bluuebunny/crossref_metadata_2025 huggingface dataset:
Entropy and scintillation analysis of acoustical beam propagation through ocean internal waves
Authors: Morozov Andrey K. , Colosi John A.
Published: March 2005

Parabolic equation numerical simulations of waveguide acoustical beam propagation in an ocean of Garrett–Munk internal waves are used to examine the range evolution of beam properties such as beamwidth (both spectral and spatial), Shannon entropy, and scintillation index, as a function of beam angle. Simulations are carried out at 250- and 125-Hz acoustic frequencies. The ray trajectories associated with these beams are predominantly chaotic or exponentially sensitive to initial conditions and/or medium perturbations. At long range near saturation, the finite-frequency beams show a constant rate of change of Shannon entropy with range, independent of acoustic frequency. This full-wave rate of entropy is of the same order of magnitude as the average rate of entropy for the ray trajectories associated with this beam. Finite-range Lyapunov exponents provide the estimates of ray entropy rate or Kolmogorov–Siani entropy. The correspondence between full-wave and ray entropies suggests a full-wave manifestation of ray chaos, but only once statistical saturation is obtained. In spite of this correspondence, the simulated acoustical beams expand diffusively not exponentially (or explosively).
Rays, modes, wavefield structure, and wavefield stability
Authors: Brown Michael G. , Beron-Vera Francisco J. , Rypina Irina , Udovydchenkov Ilya A.
Published: March 2005

Sound propagation is considered in range-independent environments and environments consisting of a range-independent background on which a weak range-dependent perturbation is superimposed. Recent work on propagation in both types of environments, involving both ray- and mode-based wavefield descriptions, have focused on the importance of α, a ray-based “stability parameter,” and β, a mode-based “waveguide invariant.” It is shown that, when β is evaluated using asymptotic mode theory, β=α. Using both ray and mode concepts, known results relating to the manner by which α (or β) controls both the unperturbed wavefield structure and the stability of the perturbed wavefield are briefly reviewed.
The Kauai Near-Source Test (KNST): Modeling and measurements of downslope propagation near the North Pacific Acoustics Laboratory (NPAL) Kauai source
Authors: Heaney Kevin D.
Published: March 2005

In April 2002, a series of recordings were taken near the North Pacific Acoustic Laboratory (NPAL) Kauai source. This source transmits broadband low-frequency signals to receivers in various locations across the Pacific. Travel-time calculations based upon the nonbottom interacting PE or ray-trace modeling for the Kauai source lagged the actual first arrival by 1 second or so, a disturbing discrepancy that needed answering. The Kauai Near-Source Test (KNST) was designed to take measurements near the Kauai source to examine the effect of the local bathymetry on the signal transmitted into the ocean. Six receptions, using a 100 m VLA, at ranges from 0.2 to 52 km were taken. Parabolic Equation (PE) simulations of the channel impulse response for the measurement ranges are in good agreement with the observations. PE simulations using an exposed basalt seafloor match the data much better than those with a silty-sand cover. A primary result of this test was the indication that there may be significant energy in the first bottom bounce, comparable to the direct-path (purely refracted) ray. This implies that the seafloor near the source influences the arrival times and patterns of the field at long distances, and should be taken into account.
Statistics and vertical directionality of low-frequency ambient noise at the North Pacific Acoustics Laboratory site
Authors: Baggeroer Arthur B. , Scheer Edward K. ,   The NPAL Group, Colosi (J. A. , Cornuelle B. D. , Dushaw B. D. , Dzieciuch M. A. , Howe B. M. , Mercer J. A. , Munk W. H. , Spindel R. C. , Worcester) P. F.
Published: March 2005

We examine statistical and directional properties of the ambient noise in the 10–100 Hz frequency band from the NPAL array. Marginal probability densities are estimated as well as mean square levels, skewness and kurtoses in third octave bands. The kurotoses are markedly different from Gaussian except when only distant shipping is present. Extremal levels reached ∼150 dB re 1 μ Pa, suggesting levels 60dB greater than the mean ambient were common in the NPAL data sets. Generally, these were passing ships. We select four examples: i) quiescent noise, ii) nearby shipping, iii) whale vocalizations and iv) a micro earthquake for the vertical directional properties of the NPAL noise since they are representative of the phenomena encountered. We find there is modest broadband coherence for most of these cases in their occupancy band across the NPAL aperture. Narrowband coherence analysis from VLA to VLA was not successful due to ambiguities. Examples of localizing sources based upon this coherence are included. kw diagrams allow us to use data above the vertical aliasing frequency. Ducted propagation for both the quiescent and micro earthquake (T phase) are identified and the arrival angles of nearby shipping and whale vocalizations. MFP localizations were modestly successful for nearby sources, but long range ones could not be identified, most likely because of signal mismatch in the MFP replica.
Frequency dependence of elastic properties of acoustic foams
Authors: Etchessahar M. , Sahraoui S. , Benyahia L. , Tassin J. F.
Published: March 2005

Polyurethane (PU) and other plastic foams are widely used as passive acoustic absorbers. For optimal design, it is often necessary to know the viscoelastic properties of these materials in the frequency range relevant to their application. A nonresonance technique (dynamic stiffness) based on a forced vibrations procedure is used to investigate the frequency dependent complex shear modulus of a PU foam. This modulus is first measured, in a quasistatic configuration, in the frequency range (0.016–16 Hz) at different temperatures between 0 and 20 °C. It is afterwards predicted over a wide frequency range (0.01–3000 Hz) using the frequency-temperature superposition principle. The validation of this principle is discussed through quasistatic experiments. Under the assumption that Poisson’s ratio of polymeric foams is real and frequency independent on the frequency range used, the frequency dependence of the complex shear modulus obtained is used to predict the complex stiffness of the acoustic foam on a wide frequency range.
Full-scale measurements for noise transmission in tunnels
Authors: Li K. M. , Iu K. K.
Published: March 2005

In many previous studies, energy-based methods are used to predict the attenuation of sound in long tunnels. However, these models do not address the interference effects of the sound fields generated by all image sources. A numerical model has been developed, in which the total sound field is computed by summing contributions from all image sources coherently. This numerical model also incorporates a correction term for calculating the atmospheric absorption of sound in air. To validate the numerical models in practical situations, two road traffic tunnels have been chosen for extensive measurements. The levels of the transmitted noise have been recorded in one-third octave band frequencies at various separations up to a maximum of 400 m. The predictions using the coherent model agree reasonably well with the measured data at all frequencies. The agreements between the field data and the theoretical predictions using the energy-based model are tolerable at high frequency, but less so at low frequency. In most cases, the predictions of the coherent model give the best results, with an accuracy to within 3 dB. On the other hand, the energy-based models are not able to predict the peaks and dips across the frequency spectra, the variance with the measurement results being up to 7 dB at low-frequency bands.
EUKARYOTIC CYTOSINE METHYLTRANSFERASES
Authors: Goll Mary Grace , Bestor Timothy H.
Published: March 2005

▪ Abstract  Large-genome eukaryotes use heritable cytosine methylation to silence promoters, especially those associated with transposons and imprinted genes. Cytosine methylation does not reinforce or replace ancestral gene regulation pathways but instead endows methylated genomes with the ability to repress specific promoters in a manner that is buffered against changes in the internal and external environment. Recent studies have shown that the targeting of de novo methylation depends on multiple inputs; these include the interaction of repeated sequences, local states of histone lysine methylation, small RNAs and components of the RNAi pathway, and divergent and catalytically inert cytosine methyltransferase homologues that have acquired regulatory roles. There are multiple families of DNA (cytosine-5) methyltransferases in eukaryotes, and each family appears to be controlled by different regulatory inputs. Sequence-specific DNA-binding proteins, which regulate most aspects of gene expression, do not appear to be involved in the establishment or maintenance of genomic methylation patterns.
Gene expression signature of estrogen receptor α status in breast cancer
Authors: Abba Martín C , Hu Yuhui , Sun Hongxia , Drake Jeffrey A , Gaddis Sally , Baggerly Keith , Sahin Aysegul , Aldaz C Marcelo
Published: March 2005

Background

Estrogens are known to regulate the proliferation of breast cancer cells and to modify their phenotypic properties. Identification of estrogen-regulated genes in human breast tumors is an essential step toward understanding the molecular mechanisms of estrogen action in cancer. To this end we generated and compared the Serial Analysis of Gene Expression (SAGE) profiles of 26 human breast carcinomas based on their estrogen receptor α (ER) status. Thus, producing a breast cancer SAGE database of almost 2.5 million tags, representing over 50,000 transcripts.

Results

We identified 520 transcripts differentially expressed between ERα-positive (+) and ERα-negative (-) primary breast tumors (Fold change ≥ 2; p < 0.05). Furthermore, we identified 220 high-affinity Estrogen Responsive Elements (EREs) distributed on the promoter regions of 163 out of the 473 up-modulated genes in ERα (+) breast tumors. In brief, we observed predominantly up-regulation of cell growth related genes, DNA binding and transcription factor activity related genes based on Gene Ontology (GO) biological functional annotation. GO terms over-representation analysis showed a statistically significant enrichment of various transcript families including: metal ion binding related transcripts (p = 0.011), calcium ion binding related transcripts (p = 0.033) and steroid hormone receptor activity related transcripts (p = 0.031). SAGE data associated with ERα status was compared with reported information from breast cancer DNA microarrays studies. A significant proportion of ERα associated gene expression changes was validated by this cross-platform comparison. However, our SAGE study also identified novel sets of genes as highly expressed in ERα (+) invasive breast tumors not previously reported. These observations were further validated in an independent set of human breast tumors by means of real time RT-PCR.

Conclusion

The integration of the breast cancer comparative transcriptome analysis based on ERα status coupled to the genome-wide identification of high-affinity EREs and GO over-representation analysis, provide useful information for validation and discovery of signaling networks related to estrogen response in this malignancy.
Analyses of the differentiation potential of satellite cells from myoD
-/-, mdx, and PMP22 C22 mice
Authors: Schuierer Marion M , Mann Christopher J , Bildsoe Heidi , Huxley Clare , Hughes Simon M
Published: March 2005

Background

Sporadic and sometimes contradictory studies have indicated changes in satellite cell behaviour associated with the progressive nature of human Duchenne muscular dystrophy (DMD). Satellite cell proliferation and number are reportedly altered in DMD and the mdx mouse model. We recently found that satellite cells in MSVski transgenic mice, a muscle hypertrophy model showing progressive muscle degeneration, display a severe ageing-related differentiation defect in vitro. We tested the hypothesis that similar changes contribute to the gradual loss of muscle function with age in mdx and PMP22 mice, a model of human motor and sensory neuropathy type 1A (HMSN1A).

Methods

Single extensor digitorum longus muscle fibres were cultured from mdx and PMP22 mice and age- and genetic background-matched controls. Mice at several ages were compared with regard to the differentiation of satellite cells, assayed as the proportion of desmin-expressing cells that accumulated sarcomeric myosin heavy chain.

Results

Satellite cells of 2 month, 6 month, and 12 month old mdx mice were capable of differentiating to a similar extent to age-matched wild type control animals in an in vitro proliferation/differentiation model. Strikingly, differentiation efficiency in individual 6 month and 12 month old mdx animals varies to a much higher extent than in age-matched controls, younger mdx animals, or PMP22 mice. In contrast, differentiation of myoblasts from all myoD null mice assayed was severely impaired in this assay system. The defect in satellite cell differentiation that occurs in some mdx animals arises from a delay in differentiation that is not overcome by IGF-1 treatment at any phase of cultivation.

Conclusion

Overall, a defect in satellite cell differentiation above that arising through normal ageing does not occur in mdx or PMP22 mouse models of human disease. Nonetheless, the impaired differentiation of satellite cells from some mdx animals suggests that additional factors, environmental or epigenetic, may lead to deteriorating muscle repair through poor differentiation of satellite cells in genetically predisposed individuals.
Screening of crude extracts of six medicinal plants used in South-West Nigerian unorthodox medicine for anti-methicillin resistant Staphylococcus aureus activity
Authors: Akinyemi Kabir O , Oladapo Olukayode , Okwara Chidi E , Ibe Christopher C , Fasure Kehinde A
Published: March 2005

Background

Six Nigerian medicinal plants Terminalia avicennioides, Phylantus discoideus, Bridella ferruginea, Ageratum conyzoides, Ocimum gratissimum and Acalypha wilkesiana used by traditional medical practitioners for the treatment of several ailments of microbial and non-microbial origins were investigated for in vitro anti-methicillin Resistant Staphylococcus aureus (MRSA) activity.

Methods

Fresh plant materials were collected from the users. Water and ethanol extracts of the shredded plants were obtained by standard methods. The Bacterial cultures used were strains of MRSA isolated from patients. MRSA was determined by the reference broth microdilution methods using the established National Committee for Clinical Laboratory Standards break points. Staphylococcus aureus NCIB 8588 was used as a standard strain. Susceptibility testing and phytochemical screening of the plant extracts were performed by standard procedures. Controls were maintained for each test batch.

Results

Both water and ethanol extracts of T. avicennioides, P. discoideus, O. gratissimum, and A. wilkesiana were effective on MRSA. The Minimum Inhibition Concentration (MIC) and Minimum Bactericidal Concentration (MBC) of the ethanol extracts of these plants range from 18.2 to 24.0 mcg/ml and 30.4 to 37.0 mcg/ml respectively. In contrast, MIC range of 30.6 to 43.0 mcg/ml and 55.4 to 71.0 mcg/ml were recorded for ethanol and water extracts of B. ferruginea, and A. conyzoides respectively. Higher MBC values were obtained for the two plants. These concentrations were too high to be considered active in this study. All the four active plants contained at least trace amount of anthraquinones.

Conclusion

Our results offer a scientific basis for the traditional use of water and ethanol extracts of A. wilkesiana, O. gratissimum, T. avicennioides and P. discoideus against MRSA-associated diseases. However, B. ferruginea and A. conyzoides were ineffective in vitro in this study; we therefore suggest the immediate stoppage of their traditional use against MRSA-associated diseases in Lagos, Nigeria.
International variation in prescribing antihypertensive drugs: Its extent and possible explanations
Authors: Fretheim Atle , Oxman Andrew D
Published: March 2005

Background

Inexpensive antihypertensive drugs are at least as effective and safe as more expensive drugs. Overuse of newer, more expensive antihypertensive drugs is a poor use of resources. The potential savings are substantial, but vary across countries, in large part due to differences in prescribing patterns. We wanted to describe prescribing patterns of antihypertensive drugs in ten countries and explore possible reasons for inter-country variation.

Methods

National prescribing profiles were determined based on information on sales and indications for prescribing. We sent a questionnaire to academics and drug regulatory agencies in Canada, France, Germany, UK, US and the Nordic countries, asking about explanations for differences in prescribing patterns in their country compared with the other countries. We also conducted telephone interviews with medical directors of drug companies in the UK and Norway, the countries with the largest differences in prescribing patterns.

Results

There is considerable variation in prescribing patterns. In the UK thiazides account for 25% of consumption, while the corresponding figure for Norway is 6%. In Norway alpha-blocking agents account for 8% of consumption, which is more than twice the percentage found in any of the other countries. Suggested factors to explain inter-country variation included reimbursement policies, traditions, opinion leaders with conflicts of interests, domestic pharmaceutical production, and clinical practice guidelines. The medical directors also suggested hypotheses that: Norwegian physicians are early adopters of new interventions while the British are more conservative; there are many clinical trials conducted in Norway involving many general practitioners; there is higher cost-awareness among physicians in the UK, in part due to fund holding; and there are publicly funded pharmaceutical advisors in the UK.

Conclusion

Two compelling explanations the variation in prescribing that warrant further investigation are the promotion of less-expensive drugs by pharmaceutical advisors in UK and the promotion of more expensive drugs through "seeding trials" in Norway.
Isolation of Aspergillus spp. from the respiratory tract in critically ill patients: risk factors, clinical presentation and outcome
Authors: Garnacho-Montero José , Amaya-Villar Rosario , Ortiz-Leyba Carlos , León Cristóbal , Álvarez-Lerma Francisco , Nolla-Salas Juan , Iruretagoyena José R , Barcenilla Fernando
Published: March 2005

Introduction

Our aims were to assess risk factors, clinical features, management and outcomes in critically ill patients in whom Aspergillus spp. were isolated from respiratory secretions, using a database from a study designed to assess fungal infections.

Methods

A multicentre prospective study was conducted over a 9-month period in 73 intensive care units (ICUs) and included patients with an ICU stay longer than 7 days. Tracheal aspirate and urine samples, and oropharyngeal and gastric swabs were collected and cultured each week. On admission to the ICU and at the initiation of antifungal therapy, the severity of illness was evaluated using the Acute Physiology and Chronic Health Evaluation II score. Retrospectively, isolation of Aspergillus spp. was considered to reflect colonization if the patient did not fulfil criteria for pneumonia, and infection if the patient met criteria for pulmonary infection and if the clinician in charge considered the isolation to be clinically valuable. Risk factors, antifungal use and duration of therapy were noted.

Results

Out of a total of 1756 patients, Aspergillus spp. were recovered in 36. Treatment with steroids (odds ratio = 4.5) and chronic obstructive pulmonary disease (odds ratio = 2.9) were significantly associated with Aspergillus spp. isolation in multivariate analysis. In 14 patients isolation of Aspergillus spp. was interpreted as colonization, in 20 it was interpreted as invasive aspergillosis, and two cases were not classified. The mortality rates were 50% in the colonization group and 80% in the invasive infection group. Autopsy was performed in five patients with clinically suspected infection and confirmed the diagnosis in all of these cases.

Conclusion

In critically ill patients, treatment should be considered if features of pulmonary infection are present and Aspergillus spp. are isolated from respiratory secretions.
In vitro assessment of the osteointegrative potential of a novel multiphase anodic spark deposition coating for orthopaedic and dental implants
Authors: Sandrini Enrico , Morris Christopher , Chiesa Roberto , Cigada Alberto , Santin Matteo
Published: March 2005

Hydroxyapatite coatings have been proven to improve the osteointegration of metal implants through a tight binding to the bone mineral phase as well as through favorable osteoblast adhesion and proliferation onto the implant surface. However, hydroxyapatite coatings are not stable and they tend to delaminate from the metal surface when challenged by the mechanical stresses experienced by the implant. Recently, a new multiphase anodic spark deposition (ASD) method has been optimized where the formation of a thick oxide film is followed by the deposition of a calcium phosphate mineral phase and its etching by alkali. The data in this paper demonstrate that this novel type of coating, BioSpark™, improves the material osteointegration potential when compared to conventional ASD while offering more mechanical stability. A faster mineralization was obtained by incubation in simulated body fluids and osteoblasts showed better adhesion, proliferation, differentiation, and collagen production. These performances were related to the surface morphology, to the film calcium/phosphate ratio and its surface oxygen content, as well as to a preferential binding of structural proteins such as fibronectin. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater
Mapping of the b value anomalies beneath Mt. Etna, Italy, during July–August 2001 lateral eruption
Authors: Murru M. , Montuori C. , Console R. , Lisi A.
Published: March 2005

The pattern of b value of the frequency‐magnitude relation, or mean magnitude, has been analyzed as function of space beneath Mt. Etna during the intense lateral eruption of July–August 2001. The data used (August 1999–August 2001), subdivided in the pre‐eruptive and eruption period, show significant space variations in the b value. For each of the two periods, a volume of anomalously high b value can be observed in the southeastern flank of the volcano. The anomalies located at 3 ± 1 km (b = 1.84 ± 0.20), and at about 1 ± 1 km (b = 2.11 ± 0.29) depth are interpreted as two different steps of a magma migration process ended with the July–August 2001 eruption. All the available geophysical evidences such as geodetic deformation measurements, focal mechanism and tomographic studies support this interpretation.
Relative location of excavation induced microseismicity at the Underground Research Laboratory (AECL, Canada) using surveyed reference events
Authors: Reyes‐Montes J. M. , Rietbrock A. , Collins D. S. , Young R. P.
Published: March 2005

Microseismicity is extensively used to monitor induced damage accumulation and stability of underground structures. Classical location routines in this context can often not resolve the potential coalescence of the induced microcracks, since the location accuracy is on the order of magnitude of the largest fractures observed. Most of the uncertainty arises from the poor knowledge of the seismic velocity field. Master event relocation techniques can circumvent this problem and significantly improve the accuracy in hypocenter determination. We relocate events recorded during the excavation of the TSX tunnel at the Underground Research Laboratory (URL) and show that the resolution is enhanced by up to one order of magnitude. The relocated events locate closer to the excavation perimeter than the absolute locations, a result that corresponds with the observed damage. Additionally the relocated events define a clearer structure, with planes of alignment parallel to the tunnel perimeter.
Profile observations of the Saharan air layer during AEROSE 2004
Authors: Nalli Nicholas R. , Clemente‐Colón Pablo , Morris Vernon , Joseph Everette , Szczodrak Malgorzata , Minnett Peter J. , Shannahoff Jonathan , Goldberg Mitchell D. , Barnet Chris , Wolf Walter W. , Feltz Wayne F. , Knuteson Robert O.
Published: March 2005

This paper describes 3‐hourly radiosonde observations of the Saharan air layer (SAL) acquired from the NOAA Ship Ronald H. Brown during the 2004 Aerosol and Ocean Science Expedition (AEROSE). The sampling frequency allows for unique vertical cross‐sectional analyses of SAL phenomena, including dust events detected by shipboard Sun photometers, observed during March 2004. The observational analyses provide, for the first time, a coherent, 2‐dimensional space‐time depiction of the SAL as an expansive warm, dry, stable column located above the marine boundary layer. Midlevel easterly wind maxima are also observed to occur near the leading edge of the dry layers. The AEROSE sounding data will be useful for studies of the SAL, as well as for validation of environmental satellite sensors, especially the Aqua Atmospheric Infrared Sounder (AIRS).
Nonlinear wave interactions as a model for naturally enhanced ion acoustic lines in the ionosphere
Authors: Kontar E. P. , Pécseli H. L.
Published: March 2005

Incoherent radar scatter from the ionosphere will, for equilibrium conditions, show two symmetric ion‐acoustic lines, one for each direction of wave propagation. Many observations, from the EISCAT Svalbard Radar (ESR) for instance, demonstrate that the symmetry of this ion line can be broken. An enhanced, nonthermal, level of fluctuations, i.e., Naturally Enhanced Ion‐Acoustic Lines (NEIALs) might be observed. Several models have been proposed for explaining these naturally enhanced lines. Here, we consider one of these, suggesting that decay of electron beam excited Langmuir waves gives rise to enhanced asymmetric ion lines in the ionosphere. We use a weak‐turbulence approximation, and identify crucial parameters for Langmuir decay processes to be effective in generating the observed signals.
Relict Proterozoic basement in the Nanling Mountains (SE China) and its tectonothermal overprinting
Authors: Xu Xisheng , O'Reilly S. Y. , Griffin W. L. , Deng Ping , Pearson N. J.
Published: March 2005

The basement beneath the Caledonian belt in SE China has been overprinted by Indosinian and Yanshanian events and is poorly known. In situ U‐Pb and Hf‐isotope analysis of zircons from granites and surrounding rocks in the Nanling Mountains area of the fold belt reveal that the Lanhe felsic gneiss is an outcrop of Mesoproterozoic basement, probably with a partly Late Archean protolith. This is consistent with Nd model ages of granites in this region, and exposures of Cathaysia basement in the coastal area of SE China. In the Nanling Mountains, this basement was reactivated to generate granitoid rocks during the Caledonian, Indosinian, and Yanshanian tectonothermal events. The Caledonian overprint is documented in extensive exposures of the Zhuguang migmatites (425–470 Ma) and by previous U‐Pb zircon dating of adjacent granites. The Jiangnan granite may be of similar age, but strongly reworked. The Indosinian overprint resulted in the formation of granites such as the Luxi and Xiazhuang bodies (233–246 Ma) in the Guidong complex. The Yanshanian overprint produced the most widely distributed granites (circa 160 Ma) such as the Jiufeng and Fogang bodies, and parts of the Guidong complex. Hf‐isotope data show that all of the Phanerozoic magmatic rocks were derived from the Mesoproterozoic basement (and minor Archean components), without obvious contributions from juvenile sources. The presence of zircons with Archean age (2.5–2.7 Ga) in both the Lanhe gneiss and Devonian sediments indicates that the Badu and Mayuan groups may not be the oldest basement of the Cathaysia block. Some Archean basement (circa 2.5–2.7 Ga) may still be exposed but unrecognized in this region, and Cathaysia may include Archean microcontinental fragments.
Inversion time of large spins
Authors: Karatsuba Ekatherina A. , Moretti Paolo
Published: March 2005

In order to find an accurate expression for the inversion probability of a large spin, an asymptotic expansion in series of Bessel functions is found, and a formula for the inversion time is obtained.
Synthesis of GaN nanotip triangle pyramids on 3C–SiC epilayer/Si substrates via an in situ In-doping technique
Authors: Dai L. , Liu S. F. , Fu Z. X. , You L. P. , Zhu J. J. , Lin B. X. , Zhang J. C. , Qin G. G.
Published: March 2005

GaN nanotip triangle pyramids were synthesized on 3C–SiC epilayer via an isoelectronic In-doping technique. The synthesis was carried out in a specially designed two-hot-boat chemical vapor deposition system. In (99.999%) and molten Ga (99.99%) with a mass ratio of about 1:4 were used as the source, and pieces of Si (111) wafer covered with 400–500nm 3C–SiC epilayer were used as the substrates. The products were analyzed by x-ray diffraction, field emission scanning electron microscopy, high-resolution transmission electron microscopy, selected area electron diffraction, Raman spectroscopy, and photoluminescence measurements. Our results show that the as-synthesized GaN pyramids are perfect single crystal with wurtzite structure, which may have potential applications in electronic/photonic devices.
Electronic excitation energies of molecules in solution: State specific and linear response methods for nonequilibrium continuum solvation models
Authors: Cammi R. , Corni S. , Mennucci B. , Tomasi J.
Published: March 2005

We present a formal comparison between the two different approaches to the calculation of electronic excitation energies of molecules in solution within the continuum solvation model framework, taking also into account nonequilibrium effects. These two approaches, one based on the explicit evaluation of the excited state wave function of the solute and the other based on the linear response theory, are here proven to give formally different expressions for the excitation energies even when exact eigenstates are considered. Calculations performed for some illustrative examples show that this formal difference has sensible effects on absolute solvatochromic shifts (i.e., with respect to gas phase) while it has small effects on relative (i.e., nonpolar to polar solvent) solvatochromic shifts.
Local environment of Mn dopant in ZnO by near-edge x-ray absorption fine structure analysis
Authors: Kunisu Masahiro , Oba Fumiyasu , Ikeno Hidekazu , Tanaka Isao , Yamamoto Tomoyuki
Published: March 2005

High-resolution near-edge x-ray absorption fine structure (NEXAFS) at MnK edge is employed to probe the local environment of Mn dopant in ZnO. First-principles supercell calculations are systematically made to obtain theoretical NEXAFS. Mn is found to substitute for Zn up to 5at.%Mn in polycrystalline samples sintered at 1623K in air. Presence of Mn3O4 is apparent for samples with higher Mn content. The NEXAFS does not change in the range of Mn concentration from 0.01 to 5at.%, indicating the absence of Mn precipitates. The results are confirmed by examining the polarization dependence of the NEXAFS for a 5at.%-doped ZnO thin film.
Fabrication of microvessels and microlenses from polymers by solvent droplets
Authors: Bonaccurso Elmar , Butt Hans-Jürgen , Hankeln Benjamin , Niesenhaus Brigitte , Graf Karlheinz
Published: March 2005

A process for the fabrication of microvessels and microlenses in polymers is presented. A drop of solvent (diameter between 15 and 150μm) is deposited by an ink-jet method onto a flat polymer substrate. After evaporation of the solvent a lenticular cavity of dimensions comparable to the former drop size is created. This cavity can be employed as a microreaction vessel, as a concave lens, or as a template for a convex lens. Diameter, depth, position, and arrangement of the microvessels on the surface can be controlled.
A proinflammatory chemokine, CCL3, sensitizes the heat- and capsaicin-gated ion channel TRPV1
Authors: Zhang Ning , Inan Sadeet , Cowan Alan , Sun Ronghua , Wang Ji Ming , Rogers Thomas J. , Caterina Michael , Oppenheim Joost J.
Published: March 2005

Pain, a critical component of host defense, is one hallmark of the inflammatory response. We therefore hypothesized that pain might be exacerbated by proinflammatory chemokines. To test this hypothesis, CCR1 was cotransfected into human embryonic kidney (HEK)293 cells together with transient receptor potential vanilloid 1 (TRPV1), a cation channel required for certain types of thermal hyperalgesia. In these cells, capsaicin and anandamide induced Ca
2+
influx mediated by TRPV1. When CCR1:TRPV1/HEK293 cells were pretreated with CCL3, the sensitivity of TRPV1, as indicated by the Ca
2+
influx, was increased ≈3-fold. RT-PCR analysis showed that a spectrum of chemokine and cytokine receptors is expressed in rat dorsal root ganglia (DRG). Immunohistochemical staining of DRG showed that CCR1 is coexpressed with TRPV1 in >85% of small-diameter neurons. CCR1 on DRG neurons was functional, as demonstrated by CCL3-induced Ca
2+
ion influx and PKC activation. Pretreatment with CCL3 enhanced the response of DRG neurons to capsaicin or anandamide. This sensitization was inhibited by pertussis toxin, U73122, or chelerythrine chloride, inhibitors of Gi-protein, phospholipase C, and protein kinase C, respectively. Intraplantar injection of mice with CCL3 decreased their hot-plate response latency. That a proinflammatory chemokine, by interacting with its receptor on small-diameter neurons, sensitizes TRPV1 reveals a previously undescribed mechanism of receptor cross-sensitization that may contribute to hyperalgesia during inflammation.
Incorporating gene-specific variation when inferring and evaluating optimal evolutionary tree topologies from multilocus sequence data
Authors: Seo Tae-Kun , Kishino Hirohisa , Thorne Jeffrey L.
Published: March 2005

Because of the increase of genomic data, multiple genes are often available for the inference of phylogenetic relationships. The simple approach for combining multiple genes from the same taxon is to concatenate the sequences and then ignore the fact that different positions in the concatenated sequence came from different genes. Here, we discuss two criteria for inferring the optimal tree topology from data sets with multiple genes. These criteria are designed for multigene data sets where gene-specific evolutionary features are too important to ignore. One criterion is conventional and is obtained by taking the sum of log-likelihoods over all genes. The other criterion is obtained by dividing the log-likelihood for a gene by its sequence length and then taking the arithmetic mean over genes of these ratios. A similar strategy could be adopted with parsimony scores. The optimal tree is then declared to be the one for which the sum or the arithmetic mean is maximized. These criteria are justified within a two-stage hierarchical framework. The first level of the hierarchy represents gene-specific evolutionary features, and the second represents site-specific features for given genes. For testing significance of the optimal topology, we suggest a two-stage bootstrap procedure that involves resampling genes and then resampling alignment columns within resampled genes. An advantage of this procedure over concatenation is that it can effectively account for gene-specific evolutionary features. We discuss the applicability of the two-stage bootstrap idea to the Kishino–Hasegawa test and the Shimodaira–Hasegawa test.
PTEN as an effector in the signaling of antimigratory G protein-coupled receptor
Authors: Sanchez Teresa , Thangada Shobha , Wu Ming-Tao , Kontos Christopher D. , Wu Dianqing , Wu Hong , Hla Timothy
Published: March 2005

PTEN, a tumor suppressor phosphatase, is important in the regulation of cell migration and invasion. Physiological regulation of PTEN (phosphatase and tensin homolog deleted on chromosome 10) by cell surface receptors has not been described. Here, we show that the bioactive lipid sphingosine 1-phosphate (S1P), which acts through the S1P2 receptor (S1P2R) G protein-coupled receptor (GPCR) to inhibit cell migration, utilizes PTEN as a signaling intermediate. S1P2R inhibition of cell migration is abrogated by dominant-negative PTEN expression. S1P was unable to efficiently inhibit the migration of
Pten

ΔloxP/ΔloxP

mouse embryonic fibroblasts; however, the antimigratory effect was restored upon the expression of PTEN. S1P2R activation of Rho GTPase is not affected in
Pten

ΔloxP/ΔloxP

cells, and dominant-negative Rho GTPase reversed S1P inhibition of cell migration in WT cells but not in
Pten

ΔloxP/ΔloxP

cells, suggesting that PTEN acts downstream of the Rho GTPase. Ligand activation of the S1P2R receptor stimulated the coimmunoprecipitation of S1P2R and PTEN. Interestingly, S1P2R signaling increased PTEN phosphatase activity in membrane fractions. Furthermore, tyrosine phosphorylation of PTEN was stimulated by S1P2R signaling. These data suggest that the S1P2R receptor actively regulates the PTEN phosphatase by a Rho GTPase-dependent pathway to inhibit cell migration. GPCR regulation of PTEN maybe a general mechanism in signaling events of cell migration and invasion.
Introduction Gender and Conversion in Colonial India
Authors: Kent Eliza F.
Published: March 2005

This introductory chapter begins with a discussion on the concepts of conversion and gender, to establish the theoretical framework of this study on Indian Christian converts in the Madras Presidency. It argues that in the late 19th and early 20th century, a “discourse of respectability” emerged among Christian communities in the south of the Madras Presidency during the British Raj, which radically transformed the style of femininity to which Indian Christian women were expected to conform. This is followed by an overview of the chapters included in this volume.
Agency and Transnational Movements
Authors: Nepstad Sharon Erickson
Published: March 2005

A sociological understanding of agency requires an assessment of the structural factors and cultural expectations that shape the ability to form movements and foster change. There is a need to understand the constraints and opportunities afforded by activists’ social traits, structural location, and the historical context in which they operate. This chapter discusses how these factors conditioned the ability of church workers to organize, build, and sustain the Central American solidarity movement.
From Ideologies to Parties
Authors: Ignazi Piero
Published: March 2005

This chapter explores the ideology and evolution of the extreme right. Historians and political philosophers have attributed the ideologies of ‘counter-revolutionism’ and ‘fascism’ to this term. However, in the 1980s, a new set of ideas entered the political discourse of the right; fascism and its variants no longer remained the unique cultural sources. Two types of extreme right parties have emerged: traditional extreme right parties, and post-industrial parties.
Absolute State and Patrimonial Administration
Authors: Bresser-Pereira Luiz Carlos
Published: March 2005

State formation to be an essential part of the capitalist revolution and of the modernization process that begins with the Renaissance and the commercial revolution. Its completion, which happened with the industrial revolution, required definite and regulated markets, which were brought by the absolute state. Hypothetically, the absolute state was the outcome of a Hobbesian social contract; in actual terms, the consequence of a historical agreement between the monarch and the new emerging merchant bourgeoisie at the expense of the feudal lords’ power. The monarch used tax revenues to maintain a dependent patrimonial aristocracy, living at the court, to take care of war, and a patrimonial bureaucracy to collect taxes and administer justice. It is a mistake to see patrimonial administration as merely corrupt and inefficient. Under such bureaucracy, the state apparatus advanced hugely in the seventeenth and eighteenth century.
The Social-Democratic State
Authors: Bresser-Pereira Luiz Carlos
Published: March 2005

The social democratic state rises from the Great Depression and Second Word War. And up to the 1970s, the capitalist economies grow enormously, at the same time that social rights were recognized and the welfare state implemented. The tax burden and the state apparatus grow to face the new social and developmental activities taken on by the state. With the social state emerges plural or public opinion democracy. Political elites diversify, including increasing representatives of the professional middle class. Capitalism also diversifies, and we can detect four models of capitalism: the Anglo-Saxon market model, the European social model, the Asian developmental model, and the Latin American mixed model of capitalism. Particularly in the later two models, a developmental bureaucracy rises.
The Crisis of the Social-Democratic State
Authors: Bresser-Pereira Luiz Carlos
Published: March 2005

The size of the state increased continuously since late nineteenth century, if we measure it by expenditures in relation to GDP. Growth leads cyclically to crisis. State intervention or regulation takes place according to a cyclical pattern. The social-democratic state was successful in promoting economic growth and social justice in the developed countries between the 1930s and the 1970s. In this last decade, however, three different, though related, historical processes–the neo-liberal ideological wave, globalization, and the fiscal crisis of the state–gained momentum and led the social-democratic state into crisis, aiding the transition to the social-liberal state. The fiscal crisis evolved from a distorted and excessive growth of the state; the other two factors were exogenous to the state organization.
The Social-Liberal State
Authors: Bresser-Pereira Luiz Carlos
Published: March 2005

The political values involved in liberalism, democracy, socialism have historically been in conflict, but there is no reason why we cannot see them as complementary. A purely market as well as a fully state-coordinated economy never existed in history. The concepts of liberalism and socialism are elusive ones but they have one common origin: the capitalist revolution and modernity. The social-liberal state that is emerging out of the crisis of the social-democratic state is social because it maintains socialist commitments to social rights, while it gives more room for market competition in the coordination of the economy. It is also social-liberal because, in the social-democratic state, civil servants directly provide social and scientific services, whereas in the social-liberal state, competitive non-profit organizations contacted out and financed by the state already are or will be in charge.
The Republican State
Authors: Bresser-Pereira Luiz Carlos
Published: March 2005

The social-democratic state existing in advanced democracies is gradually changing into a republican state. The ultra-liberal wave failed because modern societies need a strong, not a weak, state. A republican state is strong enough to protect itself and the public patrimony from private capture. Its strength originates in governments’ political legitimacy, in the active participation of citizens organized in civil society, in a dense public space where social accountability and public debate take place, and on the existence of politicians and civil servants endowed with republican virtues. The republican state that is emerging is fiscally strong because it limits its debts, it is administratively strong because it is engaged in public management reform, and it is politically strong because citizens, politicians, and civil servants know that the principles ruling politics are not the same that rule markets: besides the private, the public interest must be taken into consideration. Undertakes a short survey of the literature on republicanism to substantiate these claims.
The Basic Model
Authors: Bresser-Pereira Luiz Carlos
Published: March 2005

Discusses the basic model of public management reform, using a simple matrix. The state’s roles are defined in terms of the relevant forms of ownership in contemporary capitalism. They are state ownership, public non-state ownership, corporative ownership, and private ownership. On the other hand, we have the exclusive activities of the state, the social and scientific services, and the production of goods and services for the markets. State property or organization applies only to the exclusive state activities; public non-state organizations are supposed to provide social and scientific services mostly financed by the state; corporative organizations, such as unions and association, will take care of corporative activities; and private organizations will perform the production of goods and services form the market. Within the state organization, we have the strategic core, in which policies and laws are defined, and agencies. Only in the strategic core, effectiveness is more important than efficiency, and public management must be combined with bureaucratic public administration.
What Constitutes the Mind‐Body Problem?
Authors: McGinn Colin
Published: March 2005

The source and nature of the mind-body problem – the problem of relating consciousness and the brain – is diagnosed. With Russell’s distinction between knowledge by description and knowledge by acquaintance in mind, McGinn suggests that our knowledge of the essence of consciousness is acquired by acquaintance, and that this justifiably produces our sense of the problem. Since knowledge by acquaintance is complete but not reducible to propositional knowledge, it may be that our knowledge of consciousness gives us insight into its essence which cannot be formulated propositionally: we know the nature of consciousness but cannot say what it is in the form of truths about consciousness. It is further argued that the properties of consciousness, which make it problematically related to the brain – its subjectivity and intentionality, its being essentially reflective and known infallibly – are consequential rather than intrinsic aspects of the nature of consciousness. It is explained how the fact that we know by this form of introspective self-consciousness that there is a mind-body problem means that we shall be unable in principle to solve the problem with our current cognitive faculties (‘mysterianism’).
How Not to Solve the Mind‐Body Problem
Authors: McGinn Colin
Published: March 2005

Against those who appeal to the necessary a posteriori in responding to the mind-body problem, it is argued that a solution to the problem must take the form of an analytic rather than an empirical identity statement, which is to say that a conceptual rather than an a posteriori reduction of consciousness must be provided. Frege showed that true identity statements need not link synonyms, which disposes of some epistemic objections to physicalism, but Kripke’s recognition that all identity statements are necessary (though some are a posteriori) means that if psychophysical identity statements are contingent, as they appear to be, we have good reason to believe that they are false. It is argued that only a conceptual reduction can remove the need to introduce irreducibly psychic properties if the identity statements that are characteristic of physicalism are to be informative. The consequences of this thesis for our prospects of solving the mind-body problem and its implications for arguments against physicalism are discussed. In particular, it is suggested that the only alternative to property dualism is a conceptually true statement identifying body and mind containing radically innovative concepts of body and mind.