bluuebunny/crossref_metadata_2025_split huggingface dataset:
Regenerating the periodontium: is there a magic formula?
Authors: Foster BL , Somerman MJ 
Published: October 2005

Structured AbstractAuthors –  Foster BL, Somerman MJObjective –  Left untreated, periodontal disease results in destruction of periodontal tissues including cementum, bone and the periodontal ligament, and subsequently, tooth loss. Increased research efforts focused on understanding periodontal disease at the cellular, molecular and clinical level have resulted in improved modalities for arresting disease progression; however, outcomes of existing procedures are not predictable and often disappointing. Critical to improving the predictability of regenerative therapies is targeting studies toward enhancing our understanding of the cellular and molecular events required to restore periodontal tissues.Design –  Toward this goal our laboratory has focused on defining cells, mechanisms and factors regulating development of periodontal tissues, using in vitro and in vivo rodent models.Results and Conclusion –  Results from these studies have enabled us to identify attractive candidate factors/cells including: 1) products secreted by epithelial cells that act on mesenchymal cells (amelogenins): we observed that both follicle cells and cementoblasts are responsive to amelogenin‐like molecules resulting in changes in the expression of genes associated with cell maturation; 2) morphogens (bone morphogenetic proteins, BMP): we report that follicle cells respond differently to BMPs vs. cementoblasts, depending on dose of and specific BMP used; 3) phosphates: existing data suggest that phosphates act as signaling molecules regulating the expression of genes associated with cementoblast maturation. Knowledge gained from these studies has provided insight as to the cells/factors required for designing improved regenerative therapies.
Design and assessment of a tissue‐engineered model of human phalanges and a small joint
Authors: Landis WJ , Jacquet R , Hillyer J , Lowder E , Yanke A , Siperko L , Asamura S , Kusuhara H , Enjo M , Chubinskaya S , Potter K , Isogai N 
Published: October 2005

Structured AbstractAuthors –  Landis WJ, Jacquet R, Hillyer J, Lowder E, Yanke A, Siperko L, Asamura S, Kusuhara H, Enjo M, Chubinskaya S, Potter K, Isogai N.Objectives –  To develop models of human phalanges and small joints by suturing different cell‐polymer constructs that are then implanted in athymic (nude) mice.Design –  Models consisted of bovine periosteum, cartilage, and/or tendon cells seeded onto biodegradable polymer scaffolds of either polyglycolic acid (PGA) or copolymers of PGA and poly‐L‐lactic acid (PLLA) or poly‐ɛ‐caprolactone (PCL) and PLLA. Constructs were fabricated to produce a distal phalanx, middle phalanx, or distal interphalangeal joint.Setting and Sample Population –  Studies of more than 250 harvested implants were conducted at the Northeastern Ohio Universities College of Medicine.Experimental Variable –  Polymer scaffold, cell type, and implantation time were examined.Outcome Measure –  Tissue‐engineered specimens were characterized by histology, transmission electron microscopy, in situ hybridization, laser capture microdissection and qualitative and quantitative polymerase chain reaction analysis, magnetic resonance microscopy, and X‐ray microtomography.Results –  Over periods to 60 weeks of implantation, constructs developed through vascularity from host mice; formed new cartilage, bone, and/or tendon; expressed characteristic genes of bovine origin, including type I, II and X collagen, osteopontin, aggrecan, biglycan, and bone sialoprotein; secreted corresponding proteins; responded to applied mechanical stimuli; and maintained shapes of human phalanges with small joints.Conclusion –  Results give insight into construct processes of tissue regeneration and development and suggest more complete tissue‐engineered cartilage, bone, and tendon models. These should have significant future scientific and clinical applications in medicine, including their use in plastic surgery, orthopaedics, craniofacial reconstruction, and teratology.
Polymorphism of Endothelial Nitric Oxide Synthase Gene in Patients with Erectile Dysfunction
Authors: Erkan Erkan , Muslumanoglu Ahmet Yaser , Oktar Tayfun , Sanli Oner , Ozbek Uður , Kadioglu Ates 
Published: October 2005

ABSTRACT

Introduction
Endothelial-derived nitric oxide (NO), which is produced by endothelial nitric oxide synthase (eNOS) in response to increased blood flow, maintains the tumescence phase of erection. The eNOS gene is located on the seventh somatic chromosome and the polymorphism of this gene has been reported to cause changes in the structure of enzyme system, resulting in disturbance of its activity.

Aim
The aim of this prospective study is to evaluate the relationship between polymorphism of eNOS gene and erectile dysfunction (ED).

Methods
Thirty patients with ED (mean age: 58.7 ± 9.97, range: 39–74 years) and 25 voluntary controls (mean age: 56.44 ± 7.58, range: 47–72 years) were enrolled to the study. Patients with ED were evaluated with International Index of Erectile Function (IIEF) questionnaire, routine blood tests for systemic vascular risk factors, and color Doppler ultrasonography while potency of the control group were only assessed with IIEF questionnaire. The presence of polymorphism of eNOS gene was determined in both groups by polymerase chain reaction in the fourth intron of the seventh somatic chromosome that encodes eNOS gene.

Results
The incidences of diabetes mellitus and coronary artery disease were statistically higher in the ED group (P = 0.023 and 0.029, respectively) while mean IIEF score was significantly lower (P = 0.001). Evaluation with color Doppler ultrasonography revealed penile arterial insufficiency in six cases, cavernosal insufficiency in 19 cases, and mixed vascular insufficiency in five cases. The distributions of three eNOS genotypes (eNOS4b/b, eNOS4a/b, and eNOS4a/a) among ED patients and controls were similar (P &gt; 0.05). However, eNOS4a/b genotype was statistically higher in diabetics (P = 0.042). Also, 80% of the patients with severe ED and 54.5% of the diabetic patients with ED had eNOS4a/b genotype.

Conclusion
In our study, no correlation was detected between the polymorphism of eNOS gene and ED. However, 80% of the patients with severe ED and 54.5% of the diabetic patients with ED had eNOS4a/b genotype. Based on our data, it seems that diabetic patients with ED tend to have more eNOS4a/b genotype.
The perceptual dimensions of single-electrode and nonsimultaneous dual-electrode stimuli in cochlear implantees
Authors: McKay Colette M. , McDermott Hugh J. , Clark Graeme M. 
Published: October 2005

The perceptual dimensions evoked by dual-electrode stimulation were investigated in four cochlear implantees. The dual-electrode stimulation consisted of biphasic current pulse trains, such that two intracochlear electrodes each received one pulse in a 250-Hz cycle. The experiments tested the hypothesis that perceptual qualities would be altered when there was an increased likelihood of interactions occurring between the two electrode places. The parameters of the stimulation which were manipulated to test this hypothesis were the time delay between the pulses on the two electrodes (2 ms and a value between 0.62 and 0.92 ms), the distance between the component electrode rings of each bipolar pair (3.75 mm and either 2.25 or 1.5 mm), and the distance between the two bipolar pairs in the dual-electrode stimuli (from 0.75 to 12.0 mm). Five sets of 15 loudness balanced stimuli were created, each set having different stimulation parameters.
These stimuli consisted of five single-electrode stimuli (a 250-Hz pulse train on each of five electrodes) and the ten dual-electrode stimuli formed by the combinations of those five electrodes. Two perceptual dissimilarity matrices were obtained for each subject and each set, and were analyzed using repeated nonmetric multidimensional scaling techniques. The resultant ‘‘stimulus spaces’’ were then examined to see how many perceptual dimensions the stimuli were best described by, and to what perceptual or stimulus qualities the dimensions might correspond. The results showed that the percept evoked by dual-electrode stimulation contained two main dimensions. Increasing the width of the current path to create substantially overlapping stimulation areas, or altering the temporal delay between the two electrodes, had very little effect on this percept. The position of the stimuli in the two-dimensional space was related to the distances of the two component electrodes along the electrode array. These results are relevant to speech processing strategies and electrode design for cochlear implants, as they imply that the creation of discrete, nonoverlapping areas of stimulation may not cause the percepts to be more distinct, and therefore may not necessarily lead to better speech perception.
The effect of distractor frequency on judgments of target laterality based on interaural delays
Authors: Dye Raymond H. , Stellmack Mark A. , Grange Anthony N. , Yost William A. 
Published: October 2005

A two-dimensional stimulus-classification paradigm was used to examine the ability of listeners to judge the laterality of an interaurally delayed low-frequency target component presented concurrently with a distractor component. Of primary interest was the effect on performance of the frequency difference (Δf) between the target and distractor. In one set of conditions, the target was fixed at 753 Hz and the distractor was 353, 553, 653, 703, 803, 853, 953, or 1153 Hz (fixed within a block of trials). In a second set of conditions, the distractor was fixed at 753 Hz and the target frequency was 353, 553, 653, 703, 803, 853, 953, or 1153 Hz. The listeners were presented with a target component with an interaural delay that varied from trial to trial, taking on one of ten values, five leading to the left ear and five leading to the right. A distractor component was simultaneously presented with an interaural delay that also took on one of the same ten values. Delays ranged from −90 to +90 μs in 20-μs steps. During a block of 100 trials, each of the possible combinations of target and distractor delay was presented once and only once in a random order.
Listeners were instructed to make left–right judgments based on the target delay. Each condition was repeated ten times, and the slopes of the best linear boundaries between left and right responses were used to derive the relative weights given to the target and distractor. The duration of the signals was 200 ms. Two of the eight listeners weighted the target heavily when the target and distractor were spectrally remote but gave the two components equal weight when the difference in frequency was small. These two listeners yielded similar target weights regardless of which component was designated as the target. One listener gave nearly equal weight to the target and the distractor regardless of Δf. Five of the listeners gave greater weight to the higher of the two frequencies regardless of which was assigned as the target. This high-frequency dominance is explained in terms of cross-correlation functions based on the composite two-tone waveforms.
Collinear ultrasonic four-wave mixing in suspensions of particles and bubbles.
Authors: Kwiatkowski Christopher S. , Marston Philip L. 
Published: October 2005

The interaction of sound with sound in a suspension can be mediated by the suspension’s response to acoustic radiation pressure [H.J. Simpson and P.L. Marston, J. Acoust. Soc. Am. 98, 1731–1741 (1995)]. Four wave mixing mediated by a suspension with collinear pump and probe waves is investigated. Radiation pressure from counter propagating pump beams induces a periodic grating in the number density of hollow glass microspheres suspended in a water/sugar mixture designed to make the particles neutrally buoyant. The Bragg scattering amplitude was measured using a single PVDF transducer as both the probe source and receiver that is parallel with the standing pump wave nodal planes. Reflection coefficients are calculated by comparing the reflected and transmitted waves. By increasing the particle concentration, total Bragg reflectivities from the established grating reaching 20% have been seen, which is still in the region of agreement between the Born approximation and transfer matrix theory. The dynamics of both the grating formation and dissolution have been studied, leading to the conclusion that grating dissolution is not dominated by diffusion alone. Bragg scattering by gratings of gas bubbles caused by cavitation was detected. [Work supported by the Office of Naval Research.]
All posters will be on display from 1:00 to 5:00 p.m. To allow contributors an opportunity to see other posters, contributors of odd-numbered papers will be at their posters from 1:00 to 3:00 p.m. and contributors of even-numbered papers will be at their posters from 3:00 to 5:00 p.m.
Wave field visualization as an interpretational tool in borehole geophysics.
Authors: Rao V. N. Rama , Schmidt Henrik , Vandiver Kim 
Published: October 2005

A hybrid model for computing the radiation from a borehole while drilling has been developed. A model for modal propagation in a radially layered borehole is coupled with the OASES code for full wave modeling of the resultant seismic wave field. The coupling is performed using the concept of effective sources. First, an equivalent seismic source array that produces the same far-field radiation as the borehole is determined. This source array is then introduced into the layered earth model and the resulting seismic field is computed. Three propagating modes exist in the borehole in the presence of the drill-pipe. The individual modes radiate into the formation in a pattern that is dependent on geophysical properties, with the resulting radiation pattern being extremely complex and difficult to interpret physically. Here, visualization and animation in particular has proven to be an extremely useful tool. For example, animation allows the direct identification of the complex arrival pattern recorded on surface mounted geophones. The fundamental differences between the radiation patterns in fast and slow formations are also clearly demonstrated using computer visualization and animation.
Standards Committee S12 on Noise. Working group chairs will report on their progress for the production of noise standards. The interaction with ISO/TC 43/SC1 and ISO/TC 94/SC12 activities will also be discussed, with reference to the international standards under preparation. A report will be given on the meeting of ISO/TC 43/SC1 in Pretoria, South Africa, held in February 1996. The Chairs of the respective U.S. Technical Advisory Groups (H. E. von Gierke and E. H. Berger) will report on current activities of these international Technical Subcommittees under ISO. Scope of S12. Standards, specifications and terminology in the field of acoustical noise pertaining to methods of measurement, evaluation, and control; including biological safety, tolerance and comfort and physical acoustics as related to environmental and occupational noise.
RUS investigation of the anisotropic elastic properties of GFRP composites at low temperatures.
Authors: Whitney Timothy M. , Green Robert E. 
Published: October 2005

The resonance spectrum of any specimen is dependent on its symmetry, density, geometry, elastic properties, and the boundary conditions. By using specimens with simple known geometry and models including speci- men symmetry, resonance ultrasound spectrosopy can determine the full elastic stiffness tensor to great precision with one measurement. This measurement is fast, taking less than a minute with state-of-the-art instrumentation, making it appropriate for measuring properties as a function of temperature. Parts per million changes in specimen density, geometry, elastic moduli, temperature, and boundary conditions can be detected in carbon fiber reinforced epoxy composite materials with resonance ultrasound spectroscopy. It is important to know the mechanical properties of carbon fiber reinforced epoxy composite materials at low temperatures for underwater, space, and polar applications. The amplitude/frequency resonance spectra of four different lay-ups of AS4/3501-6 carbon fiber reinforced epoxy composite have been measured at 1 °C intervals from −177 °C to 25 °C. The spectra indicate increasing stiffness and decreasing damping with decreasing temperature.
All posters will be on display from 1:00 to 4:00 p.m. To allow contributors an opportunity to see other posters, contributors of odd-numbered papers will be at their posters from 1:00 to 2:30 p.m. and contributors of even-numbered papers will be at their posters from 2:30 to 4:00 p.m.
Rayleigh scattering from nonspherical particles
Authors: Palmer D. R. 
Published: October 2005

A comprehensive framework is developed for calculating the intensity received by a monostatic sonar system due to backscattering from a cloud of nonspherical particles suspended in the ocean. The cloud can consist of different types of particles having arbitrary shapes, volume distributions, and orientations, as well as an overall mass density that varies spatially within the cloud. In the Rayleigh region it is possible to average over particle orientation exactly. The averaged backscattered intensity depends on particle shape through the eigenvalues of a tensor that can, in principle, be determined by solving a boundary value problem for a harmonic function. Since the solution to this boundary value problem is out of reach practically, bounds are obtained on the eigenvalues using the theory of isoperimetric inequalities. Bounds can thereby be obtained on the backscattered intensity that are independent of particle shape. These bounds form the basis for obtaining estimates of the error that is made by assuming the particles in the cloud scatter sound as if they were spherical. A number of examples and applications are considered, the most important of which is the feasibility of a sonar to image black smoker hydrothermal plumes. The reassuring result that the spherical particle assumption is likely to lead to feasibility criteria that underestimate the performance of a sonar is obtained.
The isoperimetric bounds are combined with the principle of maximum entropy, applied to the distribution of particle shapes, to obtain a new expression for the square of the amplitude for backscattering at wave number k0 from a particle of volume V, specific bulk modulus e and specific density h: Φ2=(k20V/4π)2[(e−1)/e+(h2−1)/2h]2. This amplitude is obtained by averaging over particle orientation and particle shape and is to be compared to the corresponding quantity for a sphere Φ2sp=(k20V/4π)2[(e−1)/e +(3(h−1))/(2h+1)]2. The use of the new expression is preferred in situations where it is known the particle shapes are quite variable and irregular and where 1.0≤h≤2.5. In all the examples considered it is found the error that results from assuming the particles scatter sound as if they were spherical is small. This is comforting and consistent with one’s intuition that in the Rayleigh region the scattered sound should be somewhat insensitive to the shape of the scatterer.
The effect of sea-surface roughness on shallow water waveguide propagation: A coherent approach
Authors: Norton Guy V. , Novarini Jorge C. 
Published: October 2005

Standard propagation models in underwater acoustics (e.g., normal modes, PE) are deterministic in nature, i.e., they deal with a single realization of the environment. Additionally, for mathematical reasons, they typically treat the sea surface as a flat pressure-release surface. Effects of sea surface and bottom roughness are incorporated through a loss mechanism. This is accomplished by including an additional attenuation factor based on coherent loss of the surface-interacting component of the propagating field. This type of correction presents a mathematically inconsistent model, since usually results from stochastic scattering models are applied to results from single realizations of the stochastic medium. Moreover, scattering kernels are generally derived assuming a homogeneous medium underlying the sea surface, an assumption incompatible with a realistic environment. Using a numerical model [Norton et al., J. Acoust. Soc. Am. 97, 2173–2180 (1995)] that combines a high fidelity Parabolic Equation propagation model with the conformal mapping technique developed by Dozier [L. B. Dozier, J. Acoust. Soc. Am. 75, 1415–1432 (1984)] to handle surface roughness in a marching algorithm, forward propagation with a single realization of a rough sea surface overlying a complex ocean environment can be modeled in a mathematically consistent way.
This technique is applied to the problem of shallow water propagation with a rough sea surface. For the adopted environment and range of rms roughnesses considered (0.28&lt;kh&lt;2.33, where k is the acoustic wave number and h is the rms surface height) the inclusion of the rough surface introduces a significant increase in the transmission loss and vertical-angle distribution of the propagating field. Results for this environment also show that, on average, the transmission loss is close to that calculated using the roughness-induced attenuation factor approximation. The transmission loss calculated with the roughness-induced attenuation factor exhibits a smoother range dependence, indicating strong attenuation of energy at steeper propagating angles. However, when strong upward refraction conditions exist, coherent effects and energy redistribution cannot be ignored and results from the procedure which incorporates the roughness through a loss mechanism are in error.