akdeniz Hüseyin , Küçükoğlu Mehmet Emin , Canbaz Esra Turan , Itik Veyis , Aytemiz Enver
Published: August 2010

Syndrome of inappropriate secretion of antidiuretic hormone (SIADH) is an extremely rare complication of infectious diseases. A rare case of brucellosis complicated by syndrome of inappropriate secretion of antidiuretic hormone (SIADH) cholestasis and pericardial involvement is reported. A 27-year-old woman was admitted for fever, abdominal pain, and scleral icterus. Her medical history revealed no recent use of diuretic agents. In addition to cholestasis and elevated liver enzymes, euvolemic hyponatremia, hypouricemia, low plasma osmolality, and high urinary osmolality were also detected. Surrenal and thyroid tests were also within normal range. Echocardiography revealed minimal pericardial effusion with normal cardiac functions. The final diagnosis was SIADH due to Brucellosis. Hyponatremia, cholestasis, and pericardial disease were resolved with effective antibrucellar treatment with streptomycine and doxycycline. After completing treatment of brucellosis, there was not any more evidence of cholestasis and pericardial fluid.
Understanding of Abdominal Compartment Syndrome among Pediatric Healthcare Providers
Authors: Ejike J. Chiaka , Newcombe Jennifer , Baerg Joanne , Bahjri Khaled , Mathur Mudit
Published: August 2010

Background. The sparse reporting of abdominal compartment syndrome (ACS) in the pediatric literature may reflect inadequate awareness and recognition among pediatric healthcare providers (HCP).Purpose. To assess awareness of ACS, knowledge of the definition and intraabdominal pressure (IAP) measurement techniques used among pediatric HCP.Method. A written survey distributed at two pediatric critical care conferences.Results. Forty-seven percent of 1107 questionnaires were completed. Participants included pediatric intensivists, pediatric nurses, and others. Seventy-seven percent () of participants had heard of ACS. Only 46.8% defined ACS correctly. The threshold IAP value used to define ACS was variable among participants. About one-quarter of participants (83/343), had never measured IAP.Conclusion. Twenty-three percent of HCP surveyed were unaware of ACS. Criteria used to define ACS were variable. Focused education on recognition of ACS and measuring IAP should be promoted among pediatric HCP.
Effects of Oral, Vaginal, and Transdermal Hormonal Contraception on Serum Levels of Coenzyme Q10, Vitamin E, and Total Antioxidant Activity
Authors: Palan Prabhudas R. , Strube Felix , Letko Juraj , Sadikovic Azra , Mikhail Magdy S.
Published: August 2010

The use of the transdermal contraceptive patch is associated with greater bioavailability of ethinyl estradiol (EE) compared with contraceptive vaginal ring or oral contraceptives (OC). We compared the influences of three contraceptive methods (OC, vaginal ring, and transdermal patch) on serum levels of coenzyme Q10, α‐tocopherol, γ‐tocopherol and total antioxidant capacity in premenopausal women. Blood samples from 30 premenopausal women who used hormonal contraception for at least 4 months were collected. Forty subjects who did not use any contraception were studied as control. Serum levels of coenzyme Q10, α‐tocopherol and γ‐tocopherol were measured by high‐pressure liquid chromatography. Serum samples were also assayed for total
antioxidant capacity (TAOC). Serum levels of coenzyme Q10 and α‐tocopherol were found to be significantly lower (P < .05) in all three contraceptive users compared with controls. Contraceptive patch users had the lowest levels of
coenzyme Q10 levels compared with normal subjects. Serum TAOC levels were significantly lower (P < .05) among the contraceptive user groups. Alterations in coenzyme Q10 and α‐tocopherol induced by hormonal contraception and the potential effect(s) of exogenous ovarian hormones should be taken into consideration in future antioxidant research.
Molecular Markers Implicating Early Malignant Events in Cervical Carcinogenesis
Authors: Koskimaa Hanna-Mari , Kurvinen Kaisa , Costa Silvano , Syrjänen Kari , Syrjänen Stina
Published: August 2010

Background: Human papillomavirus can induce a stepwise progression of precursor lesions to carcinoma. Sensitive and specific molecular markers are needed to identify the cervical lesions (CIN) at risk for this progression. hTERT activation could be one indicator of a point of no return in malignant progression.

Methods: The UT-DEC-1 cell line is an in vitro model for the study of human papillomavirus–induced progression. Using molecular mining, nine potential genes interlinking hTERT and viral oncogene expression with the phenotypical features of CIN2 were identified. After preliminary testing with real-time PCR, five genes were selected for further analysis: hTERT, DKC1, Bcl-2, S100A8, and S100A9. These proteins were also tested in a series of 120 CIN lesions using immunohistochemistry.

Results: Analysis of the mRNA expression of these genes at different cell passages revealed three time points with significant changes. hTERT, Bcl-2, and S100A9 were also overexpressed in CIN lesions, and the expression pattern changed during the progression toward CIN3 lesions.

Conclusions: These identified time points that were combined with the mRNA overexpression of target genes matched events previously shown to be important in the progression toward malignancy: (a) the viral integration into the cell genome and episome loss; (b) the selection of cells with an acquired growth advantage and ability to maintain telomerase activity; and (c) the final stage of malignancy with permanently upregulated telomerase.

Impact: hTERT, Bcl-2, and S100A9 together might compose a potential prognostic marker panel for the assessment of CIN lesions. These results, however, need further validation in prospective clinical settings. Cancer Epidemiol Biomarkers Prev; 19(8); 2003–12. ©2010 AACR.
Characteristics and Determinants of Adiposity in Pediatric Cancer Survivors
Authors: Miller Tracie L. , Lipsitz Stuart R. , Lopez-Mitnik Gabriela , Hinkle Andrea S. , Constine Louis S. , Adams M. Jacob , French Carol , Proukou Cynthia , Rovitelli Amy , Lipshultz Steven E.
Published: August 2010

Background: Adiposity and the diseases associated with it, including cardiovascular disease, are emerging long-term complications of pediatric cancer survivors. Direct evaluations of adiposity and comparisons to contemporary controls that can differentiate recent trends in obesity from cancer-related treatments and sequelae are limited.

Methods: We evaluated demographic, treatment, lifestyle, and endocrine factors at the time of dual-energy X-ray absorptiometry testing in 170 non-Hispanic white survivors and 71 sibling controls, and compared three measures of adiposity [body mass index (BMI), total body fat, and trunk fat]. For the survivors alone, we determined factors independently associated with BMI and body fat.

Results: Survivors were at 12 years since diagnosis; 58% had leukemia or lymphoma. BMI did not differ between groups. Among males, body fat was greater in survivors than in controls (25.8% versus 20.7%; P = 0.007), as was trunk fat (26.7% versus 21.3%; P = 0.008). Total or trunk fat did not differ among females. Cholesterol, triglycerides, low-density lipoprotein cholesterol, and television viewing hours were higher among male survivors than in controls. Independent factors associated with higher BMI and total and trunk fat included any cranial radiation and television viewing hours, whereas prior treatment with cyclophosphamide was associated with lower BMI and body fat measures.

Conclusions: Compared with siblings, male survivors have greater body fat and metabolic risks. Cranial irradiation and television hours are important risk factors for adiposity in pediatric cancer survivors.

Impact: Pediatric cancer survivors should be carefully monitored for cardiovascular risk factors and sedentary lifestyles. Cancer Epidemiol Biomarkers Prev; 19(8); 2013–22. ©2010 AACR.
Polymorphisms at the Microseminoprotein-β Locus Associated with Physiologic Variation in β-Microseminoprotein and Prostate-Specific Antigen Levels
Authors: Xu Xing , Valtonen-André Camilla , Sävblom Charlotta , Halldén Christer , Lilja Hans , Klein Robert J.
Published: August 2010

Background: rs10993994, a single nucleotide polymorphism (SNP) at the genetic locus encoding β-microseminoprotein (β-MSP), is associated with both prostate cancer risk and levels of blood prostate-specific antigen (PSA), a biomarker used in prostate cancer screening. Therefore, we wished to determine the association between SNPs at MSMB, the gene encoding β-MSP, and the levels of prostate-produced biomarkers β-MSP, PSA, and human kallikrein 2 (hK2) in blood and semen.

Methods: Blood and semen from 304 healthy young Swedish men (ages 18-21) were assayed for β-MSP, PSA, and hK2. SNPs around MSMB were genotyped from matched DNA and analyzed for quantitative association with biomarker levels. Empirical P values were multiple test–corrected and the independence of each SNP's effect was determined.

Results: rs10993994 was significantly associated with the blood and semen levels of β-MSP (both P < 1.0 × 10−7) and PSA (P = 0.00014 and P = 0.0019), and semen levels of hK2 (P = 0.00027). Additional copies of the prostate cancer risk allele resulted in lower β-MSP but higher PSA levels, and singly explained 23% and 5% of the variation seen in semen β-MSP and PSA, respectively. Additional SNPs at MSMB are associated with β-MSP and PSA independently of rs10993994.

Conclusions: SNPs at MSMB correlate with physiologic variation in β-MSP and PSA levels in the blood and semen of healthy young Swedish men. In particular, rs10993994 has a strong effect on β-MSP levels.

Impact: Our results suggest a mechanism by which rs10993994 might predispose to prostate cancer and raise the possibility that genetic variation might need to be considered in interpreting the levels of these biomarkers. Cancer Epidemiol Biomarkers Prev; 19(8); 2035–42. ©2010 AACR.
Children with 45,X/46,XY Karyotype from Birth to Adult Height
Authors: Tosson Hanan , Rose Susan R. , Gartner Lou Ann
Published: August 2010

Background: Growth pattern of children with 45,X/46,XY karyotype (X/XY children) has not been characterized. Objective: Our objective is to describe growth pattern and long-term outcome of X/XY children and to develop guidelines for management of their short stature. Our hypothesis was that abnormal karyotype and deficiency of gonadal function might play a role in growth deceleration in X/XY children. Methods: Retrospective record review and cohort follow-up of X/XY children were conducted between January 2005 and August of 2009. Sixteen X/XY children were evaluated and managed at a single institution as part of standard clinical care as established at the time between 1969 and 2009. The main outcome measures were clinical presentation, clinical characteristics, growth pattern, radiologic studies, pathological studies, and endocrine function of X/XY children. Results: Only X/XY female children underwent bilateral gonadectomy. As a group, X/XY female children were shorter at all age groups and at adult height relative to X/XY male children. Both groups manifested growth deceleration rather than growth spurt at the time of puberty. In both groups, adult height was compromised relative to mid-parental height. Conclusions: X/XY children, similar to girls with Turner syndrome, benefit from growth hormone treatment. Deficiencies of both hypothalamic gonadal axis and primary gonadal function appear to play a role in their growth deceleration. Sex steroid replacement at the time of puberty has an important role in management.
Telomere Capture as a Frequent Mechanism for Stabilization of the Terminal Chromosomal Deletion Associated with Inverted Duplication
Authors: Yu S. , Graf W.D.
Published: August 2010

We report 4 interstitial inverted duplications with associated terminal deletions (inv dup del) involving the short arms of chromosomes 5 and 8, and the long arm of chromosome 13 by microarray-based comparative genomic hybridization (aCGH) combined with chromosome banding (GTG banding) and fluorescence in situ hybridization (FISH) analyses. Formation of the intermediate dicentric chromosomes in 3 of them occurred through breakage-fusion-bridge cycle mechanism (U-type exchange mechanism) and in the fourth one it occurred through the mediation of the inverted low-copy repeats on chromosome 8p23.1. Two of these 4 inv dup del were confirmed and a third one was suspected to be associated with telomere capture for the healing of the terminal deletions. These findings indicate that a telomere capture mechanism is frequently used for stabilizing the broken chromosome ends in this type of genomic rearrangements. In addition, the inv dup del(13) represents the first observation of inv dup del on chromosome 13 in humans, the inv dup del(5) represents the first observation of inv dup del(5p) with an associated telomere capture, and unique features of the remaining two inv dup del(8p) were also discussed.