bluuebunny/crossref_metadata_2025 huggingface dataset:
Proteomics of semen and its constituents
Authors: Duncan Mark W. , Thompson Heather S.
Published: July 2007

Semen is a complex fluid comprising sperm and other products of the testes together with secretions from the accessory sex glands including the prostate, seminal vesicles, and the bulbourethral gland. Studies of the protein components of seminal fluid, with or without the sperm present, can improve our understanding of reproductive biology; have potential clinical applications in the assessment and treatment of infertility; can assist with the diagnosis and management of urological diseases; and, at times, can offer important forensic insights. This review examines the application of proteomic methods to the study of spermatozoa and seminal fluid and highlights some of the unique challenges associated with the collection, fractionation, and analysis of this fluid. The discussion is restricted to issues relating to human semen, although we make occasional reference to important studies from animals.
Crystallization study of amorphous Pd43Ni10Cu27P20 alloy by internal friction measurement
Authors: Yang K. W. , Jia E. G. , Shui J. P. , Zhu Z. G.
Published: July 2007

We have successfully measured the internal friction and electrical resistivity of Pd43Ni10Cu27P20 bulk metallic glass during a constant heating process. The results of electrical resistivity suggest that the position of the internal friction peak is the onset temperature of crystallization. The dependence of internal friction on frequencies show both linear and nonlinear relations. The internal friction at 623 K in the supercooled liquid region decreases monotonously with the increase of annealing time, indicating structural relaxation and subsequent crystallization occurs during isothermal annealing near the crystallization temperature. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
On (ε,k)‐min‐wise independent permutations
Authors: Alon Noga , Itoh Toshiya , Nagatani Tatsuya
Published: July 2007

A family of permutations of
$\cal{F}$ [n] = {1,2,…,n} is (ε,k)‐min‐wise independent if for every nonempty subset X of at most k elements of [n], and for any x ∈ X, the probability that in a random element π of $\cal{F}$, π(x) is the minimum element of π(X), deviates from 1/∣X∣ by at most ε/∣X∣. This notion can be defined for the uniform case, when the elements of $\cal{F}$ are picked according to a uniform distribution, or for the more general, biased case, in which the elements of $\cal{F}$ are chosen according to a given distribution D. It is known that this notion is a useful tool for indexing replicated documents on the web.

We show that even in the more general, biased case, for all admissible k and ε and all large n, the size of $\cal{F}$ must satisfy

as well as

This improves the best known previous estimates even for the uniform case. © 2007 Wiley Periodicals, Inc. Random Struct. Alg., 2007
Clinical effects and outcome of feline permethrin spot-on poisonings reported to the Veterinary Poisons Information Service (VPIS), London
Authors: Sutton Nicholas M , Bates Nicola , Campbell Alexander
Published: July 2007

Permethrin is a pyrethroid insecticide used in dermally applied spot-on flea treatments for dogs. Permethrin-based spot-on preparations are contraindicated in cats because of the high risk of toxicosis. The Veterinary Poisons Information Service (VPIS) is a 24-h access telephone service that provides veterinary professionals in the United Kingdom with information on the management of poisoned animals. In a review of 286 cases reported to the VPIS regarding inappropriate feline exposure to permethrin spot-on (PSO) preparations, 96.9% were symptomatic. Increased muscular activity (as evidenced by twitching, tremor, muscle fasciculations or convulsions) was common and occurred in 87.8% of cases. The duration of increased muscle activity was long, with convulsions lasting on average 38.9 h and tremors 32 h. Recovery typically occurred within 2 to 3 days but in some cases took 5 to 7 days. Death occurred in 10.5% of cases.
Host specificity ofArgulus coregoni(Crustacea: Branchiura) increases at maturation
Authors: MIKHEEV V. N. , PASTERNAK A. F. , VALTONEN E. T.
Published: July 2007

We tested the hypothesis that host specificity in ectoparasites does not depend exclusively on the features of the host but also on surrounding habitats, using 2 fish ectoparasites,Argulus coregoniandA. foliaceus(Crustacea: Branchiura), occurring sympatrically in Finnish lakes. Although these parasites are considered to be of low specificity, we found that the larger of the 2 species,A. coregonideveloped a pronounced preference for salmonid hosts at the beginning of maturation (defined by the presence of copulating specimens).Argulus foliaceusinfects a much wider range of fish hosts. We showed that specialization ofA. coregonion salmonids does not necessarily result from incompatibility with other fishes, but could instead reflect higher sensitivity of oxygen depletion compared withA. foliaceus. AdultA. coregonimay meet these demands by attaching to salmonids, the typical inhabitants of well-aerated waters. Young parasites of both species showed little host specificity and attached mainly to fishes with higher body reflectivity. In host choice experiments,A. coregoniof 4–5 mm length preferred salmonids (rainbow trout) to cyprinids (roach) irrespective of the type of fish host, on which it had been previously grown in the laboratory. We suggest that such an innate ontogenetic shift in host preference maintains the major part of the parasite population on its principal host, ensuring successful reproduction within suitable habitats.
Paradigm misplaced? Antarctic marine ecosystems are affected by climate change as well as biological processes and harvesting
Authors: Nicol Stephen , Croxall John , Trathan Phil , Gales Nick , Murphy Eugene
Published: July 2007

A recent review by Ainley et al. has suggested that recent investigations of the ecological structure and processes of the Southern Ocean have “almost exclusively taken a bottom-up, forcing-by-physical-processes approach relating individual species' population trends to climate change”. We examine this suggestion and conclude that, in fact, there has been considerable research effort into ecosystem interactions over the last 25 years, particularly through research associated with management of the living resources of the Southern Ocean. Future Southern Ocean research will make progress only when integrated studies are planned around well structured hypotheses that incorporate both the physical and biological drivers of ecosystem processes.
Short Note: Observations of top predators foraging on fish in the pack ice of the southern Ross Sea
Authors: Lauriano Giancarlo , Vacchi Marino , Ainley David , Ballard Grant
Published: July 2007

New micro-technology with links to satellites has revolutionized the collection of information on the foraging movements of marine animals, but observations of actual foraging are still very rare. Here we describe foraging by killer whales (Orcinus orca(L.)), minke whales (Balaenoptera bonaerensisBurmeister), Adélie penguins (Pygoscelis adeliae(Hombron & Jacquinot)) and emperor penguins (Aptenodytes forsteriGray), in all cases we believe feeding on fish, in the south-western Ross Sea, Antarctica.
A multidomain decomposition method to solve electromagnetic scattering problems in time domain
Authors: Mouysset V. , Mazet P. A. , Borderies P.
Published: July 2007

This paper is devoted to the numerical treatment wide electromagnetic scattering scenes by a decomposition into disjointed subdomains to solve time domain Maxwell's equations. It presents a way to adapt existing time volumic scheme in order to simulate interactions between multiple sources and/or scatterers when either computational costs or the accumulation of numerical errors become prohibitive because of important volumes of free‐space meshes. This is done by an automatic implementation of the proposed method which leads to a parallel algorithm with an adaptive criterion on the accuracy, introducing by the way some very significant gains on the computational effort. Numerical studies are performed to show the efficiency of this method in comparison with mono‐domain resolutions. Improvements of the approximations, relevant of the introduction of the adaptive parameter, are also quantified and then demonstrate their benefits with respect to a straightforward multidomain scheme involving integral formulas.
Rate of decrease of the specific surface area of dry snow: Isothermal and temperature gradient conditions
Authors: Taillandier Anne‐Sophie , Domine Florent , Simpson William R. , Sturm Matthew , Douglas Thomas A.
Published: July 2007

The specific surface area (SSA) of snow is the surface area available to gases per unit mass. It is an important variable for quantifying air‐snow exchange of chemical species, and it is closely related to other variables such as albedo. Snow SSA decreases during metamorphism, but few data are available to quantify its rate of decrease. We have performed laboratory experiments under isothermal and temperature gradient conditions during which the SSA of snow samples was monitored for several months. We have also monitored the SSA of snowfalls subjected to large temperature gradients at a field site in the central Alaskan taiga. The same snow layers were also monitored in a manipulated snowpack where the temperature gradient was greatly reduced. In all cases, the SSA decay follows a logarithmic equation with three adjustable variables that are parameterized using the initial snow SSA and the time‐averaged temperature of the snow. Two parameterizations of the three adjustable variables are found: One applies to the isothermal experiments and to the quasi‐isothermal cases studied in Alaska (equitemperature (ET) metamorphism), and the other is applicable to both the laboratory experiments performed under temperature gradients and to the natural snowpack in Alaska (temperature gradient (TG) metamorphism). Higher temperatures accelerate the decrease in SSA, and this decrease is faster under TG than ET conditions. We discuss the conditions of applicability of these parameterizations and use them to speculate on the effect of climate change on snow SSA. Depending on the climate regime, changes in the rate of decay of snow SSA and hence in snow albedo may produce either negative or positive feedbacks on climate change.
Ice sheet grounding line dynamics: Steady states, stability, and hysteresis
Authors: Schoof Christian
Published: July 2007

The ice sheet–ice shelf transition zone plays an important role in controlling marine ice sheet dynamics, as it determines the rate at which ice flows out of the grounded part of the ice sheet. Together with accumulation, this outflow is the main control on the mass balance of the grounded sheet. In this paper, we verify the results of a boundary layer theory for ice flux in the transition zone against numerical solutions that are able to resolve the transition zone. Very close agreement is obtained, and grid refinement in the transition zone is identified as a critical component in obtaining reliable numerical results. The boundary layer theory confirms that ice flux through the grounding line in a two‐dimensional sheet‐shelf system increases sharply with ice thickness at the grounding line. This result is then applied to the large‐scale dynamics of a marine ice sheet. Our principal results are that (1) marine ice sheets do not exhibit neutral equilibrium but have well‐defined, discrete equilibrium profiles; (2) steady grounding lines cannot be stable on reverse bed slopes; and (3) marine ice sheets with overdeepened beds can undergo hysteresis under variations in sea level, accumulation rate, basal slipperiness, and ice viscosity. This hysteretic behavior can in principle explain the retreat of the West Antarctic ice sheet following the Last Glacial Maximum and may play a role in the dynamics of Heinrich events.
Estimating resilience for water resources systems
Authors: Li Yi , Lence Barbara J.
Published: July 2007

Resilience characterizes the recovery capacity of repairable systems from the failure state to the safe state. Resilience has been recognized as a meaningful probabilistic indicator for evaluating risk‐cost trade‐offs in water resources systems. Traditionally, the resilience in the discrete time domain is estimated by sampling methods, which have a high computational expense. No single approximation approach has been well developed for estimating resilience, even under stationary conditions. This paper proposes two practical approximation methods for estimating the lag‐1 resilience in the discrete time domain. Both methods are theoretical developments, one based on a bivariate normal distribution, and the other based on a stochastic linear prediction of the performance function using the mean point of the failure domain. The foundations of both methods are the first‐order reliability method and the periodic vector autoregressive moving‐average time series model. The methods are robust for a wide range of problem characteristics and are applicable for systems facing stationary or nonstationary input conditions.
Lagrangian hydrocode simulations of the 1958 Lituya Bay tsunamigenic rockslide
Authors: Schwaiger H. F. , Higman B.
Published: July 2007

The interaction of debris flows, whether subaqueous or subaerial, with bodies of water can produce tsunamis with a locally devastating impact. When debris flows begin above the water surface, the impact can produce a large air cavity, corresponding to a large effective volume of water displaced and complicating efforts to model the resulting tsunami. Because grid‐based, Eulerian numerical methods have an inherent difficulty tracking material boundaries, we have implemented a particle‐based, Lagrangian model (Smoothed Particle Hydrodynamics). We treat the debris flow as an incompressible, viscous fluid and the body of water as inviscid. We use this model to simulate the 1958 Lituya Bay rockslide and resulting tsunami. Our simulation results compare favorably with field observations as well as a scaled laboratory experiment and numerical studies.
Dependence of cyclotron maser instability growth rates on electron velocity distributions and perturbation by solitary waves
Authors: Mutel R. L. , Peterson W. M. , Jaeger T. R. , Scudder J. D.
Published: July 2007

We calculate growth rates and corresponding gains for right‐hand circularly polarized extraordinary (RX) and left‐hand ordinary circularly polarized (LO) mode radiation associated with the cyclotron maser instability (CMI) for parameterized horseshoe electron velocity distributions. The velocity distribution function was modeled to closely fit the electron distribution functions observed in the auroral cavity. We systematically varied the model parameters as well as the propagation direction to study the dependence of growth rates on model parameters. The growth rate depends strongly on loss cone opening angle, which must be less than 90° for significant CMI growth. The growth rate is sharply peaked for perpendicular radiation (k∥ = 0), with a full width at half maximum 1.7°, in good agreement with observed k‐vector orientations and numerical simulations. The fractional bandwidth varied between 10−4 and 10−2, depending most strongly on propagation direction. This range encompasses nearly all observed fractional auroral kilometric radiation (AKR) burst bandwidths. We find excellent agreement between the computed RX mode emergent intensities and observed AKR intensities assuming convective growth length Lc ≈ 20–40 km and group speed 0.15c. The only computed LO mode growth rates compatible observed LO mode radiation levels occurred for number densities more than 100 times the average energetic electron densities measured in auroral cavities. This implies that LO mode radiation is not produced directly by the CMI mechanism but more likely results from mode conversion of RX mode radiation. We find that perturbation of the model velocity distribution by large ion solitary waves (ion holes) can enhance the growth rate by a factor of 2–4. This will result in a gain enhancement more than 40 dB depending on the convective growth length within the structure. Similar enhancements may be caused by strong electromagnetic ion cyclotron waves.
Last global extinction in the deep sea during the mid‐Pleistocene climate transition
Authors: Hayward Bruce W. , Kawagata Shungo , Grenfell Hugh R. , Sabaa Ashwaq T. , O'Neill Tanya
Published: July 2007

Twenty percent (19 genera, 95 species) of cosmopolitan, deep‐sea (500–4000 m), benthic foraminiferal species became extinct during the late Pliocene–Middle Pleistocene (3–0.12 Ma), with the peak of extinctions (76 species) occurring during the mid‐Pleistocene Climate Transition (MPT, 1.2–0.55 Ma). One whole family (Stilostomellidae, 30 species) was wiped out, and a second (Pleurostomellidae, 29 species) was decimated with just one species possibly surviving through to the present. Our studies at 21 deep‐sea core sites show widespread pulsed declines in abundance and diversity of the extinction group species during more extreme glacials, with partial interglacial recoveries. These declines started in the late Pliocene in southern sourced deep water masses (Antarctic Bottom Water, Circumpolar Deep Water) and extending into intermediate waters (Antarctic Intermediate Water, North Atlantic Deep Water) in the MPT, with the youngest declines in sites farthest downstream from high‐latitude source areas for intermediate waters. We infer that the unusual apertural types that were targeted by this extinction period were adaptations for a specific kind of food source and that it was probably the demise of this microbial food that resulted in the foraminiferal extinctions. We hypothesize that it may have been increased cold and oxygenation of the southern sourced deep water masses that impacted on this deep water microbial food source during major late Pliocene and Early Pleistocene glacials when Antarctic ice was substantially expanded. The food source in intermediate water was not impacted until major glacials in the MPT when there were significant expansion of polar sea ice in both hemispheres and major changes in the source areas, temperature, and oxygenation of global intermediate waters.
Spatial and Lorentzian surfaces in Robertson-Walker space times
Authors: Chen Bang-Yen , Van der Veken Joeri
Published: July 2007

Let L14(f,c)=(I×fS,gfc) be a Robertson-Walker space time which does not contain any open subset of constant curvature. In this paper, we provide a general study of nondegenerate surfaces in L14(f,c). First, we prove the nonexistence of marginally trapped surfaces with positive relative nullity. Then, we classify totally geodesic submanifolds. Finally, we classify the family of surfaces with parallel second fundamental form and the family of totally umbilical surfaces with parallel mean curvature vector.
Polytropic gas dynamics revisited
Authors: Chen Yu-Tung , Lee Niann-Chern , Tu Ming-Hsien
Published: July 2007

We investigate the Hamiltonian as well as Lax formulations of the polytropic gas dynamics which can be characterized by the polytropic exponent γ=1+h. We show that when h=1∕m with ∣m∣∊N⩾2, the resonant phenomena occur in bi-Hamiltonian formulation and logarithmic-type conserved charges emerge naturally. We provide a logarithmic Lax representation for conserved charges and the whole hierarchy flows, which coincides with the bi-Hamiltonian formulation constructed from a two-dimensional Frobenius manifold associated with the polytropic gas dynamics.
Three-dimensional oscillatory long-wave Marangoni convection in a binary liquid layer with the Soret effect: Bifurcation analysis
Authors: Shklyaev S. , Nepomnyashchy A. A. , Oron A.
Published: July 2007

Three-dimensional long-wave oscillatory Marangoni convection in a thin layer of binary mixture with a nondeformable interface is investigated in the presence of the Soret effect. Both thermocapillary and solutocapillary effects are taken into account. A set of amplitude equations is obtained and studied analytically near the critical value of the Marangoni number. It is shown that alternating rolls (either rhombic or square) are selected and they bifurcate supercritically. Subcritical bifurcation takes place only for alternating rolls on a square lattice in a narrow range of parameters.
Quantum effects on polarization transport scatterings in partially ionized dense hydrogen plasmas
Authors: Kim Hwa-Min , Jung Young-Dae
Published: July 2007

The quantum effects on the polarization momentum transport scatterings are investigated in partially ionized dense hydrogen plasmas. The partial wave analysis is applied to represent the electron-atom polarization momentum transport cross section as a function of the de Broglie wavelength, Debye length, collision energy, and quantum states. The energy dependence of the scattering phase shift is found to be important for the small de Broglie wavelength domain. It is important to note that the quantum effects increase the polarization momentum transport cross section.
Laser beam quality and pointing measurement with an optical resonator
Authors: Kwee Patrick , Seifert Frank , Willke Benno , Danzmann Karsten
Published: July 2007

We present a compact diagnostic breadboard that is based on an optical ring resonator for measuring beam quality and pointing of single-frequency continuous wave lasers at a wavelength of 1064nm. To determine the beam quality of the coherent test beam, this optical resonator is used to perform a mode decomposition into Hermite-Gaussian modes. For our laser system, a power fraction in the fundamental Gaussian mode of 97.2%±0.2% was measured. Residual misalignment and mis-mode-matching to the resonator as well as the astigmatism and/or ellipticity of the test beam have been determined. Numerical simulations showed that measurements of the M2 factor and transversal intensity distribution are not suitable for determining this power fraction. To measure the beam pointing, the fundamental mode of the optical resonator was used as a stable reference. The pointing of the test beam was measured with the differential wave front sensing technique up to Fourier frequencies of 1kHz with a sensitivity to relative pointing of ∣ϵ∣=1×10−6∕Hz. Pointing measurements with an alternative method were performed and showed good agreement.
A monopole near a black hole
Authors: Bunster Claudio , Henneaux Marc
Published: July 2007

A striking property of an electric charge near a magnetic pole is that the system possesses angular momentum even when both the electric and the magnetic charges are at rest. The angular momentum is proportional to the product of the charges and independent of their distance. We analyze the effect of bringing gravitation into this remarkable system. To this end, we study an electric charge held at rest outside a magnetically charged black hole. We find that even if the electric charge is treated as a perturbation on a spherically symmetric magnetic Reissner–Nordstrom hole, the geometry at large distances is that of a magnetic Kerr–Newman black hole. When the charge approaches the horizon and crosses it, the exterior geometry becomes that of a Kerr–Newman hole, with electric and magnetic charges and with total angular momentum given by the standard value for a charged monopole pair. Thus, in accordance with the “no-hair theorem,” once the charge is captured by the black hole, the angular momentum associated with the charge monopole system loses all traces of its exotic origin and is perceived from the outside as common rotation. It is argued that a similar analysis performed on Taub–NUT space should give the same result.
Genome-wide patterns of single-feature polymorphism in
Arabidopsis thaliana
Authors: Borevitz Justin O. , Hazen Samuel P. , Michael Todd P. , Morris Geoffrey P. , Baxter Ivan R. , Hu Tina T. , Chen Huaming , Werner Jonathan D. , Nordborg Magnus , Salt David E. , Kay Steve A. , Chory Joanne , Weigel Detlef , Jones Jonathan D. G. , Ecker Joseph R.
Published: July 2007

We used hybridization to the ATH1 gene expression array to interrogate genomic DNA diversity in 23 wild strains (accessions) of
Arabidopsis thaliana
(arabidopsis), in comparison with the reference strain Columbia (Col). At <1% false discovery rate, we detected 77,420 single-feature polymorphisms (SFPs) with distinct patterns of variation across the genome. Total and pair-wise diversity was higher near the centromeres and the heterochromatic knob region, but overall diversity was positively correlated with recombination rate (
R
2
= 3.1%). The difference between total and pair-wise SFP diversity is a relative measure contrasting diversifying or frequency-dependent selection, similar to Tajima's D, and can be calibrated by the empirical genome-wide distribution. Each unique locus, centered on a gene, has a diversity and selection score that suggest a relative role in past evolutionary processes. Homologs of disease resistance (
R
) genes include members with especially high levels of diversity often showing frequency-dependent selection and occasionally evidence of a past selective sweep. Receptor-like and S-locus proteins also contained members with elevated levels of diversity and signatures of selection, whereas other gene families, bHLH, F-box, and RING finger proteins, showed more typical levels of diversity. SFPs identified with the gene expression array also provide an empirical hybridization polymorphism background for studies of gene expression polymorphism and are available through the genome browser
http://signal.salk.edu/cgi-bin/AtSFP
.
[
64
Cu-NOTA-8-Aoc-BBN(7-14)NH
2
] targeting vector for positron-emission tomography imaging of gastrin-releasing peptide receptor-expressing tissues
Authors: Prasanphanich Adam F. , Nanda Prasant K. , Rold Tammy L. , Ma Lixin , Lewis Michael R. , Garrison Jered C. , Hoffman Timothy J. , Sieckman Gary L. , Figueroa Said D. , Smith Charles J.
Published: July 2007

Radiolabeled peptides hold promise as diagnostic/therapeutic targeting vectors for specific human cancers. We report the design and development of a targeting vector, [
64
Cu-NOTA-8-Aoc-BBN(7-14)NH
2
] (NOTA = 1,4,7-triazacyclononane-1,4,7-triacetic acid, 8-Aoc = 8-aminooctanoic acid, and BBN = bombesin), having very high selectivity and affinity for the gastrin-releasing peptide receptor (GRPr). GRPrs are expressed on a variety of human cancers, including breast, lung, pancreatic, and prostate, making this a viable approach toward site-directed localization or therapy of these human diseases. In this study, [NOTA-X-BBN(7-14)NH
2
] conjugates were synthesized, where X = a specific pharmacokinetic modifier. The IC
50
of [NOTA-8-Aoc-BBN(7-14)NH
2
] was determined by a competitive displacement cell-binding assay in PC-3 human prostate cancer cells using
125
I-[Tyr
4
]-BBN as the displacement ligand. An IC
50
of 3.1 ± 0.5 nM was obtained, demonstrating high binding affinity of [NOTA-8-Aoc-BBN] for the GRPr. [
64
Cu-NOTA-X-BBN] conjugates were prepared by the reaction of
64
CuCl
2
with peptides in buffered aqueous solution.
In vivo
studies of [
64
Cu-NOTA-8-Aoc-BBN(7-14)NH
2
] in tumor-bearing PC-3 mouse models indicated very high affinity of conjugate for the GRPr. Uptake of conjugate in tumor was 3.58 ± 0.70% injected dose (ID) per g at 1 h postintravenous injection (p.i.). Minimal accumulation of radioactivity in liver tissue (1.58 ± 0.40% ID per g, 1 h p.i.) is indicative of rapid renal-urinary excretion and suggests very high
in vivo
kinetic stability of [
64
Cu-NOTA-8-Aoc-BBN(7-14)NH
2
] with little or no
in vivo
dissociation of
64
Cu
2+
from the NOTA chelator. Kidney accumulation at 1 h p.i. was 3.79 ± 1.09% ID per g. Molecular imaging studies in GRPr-expressing tumor models produced high-contrast, high-quality micro-positron-emission tomography images.
Synthesis and characterization of methylsalicylate and acetaminophen silyl ether canditates for prodrugs
Authors: Assadi M.G. , Golipour N.
Published: July 2007

Some silyl ethers of acetaminophen and methylsalicylate of general formula ArOSiRR′R″ ArOH = parahydroxyacetanilide or 2-hydroxybenzoic acid methyl ester; SiRR′R″ = trimethylsilyl, triethylsilyl, dimethyltert(Bu)silyl, triphenylsilyl, dimethylsilyl, tris(trimethylsilyl)silyl (sisyl) or dimethylvinylsilyl have been prepared and fully characterized. The compounds were prepared from the combination of either acetaminophen or methylsalicylate with the silyl chloride of these groups. Two methods were employed. In the first Et3N was used in THF to remove HCl in coupling the silyl group to the organic substrate. In the other method imidazole as a base in dimethylformamide (DMF) were used. The effect of the silyl groups in providing stability to the compounds preventing or enhancing hydrolysis of the silicon-containing group was determined. The compounds were characterized by: NMR, IR, mass spectroscopy and elemental analysis (CHN) methods.
Crystal structure and vibrational analyses of nonlinear optical L-histidinium trifluoroacetate single crystals
Authors: Mathivanan V. , Gokul Raj S. , Ramesh Kumar G. , Raghavalu T. , Mohan R. , Suriya Kumar K. , Kovendhan M. , Varghese B.
Published: July 2007

L-histidinium trifluoroacetate {LHTFA; [(C3N2H4) CH2CH (NH3) (CO2)]+ CF3COO−}, single crystals were grown by slow evaporation of an aqueous solution at room temperature. It crystallizes in a noncentrosymmetric space group of P1 of the triclinic system, with a = 5.1724(6) Å, b = 8.8183(12) Å, c = 12.481(3) Å, α = 96.193(17)°, β = 99.853(13)°, γ = 102.106(13)° and V = 542.26(16) Å3. The structure was solved from 2063 unique reflections with a final residue factor ‘R’ of 0.038. There are two histidine cations and two trifluoroacetate anions in the asymmetric unit. The protonated cations and deprotonated anions are linked by a number of intermolecular N–H ... O hydrogen bonds to form a three-dimensional network. The relative powder second harmonic generation (SHG) efficiency has been evaluated and found as deff = 0.84 deff (KDP).
Congenital Cholesteatoma of the Mastoid Temporal Bone
Authors: Warren Frank M. , Bennett Marc L. , Wiggins Richard H. , Saltzman Karen L. , Blevins Katherine S. , Shelton Clough , Harnsberger H Ric
Published: July 2007

Objective: Congenital mastoid cholesteatomas are rare lesions of the temporal bone. The clinical presentation of these lesions is variable, making them difficult to identify preoperatively. We evaluated our series of mastoid congenital cholesteatomas (CCs) in an effort to better define the clinical presentation, imaging characteristics, and surgical challenges specific to this lesion.

Study Design: Retrospective chart and radiologic study review.

Methods: The medical records of patients with the diagnosis of mastoid CC on radiologic imaging over a 15‐year period were reviewed. All had surgical and pathologic confirmation. Eight patients underwent preoperative computed tomography (CT). Six also underwent magnetic resonance (MR) scanning. Demographic information, clinical presentation, imaging results, and operative findings were recorded.

Results: Nine patients with the diagnosis of mastoid CC satisfying the inclusion criteria were found. Clinical findings were variable, with the most common presentation being an incidental finding. Imaging findings were more uniform. All CT scans demonstrated an expansile, well‐circumscribed mass centered within the mastoid portion of the temporal bone. All MR scans showed a well‐circumscribed mass with high intensity on T2‐weighted images with precontrasted T1 sequences showing the lesion to be isointense or slightly hyperintense to cerebrospinal fluid (CSF). Operative findings included lateral mastoid cortex erosion, sigmoid sinus exposure, ossicular destruction, facial nerve exposure, and associated postauricular abscess. Management of these lesions is reviewed.

Conclusion: Congenital mastoid cholesteatomas have a variable and nonspecific clinical presentation. Surgical challenges arise from the indolent nature of this clinical entity, which belies the extent of otologic involvement. Imaging with CT and magnetic resonance imaging are diagnostic, defines the extent of these lesions, and facilitates preoperative surgical planning.
Inositol Hexaphosphate and Paclitaxel: Symbiotic Treatment of Oral Cavity Squamous Cell Carcinoma
Authors: Janus Seth C. , Weurtz Beverly , Ondrey Frank G.
Published: July 2007

Objectives/Hypothesis: Nuclear factor (NF)‐κB is an early response gene that has been associated with head and neck squamous cell cancer (HNSCC) progression. NF‐κB activation is induced by some chemotherapy agents, including paclitaxel. The activation of this gene can be correlated with apoptosis resistance. Inositol hexaphosphate (IP6) is a naturally occurring polyphosphorylated carbohydrate. NF‐κB levels were evaluated in oral cavity HNSCC lines after treatment with paclitaxel and IP6, alone and in combination. Resulting levels of cell death and apoptosis were assessed, and conclusions are drawn regarding a possible synergistic relationship between paclitaxel and IP6.

Methods: NF‐κB activation in cancer cells treated with paclitaxel and IP6, alone and in combination, was measured by transient transfection, and results were interpreted by luminometry. Cell proliferation of treated cells was measured by MTT assay. Cell viability and apoptosis of cancer cells treated with paclitaxel and IP6 combinations were quantitated by trypan blue staining and Caspase‐Glo 3/7 assay, respectively.

Results: IP6 was observed to significantly downregulate NF‐κB activation in both NA and CA‐9‐22 oral cavity HNSCC cell lines. Paclitaxel treatments caused increased NF‐κB activation in the same cell lines. IP6 was observed to mitigate paclitaxel‐induced NF‐κB activation in the CA‐9‐22 cell line. IP6, when combined with paclitaxel, reduces CA‐9‐22 cell proliferation, increases cell death, and increases apoptosis, when compared with treatment with paclitaxel alone.

Conclusions: IP6 reduces paclitaxel induced NF‐κB activation and increases paclitaxel‐mediated cell killing and apoptosis. As a well‐tolerated and safe supplement, IP6 deserves further study in the treatment of oral cavity squamous cell carcinoma.
Clinical Use and Material Wear of Polymeric Tracheostomy Tubes
Authors: Björling Gunilla , Axelsson Sara , Johansson Unn‐Britt , Lysdahl Michael , Markström Agneta , Schedin Ulla , Aune Ragnhild E. , Frostell Claes , Karlsson Sigbritt
Published: July 2007

Objectives: The objectives were to compare the duration of use of polymeric tracheostomy tubes, i.e., silicone (Si), polyvinyl chloride (PVC), and polyurethane (PU), and to determine whether surface changes in the materials could be observed after 30 days of patient use.

Methods: Data were collected from patient and technical records for all tracheostomized patients attending the National Respiratory Center in Sweden. In the surface study, 19 patients with long‐term tracheostomy were included: six with Bivona TTS Si tubes, eight with Shiley PVC tubes, and five with Trachoe Twist PU tubes. All tubes were exposed in the trachea for 30 days before being analyzed by scanning electron microscopy (SEM) and attenuated total reflectance Fourier transform infrared spectroscopy (ATR‐FTIR). New tubes and tubes exposed in phosphate‐buffered saline were used as reference.

Results: Si tubes are used for longer periods of time than those made of PVC (P < .0001) and PU (P = .021). In general, all polymeric tubes were used longer than the recommended 30‐day period. Eighteen of the 19 tubes exposed in patients demonstrated, in one or more areas of the tube, evident surface changes. The morphologic changes identified by SEM correlate well with the results obtained by ATR‐FTIR.

Conclusions: Si tracheostomy tubes are in general used longer than those made of PVC and PU. Most of the tubes exposed in the trachea for 30 days suffered evident surface changes, with degradation of the polymeric chains as a result.
Enhanced Survival of Bone–Marrow‐Derived Pluripotent Stem Cells in an Animal Model of Auditory Neuropathy
Authors: Matsuoka Akihiro J. , Kondo Takako , Miyamoto Richard T. , Hashino Eri
Published: July 2007

Objective: The loss of spiral ganglion neurons (SGNs) is one of the major causes of profound sensorineural hearing loss (SNHL). Stem cell replacement therapy, which is still in its infancy, has the potential to treat or cure those who suffer from an array of illnesses and degenerative neurologic disorders, including sensorineural deafness (SNHL). Little is known about the potentials of mesenchymal stem cells (MSCs) and their ability to take on properties of SGNs. The two main purposes of this study were to evaluate the survival of mouse MSCs transplanted into normal and ouabain‐treated gerbil cochleae and to determine the migratory patterns of MSCs with two differing injection methods.

Subjects: Thirty‐two Mongolian gerbils, 3 to 4 months old, were used as recipients, and four 6‐week‐old TgN(ACTbEGFP) mice that ubiquitously express green fluorescent protein (GFP) were used as donors.

Design: The animals were deafened by ouabain, which damaged SGNs while leaving hair cell systems intact. After 4 weeks of recovery, the animals received an intraperilymphatic transplantation of 1.0 × 106 GFP‐positive undifferentiated MSCs via two different injection methods: scala tympani injection and modiolar injection. Seven days after the transplantation, the survival of MSCs was evaluated by microscopic examination of frozen sections cut through the cochleae of the recipient animals. The number of profiles was counted on the five most central modiolar sections. One‐way analyses of variance (ANOVA) were used to determine any significantdifferences among mean profile counts across the experimental conditions.

Results: Our findings indicated that undifferentiated MSCs were able to survive in the modiolus both in the control and the ouabain‐treated cochleae. The average number of profiles found in the modiolus was greater in the ouabain‐treated cochleae than in the control cochleae. This difference was statistically significant (P < .01) as determined using a one‐way ANOVA and an ad hoc Tukey‐Kramer's test. With the scala tympani injection, there were no profiles found in the modiolus either in the control or ouabain‐treated cochleae. This finding may indicate that donor MSCs need to be directly injected into the modiolus to replace injured SGNs. Finally, there was no evidence of hyperacute rejection in any of the gerbils despite the use of xenotransplantation.

Conclusions: These findings may have important clinical implications as a means of delivering MSCs in the cochlea for stem‐cell replacement therapy. Survival of transplanted MSCs into the modiolus of the cochlea may result in regeneration of damaged SGNs.
Over‐Expression of Neuropeptide Urocortin and Its Receptors in Human Allergic Nasal Mucosa
Authors: Kim Tae Hoon , Lee Sang Hag , Lee Heung Man , Lee Seung Hoon , Lee Se Woo , Kim Woo Joo , Park Se Jin , Kim Yang Soo , Choe Hwan , Hwang Ho Yeon , Yoo Ik One
Published: July 2007

Objectives: Urocortin (UCN) is a member of the corticotropin releasing factor (CRF) neuropeptide family. UCN act as locally expressed proinflammatory factor and induce mast cell degranulation, cytokine secretion, and trigger vascular permeability, which are mediated by CRF receptors in peripheral tissues. Considering its functional roles, UCN and its receptors may play a role in the pathogenesis of allergic nasal mucosa. Therefore, we investigated the expression profile and distribution of UCN and CRF receptors in normal and allergic nasal mucosa.

Methods: Reverse transcriptase‐polymerase chain reaction, immunohistochemistry, and Western blotting were applied to the normal and allergic nasal mucosa.

Results: The expression levels of UCN and CRF receptors were increased in allergic nasal mucosa in comparison with normal nasal mucosa. In normal nasal mucosa, UCN and CRF receptors were restricted to the vascular endothelium of submucosal cavernous sinusoids where faint staining was found. However, in allergic nasal mucosa, UCN was expressed in small vessels distributed in lamina propria and the vascular endothelium of cavernous sinusoid located in submucosa. Many scattered positive cells were also found in allergic nasal mucosa, probably UCN‐positive leukocytes. CRF receptors were also localized in the vascular endothelium of small vessels and cavernous sinusoid.

Conclusions: These results indicate that UCN may play a role in the regulation of vascular swelling in normal nasal mucosa. Moreover, in allergic nasal mucosa, increased expression levels of UCN and its receptors may contribute to increased mucosal swelling and vascular permeability, playing an important role in the pathogenesis of allergic rhinitis.
Vaccinations With Dendritic Cells Primed With Apoptotic Tumor Cells Can Elicit Preventive Antitumor Immunity in a Poorly Immunogenic Animal Model of Squamous Cell Carcinoma
Authors: Jeong Han‐Sin , Lee Hyunah , Ko Yejeung , Son Young‐Ik
Published: July 2007

Background: Dendritic cells (DCs) can effectively mediate the prevention and regression of a variety of solid tumors. However, not much has been determined about their efficacy for the prevention of squamous cell carcinoma (SCC), partly because there are no known tumor‐specific antigens or low immunogenicity for this tumor. The authors aimed to determine the preventive effect of DC‐based immunotherapy in a SCC animal model.

Methods: Bone marrow derived DCs of C3H/He mice were pulsed with ultraviolet–B‐irradiated apoptotic SCCVII cells, which are known as a poorly immunogenic SCC cell line. After the animals were vaccinated with these DCs, a tumorigenic dosage of SCCVII cells was subcutaneously injected and the tumor growth assessed.

Results: Animals pretreated with apoptotic SCCVII cell‐pulsed DCs showed tumor extinction within 2 weeks after forming a small tumor, or there was no tumor formation at all, as seen in 81% of the mice; in the remaining 19% of the mice, tumor growth was significantly retarded compared with the control groups (P = .0029). The SCCVII cell‐specific T‐cell response was observed in the immunized mice.

Conclusion: The adoptive transfer of DCs primed with apoptotic tumor cells can hopefully serve as an effective preventive vaccine, even in poorly immunogenic SCC.
Optical Stimulation of the Facial Nerve: A New Monitoring Technique?
Authors: Teudt Ingo Ulrik , Nevel Adam E. , Izzo Agnella D. , Walsh Joseph T. , Richter Claus‐Peter
Published: July 2007

Objectives/ Hypothesis: One sequela of skull base surgery is iatrogenic damage to cranial nerves, which can be prevented if the nerve is identified. Devices that stimulate nerves with electric current assist in nerve identification. Contemporary devices have two main limitations: 1) the physical contact of the stimulating electrode and (2) the spread of the current through the tissue. In contrast to electrical stimulation, pulsed infrared optical radiation can be used to safely and selectively stimulate neural tissue and might be valuable for screening.

Methods: The gerbil facial nerve was exposed to 250 microsecond pulses of 2.12 μm radiation delivered via a 600‐μm‐diameter optical fiber at a repetition rate of 2 Hz. With use of 27 GA, 12‐mm intradermal electrodes, muscle action potentials were recorded. Nerve samples were examined for possible tissue damage.

Results: Eight facial nerves were stimulated with radiant exposures between 0.71 and 1.77 J/cm2, resulting in compound muscle action potentials (CmAPs) that were simultaneously measured at the m. orbicularis oculi, m. levator nasolabialis, and m. orbicularis oris. Resulting CmAP amplitudes were 0.3 to 0.4 mV, 0.15 to 1.4 mV, and 0.3 to 2.3 mV, respectively, depending on the radial location of the optical fiber and the radiant exposure. Individual nerve branches were also stimulated, resulting in CmAP amplitudes between 0.2 and 1.6 mV. Histology revealed tissue damage at radiant exposures of 2.2 J/cm2 but no apparent damage at radiant exposures of 2.0 J/cm2.

Conclusions: The experiments showed that selective muscle action potentials can be evoked optically in the gerbil facial nerve without direct physical contact.
Adsorption of human serum albumin on the chrysotile surface: a molecular dynamics and spectroscopic investigation
Authors: Artali Roberto , Pra Antonio Del , Foresti Elisabetta , Lesci Isidoro Giorgio , Roveri Norberto , Sabatino Piera
Published: July 2007

The human serum albumin (HSA) secondary structure modifications induced by the chrysotile surface have been investigated via computational molecular dynamics (MD) and experimental infrared spectroscopy (FTIR) on synthetic chrysotile nanocrystals coated with different amount of HSA. MD simulations, conducted by placing various albumin subdomains close to the fixed chrysotile surface, show an initial adsorption phase, accompanied by local rearrangements of the albumin motifs in contact with the chrysotile layer. Next, large-scale rearrangements follow with consequent secondary structure modifications.

Gaussian curve fitting of the FTIR spectra obtained for HSA-coated synthetic chrysotile nanocrystals has allowed the quantification of HSA structural modifications as a function of the amount of protein adsorbed. The experimental results support the atomistic computer simulations providing a realistic description of the adsorption of plasma proteins onto chrysotile and unravelling a key step in the understanding of asbestos toxicity.
A Slicer-independent role for Argonaute 2 in hematopoiesis and the microRNA pathway
Authors: O’Carroll Dónal , Mecklenbrauker Ingrid , Das Partha Pratim , Santana Angela , Koenig Ulrich , Enright Anton J. , Miska Eric A. , Tarakhovsky Alexander
Published: July 2007

Binding of microRNA (miRNA) to mRNA within the RNA-induced silencing complex (RISC) leads to either translational inhibition or to destruction of the target mRNA. Both of these functions are executed by Argonaute 2 (Ago2). Using hematopoiesis in mice as a model system to study the physiological function of Ago2 in vivo, we found that Ago2 controls early development of lymphoid and erythroid cells. We show that the unique and defining feature of Ago2, the Slicer endonuclease activity, is dispensable for hematopoiesis. Instead, we identified Ago2 as a key regulator of miRNA homeostasis. Deficiency in Ago2 impairs miRNA biogenesis from precursor-miRNAs followed by a reduction in miRNA expression levels. Collectively, our data identify Ago2 as a highly specialized member of the Argonaute family with an essential nonredundant Slicer-independent function within the mammalian miRNA pathway.
Low-frequency stimulation induces a pathway-specific late phase of LTP in the amygdala that is mediated by PKA and dependent on protein synthesis
Authors: Huang Yan-You , Kandel Eric R.
Published: July 2007

Activity-dependent changes in synaptic efficacy are thought to be the key cellular mechanism for the formation and storage of both explicit and implicit memory. Different patterns of stimulation can elicit different changes in the efficiency on excitatory synaptic transmission. Here, we examined the synaptic changes in the amygdala of adult mice produced by low-frequency stimulation (1 Hz, 15 min, LFS). We first compared the synaptic changes induced by LFS in three different synaptic pathways of amygdala: cortical–lateral amygdala, thalamic–lateral amygdala, and lateral–basolateral amygdala pathways. We find that the plastic changes induced by LFS are different between synaptic pathways. Low-frequency stimulation selectively elicits a slow onset and protein synthesis-dependent late-phase LTP in the cortical–lateral amygdala pathway, but not in the thalamic–lateral or lateral–basolateral pathways. We next analyzed LTP induced by LFS in the cortical–lateral amygdala pathway and found that three PKA-coupling neurotransmitter receptors are involved: 5-HT4, Dopamine D1, and β-adrenergic receptors. Antagonists of these receptors block the LFS L-LTP, but the effects of agonists of these receptors are clearly different. These results indicate that the threshold for the induction of LFS L-LTP is different among these pathways and that the maintenance of LFS L-LTP requires a cross-talk among multiple neurotransmitters.