cssi/SciSciGPT-SciSciNet huggingface dataset:
The mutagenic potential of ethylene oxide using the dominant--lethal assay in rats.

Abstract The mutagenicity of ethylene oxide in mammalian germinal cell lines was investigated using the dominant-lethal test in rats. Male rats were exposed to 1000 ppm of ethylene oxide for 4 hr and mated each week to groups of two females for 10 weeks. A significant increase in postimplantational fetal deaths was noted in the test group when compared to the negative control group. This significant increase was noted only during the first 5 weeks of the experiment, corresponding to the residence time of germinal cells exposed to ethylene oxide after their meiotic division. Triethylenemelamine served as the positive control. These results indicate that ethylene oxide is capable of inducing mutagenic changes in rat germinal cells.
Photoluminescence investigation of the carrier recombination processes in ZnO quantum dots and nanocrystals

The carrier recombination processes in ZnO quantum dots ($\ensuremath{\sim}4\phantom{\rule{0.3em}{0ex}}\mathrm{nm}$ in diameter), ZnO nanocrystals ($\ensuremath{\sim}20\phantom{\rule{0.3em}{0ex}}\mathrm{nm}$ in diameter) and bulk ZnO crystal have been studied using photoluminescence (PL) spectroscopy in the temperature range from $8.5\phantom{\rule{0.3em}{0ex}}\text{to}\phantom{\rule{0.3em}{0ex}}300\phantom{\rule{0.3em}{0ex}}\mathrm{K}$. The obtained experimental data suggest that the ultraviolet PL in ZnO quantum dots originates from recombination of the acceptor-bound excitons for all temperatures. In the larger size ZnO nanocrystals, the recombination of the acceptor-bound excitons is the dominant contribution to PL only at low temperature $(Tl150\phantom{\rule{0.3em}{0ex}}\mathrm{K})$. For higher temperatures $(Tg150\phantom{\rule{0.3em}{0ex}}\mathrm{K})$, PL is mostly due to recombination of the donor-bound excitons. Recombination processes in ZnO quantum dots and nanocrystals differ from those in bulk ZnO mainly because of the large surface-to-volume ratio in both types of nanoparticles and, consequently, a large number of acceptor defects near the surface. No strong inhomogeneous broadening has been observed in ultraviolet PL from ZnO quantum dots. Our results shed light on the carrier-recombination processes in ZnO quantum dots and nanocrystals, and can be used for the ZnO nanostructure optimization for the proposed optoelectronic and spintronic applications.
Forest bioenergy feedstock harvesting effects on water supply

Water flowing from forested catchments, both unmanaged and managed, is highly valued in terms of both quantity and quality. Increasing energy production using wood feedstocks produces varying degrees of impacts and thereby raises concerns about environmental impacts on the highly valued water supply resources of forest ecosystems. The term water supply encompasses both key components of water quantity and water quality. Water quantity considers the amount of increases or decreases, timing, consistency, and relative magnitude of water yields. Plant nutrients (anions and cations), fertilizers, herbicides, ash additions, temperature, dissolved oxygen, pH, bacteria, and sediment comprise water quality. Within the life cycle of forest bioenergy, operational activities during stand establishment, midrotation silviculture, harvesting, product transportation, wood storage, energy production, and ash recycling create variable levels of impacts. Disturbance levels associated with bioenergy operations depend on their type, intensity, frequency, duration, timing, area of extent, and the level of best management practices (BMPs) employed for mitigating of soil disturbances. Feedstock growing, stand tending, harvesting, and wood transportation are considered nonpoint source disturbances since they occur over larger landscapes than energy production activities, which are usually localized at power plants. Water-quantity effects of forest bioenergy production are normally associated with vegetation management and related soil disturbances. Water-quality effects mostly occur as a result of soil disturbances during harvesting, the use of intra-rotation silvicultural chemicals (ash, fertilizers, and herbicides), and inter-rotation site preparation for forest regeneration. Using existing practices designed for environmental protection (BMPs), forest bioenergy programs are completely compatible with maintaining high-quality water supplies in forested catchments.
Strained-layer InGaAs-GaAs-AlGaAs photopumped and current injection lasers

The materials growth, materials characterization, device fabrication, device results, and modeling of strained-layer InGaAs-GaAs-AlGaAs photopumped and current injection quantum-well lasers are presented. Experimental and theoretical methods for determining the electronic energy states in pseudomorphic quantum wells are presented and discussed, and design curves for the emission energy of biaxially compressed InGaAs and GaAs are presented as a function of indium composition and quantum well width. Photopumped lasers with thresholds comparable to early lattice-matched AlGaAs-GaAs quantum-well lasers, as well as continuous-wave room temperature strained-layer injection lasers, are demonstrated. The temperature dependence of the current injection devices is good (T/sub 0/=147 K) in marked contrast to photopumped samples. Preliminary life test results indicate that long-lived strained-layer injection lasers may be possible. >
A Comparison of the Pulmonary Inflammatory Potential of Different Components of Yeast Cell Wall

1-->3-Beta-glucan has been associated with pulmonary inflammation induced by exposure to fungal or yeast cell wall dust. 1-->3-Beta-glucan is the major cell wall component of yeast or fungi. However, the yeast cell wall contains several other components besides 1-->3-beta-glucans, such as mannan and chitin. Few studies evaluated the contribution of these other cell wall components to pulmonary inflammation. The present study compares a crude particulate yeast cell wall preparation (zymosan A) to purified yeast glucan, purified yeast glucan mannan, or purified yeast glucan chitin particles for their potency to induce mouse pulmonary inflammation after in vivo exposure. Mannan is the second most abundant polysaccharide in the yeast cell wall, whereas chitin content is a minor component. The results show that pulmonary injury is mediated by both chitin and 1-->3-beta-glucan and to a lesser degree by mannan. There is also evidence that zymosan is more potent than purified 1-->3-beta-glucan alone. Evidence indicates that 1-->3-beta-glucan is the major inflammatory component in yeast and fungal cell walls.
Nice to Know You? Testing Contact, Cultural, and Group Threat Theories of Anti‐Black and Anti‐Hispanic Stereotypes*

Objective. Many racial/ethnic policies in the United States—from desegregation to affirmative action policies—presume that contact improves racial/ethnic relations. Most research, however, tests related theories in isolation from one another and focuses on black-white contact. This article tests contact, cultural, and group threat theories to learn how contact in different interactive settings affects whites' stereotypes of blacks and Hispanics, now the largest minority group in the country. Method. We use multi-level modeling on 2000 General Social Survey data linked to Census 2000 metropolitan statistical area/county-level data. Results. Net of the mixed effects of regional culture and racial/ethnic composition, contact in certain interactive settings ameliorates anti-black and anti-Hispanic stereotypes. Conclusions. Cultural and group threat theories better explain anti-black stereotypes than anti-Hispanic stereotypes, but as contact theory suggests, stereotypes can be overcome with relatively superficial contact under the right conditions. Results provide qualified justification for the preservation of desegregation and affirmative action policies.
Raman spectroscopy of C-irradiated graphite

Highly oriented pyrolytic graphite samples were irradiated with C{sup +} ions at 35 keV in a direction normal to the basal plane and subsequently annealed up to 1373 K. Substantial surface topography changes were observed at fluences of 5 {times} 10{sup 18} ions/m{sup 2} and higher using scanning electron and atomic force microscopies. Intricate networks of surface cracks and ridges developed after high dose implantation. A systematic study of the irradiation effects was conducted using Raman spectroscopy. Microstructural changes in irradiated regions were first detected at a dose of 1 {times} 10{sup 17} ions/m{sup 2} through the appearance of the Raman D-line at {approx}1360 cm{sup {minus}1}. The intensity of this line increases while that of the Raman G-line at 1580 cm{sup {minus}1} decreases as the irradiation dose is increased or the irradiation temperature is decreased. After irradiation at 280K to a fluence of 5 {times} 10{sup 19} ions/m{sup 2} or higher the first order spectrum exhibits one single line at a wavelength intermediate between the D- and G-lines. Damage recovery upon thermal annealing depends not only on the initial damage state but also on the annealing temperature sequence. Samples irradiated to a damage level where two distinct Raman peaks aremore » no longer resolvable exhibited upon direct annealing at a high temperature two distinct Raman lines. By contrast, pre-annealing these highly irradiated specimens at lower temperatures produced less pronounced changes in the Raman spectra. Pre-annealing appears to stabilize damage structures that are more resistant to high-temperature annealing than those induced by irradiation.« less
A Faith-Based Physical Activity Intervention for Latinos: Outcomes and Lessons

Abstract Purpose. To develop, implement, and evaluate a pilot faith-based physical activity (PA) intervention for Latinos. Design. Randomized trial, with two churches receiving the intervention and one church serving as a comparison group. Setting. Three Catholic churches near Manhattan, Kansas. Subjects. A subsample of the congregation from the intervention churches (n = 24) and comparison church (n = 23) volunteered to take part in the assessment. Intervention. Culturally and spiritually relevant education materials and activities were developed promoting the health benefits of PA. Educational materials included flyers, bulletin inserts, and posters. An 8-week team based walking contest promoted social support for PA. A health “fiesta” provided hands-on educational opportunities for PA. Measures. Organizational and individual process evaluation outcomes were assessed at baseline and 6 months. Interviews with church contacts at 6 months documented successes and struggles with implementation. Individual-l...
The river—An unresolved obstacle

Abstract The paper discusses the problems associated with the operation of vehicles in and near waterways. The problem will be better understood when world-wide river survey data become available. However even in areas where such data is available amphibious and wading craft often encounter impassable banks. This indicates that dramatic improvements in vehicle egress capabilities are required.
Repair of Fractures of the Distal Aspect of the Radius in Two Horses

Fractures of the distal radius in two horses were repaired by open reduction and interfragmentary compression using screws placed in a lag fashion. One horse had a complete oblique fracture of the medial aspect of the epiphysis of the distal radius and was sound for riding 32 months after surgery. The other horse had an open spiral comminuted fracture with medial displacement of the distal radial fragment. Laminitis developed in the contralateral limb and this horse was euthanatized 5 weeks after surgery. ©Copyright 1994 by The American College of Veterinary Surgeons
The medical necessity of adequate pain management

The experience of pain is not a benign one. This article reviews evidence that painful experiences, including those associated with surgery, result in a perturbation of the neuroendocrine system, leading to immune suppression and the promotion of pathological processes that are normally resisted by the immune system, such as infection and cancer. Evidence that natural killer (NK) cells control the development of metastasis provides a link between immune function and health outcomes. Using an NK-sensitive tumor model in rats, it was recently shown that the pre- and postoperative administration of an analgesic dose of morphine attenuated the observed surgery-induced increase in metastasis, suggesting that pain relief enabled the host to resist this life-threatening consequence of surgery. Further, other studies have shown that whereas rats become rapidly tolerant to the immune-suppressive and tumor-enhancing effects of morphine, no such tolerance develops to daily exposure to painful footshock stress. Taken together, these findings affirm both the benefits and relative safety of morphine contrasted with the pathogenic nature of pain in this context, thus suggesting that the adequate management of pain must become a vital aspect of health care.
A bimodal lognormal model of the distribution of strength of carbon fibres: effects of electrodeposition of titanium di (dioctyl pyrophosphate) oxyacetate

The tensile strength distribution of Fortafil-3 carbon fibres of circular cross-section has been investigated at different gauge lengths. The unimodal Weibull, unimodal lognormal and bimodal lognormal models were tested. Estimating the model parameters by the method of maximum likelihood, and testing each model by the Kolmogorov-Smirnov goodness-of-fit statistic at prescribed levels of significance, it is found that the data for untreated unsized fibres fit a bimodal lognormal model best. The proportions of the low and high strength populations,p andq, respectively, did not show any well-defined trend with gauge length and had average values close to 0.5. But the lognormal mean for each population showed an increasing trend with decreasing gauge length. It is inferred thatp andq are, respectively, related to the presence of surface flaws and internal defects, both of which probably have the same structural origin. After electrodeposition of titanium di (dioctyl pyrophosphate) oxyacetate (TDPO), the fibre strength was still best approximated by a bimodal lognormal distribution. But the weighting factorp for the weak population was reduced markedly, with a corresponding increase ofq, indicating the healing of surface flaws during electrodeposition of a protective layer of TDPO. Furthermore, in contrast to the observations with untreated fibres, the lognormal means for both the low and high strength populations of the electrocoated fibres were essentially unchanged with gauge length. Changes were also indicated in the number and severity of surface flaws, caused by concurrent electrochemical processes.
Hardware-in-the-loop evaluation of traffic signal systems

Vendors of modern traffic control equipment implement many unique algorithms designed to move traffic more efficiently. However, because of either the difficulty in modeling or the proprietary nature of the algorithms, many of these vendor specific algorithms can not be adequately evaluated using general purpose macroscopic or microscopic simulation models. This paper describes a procedure for incorporating actual traffic signal control equipment into a microscopic simulation to provide a rigorous of algorithms embedded in traffic devices. This procedure can be used to evaluate systems as diverse as SCOOT, SCATS or closed loop traffic responsive systems.
HREM study of 45° [100] quasiperiodic grain boundary in aluminum

The structural study of grain boundaries is central to a better understanding of many physical properties of polycrystalline materials. The current body of knowledge on interface structures is almost entirely accumulated from grain boundaries and interfaces with periodic structure. The vast majority of grain boundaries in polycrystalline materials are more general and possess complex atomic structure. Owing to the complex structure of these boundaries, it seems desirable initially to perform structural investigations on boundaries intermediate to periodic and complex general boundaries. Quasiperiodic grain boundaries do not possess translational periodicity, but have some degree of structural order. Thus, they can be considered as a bridge between periodic and general boundaries, and they offer an opportunity to study structures that may be prototypes of more complex boundaries. The structure of quasiperiodic boundaries can be characterized within the framework of the crystallography of quasicrystals. So far, only a few structural studies of quasiperiodic boundaries have been reported. This paper focuses on quasiperiodic boundaries and presents for the first time an HREM study of a 45{degree} [100] twist quasiperiodic grain boundary.
Moiré fringe analysis of small precipitates in melt-spun titanium-silicon alloys.

Oxygen-contaminated, melt-spun, binary Ti-Si alloys have been examined by using transmission electron microscopy. The microstructure of alloys in the range of 4 to 10% Si (by weight) are cellular and consist primarily of alpha-Ti and the silicide Ti5Si3. Contained only within the Ti5Si3 regions are small, approximately spherical particles which are less than or equal to 10 nm in diameter. Due to their small size, the crystal structure of these particles could not be determined by using conventional diffraction techniques such as Selected Area or Convergent Beam Diffraction. By conducting a number of tilting experiments and observing the moire fringe patterns produced when various matrix Ti5Si3 planes were used to image the sample, the crystal structure of the particles and the orientation relationship which exists between them and the matrix were deduced. The unknown particles, termed the Z phase, were found to be hexagonal with slightly different lattice parameters from the matrix Ti5Si3. Their relationship with the matrix was such that they appeared to be totally coherent. This may indicate that Z is an oxide based on the intermetallic Ti5Si3.
Remote hot spots mediate protein substrate recognition for the Cdc25 phosphatase

Cdc25B is a phosphatase that catalyzes the dephosphorylation and activation of the cyclin-dependent kinases, thus driving cell cycle progression. We have identified two residues, R488 and Y497, located >20 A from the active site, that mediate protein substrate recognition without affecting activity toward small-molecule substrates. Injection of Cdc25B wild-type but not the R488L or Y497A variants induces germinal vesicle breakdown and cyclin-dependent kinase activation in Xenopus oocytes. The conditional knockout of the cdc25 homolog (mih1) in Saccharomyces cerevisiae can be complemented by the wild type but not by the hot spot variants, indicating that protein substrate recognition by the Cdc25 phosphatases is an essential and evolutionarily conserved feature.
Magnetic dynamics with spin-transfer torques near the Curie temperature

We use atomistic, stochastic Landau-Lifshitz-Slonczewski simulations to study the interaction between large thermal fluctuations and spin-transfer torques in the magnetic layers of spin valves. At temperatures near the Curie temperature ${T}_{\text{C}}$, spin currents measurably change the size of the magnetization (i.e., there is a longitudinal spin-transfer effect). The change in magnetization of the free magnetic layer in a spin valve modifies the temperature dependence of the applied field-applied current phase diagram for temperatures near ${T}_{\text{C}}$. These atomistic simulations can be accurately described by a Landau-Lifshitz-$\text{Bloch}+\text{Slonczewski}$ equation, which is a thermally averaged mean-field theory. We use this equation to find the stability phase diagram of a ferromagnetic layer near its Curie temperature. Both the simulation and the mean-field theory show that a longitudinal spin-transfer effect can be a substantial fraction of the magnetization close to ${T}_{\text{C}}$.
Dimensions of impulsivity are associated with poor spatial working memory performance in monkeys.

Impulsive behavior and novelty seeking are dimensions of temperament that are behavioral determinants of risk for attention deficit/hyperactivity disorder and its neurocognitive endophenotypes, and variation in the dopamine D4 receptor gene (DRD4) explains at least a portion of the variance in the traits. To further characterize the dimensional phenotype associated with impulsiveness, adolescent male monkeys were evaluated using ecologically valid tests of impulsive approach and aggression in response to social or nonsocial stimuli; subsequently, a delayed response task was implemented to assess spatial working memory performance. Subjects were selected into this study based on their response to the social challenge task or by DRD4 genotype, resulting in three groups: low-impulsivity/common DRD4 allele, high-impulsivity/common DRD4 allele, or rare DRD4 allele. All animals acquired the delayed response task and could perform at near ceiling levels when a ∼0 s delay version was imposed, but as delays were lengthened, high-impulsive animals, regardless of DRD4 genotype, made fewer correct responses than did low-impulsive subjects; an inverse relationship existed for working memory and impulsivity. Notably, impulsive behavior evoked by social and nonsocial stimuli explained overlapping and independent portions of the variance in working memory performance. CSF levels of monoamine metabolites did not significantly differentiate the high- and low-impulsive animals, although monkeys carrying the DRD4 rare allele tended to exhibit higher monoamine turnover. These data indicate that dimensions of impulsivity may impact on working memory performance in qualitatively similar ways but through different mechanisms.
Molecular mechanism and structure of the Saccharomyces cerevisiae iron regulator Aft2.

The paralogous iron-responsive transcription factors Aft1 and Aft2 (activators of ferrous transport) regulate iron homeostasis in Saccharomyces cerevisiae by activating expression of iron-uptake and -transport genes when intracellular iron is low. We present the previously unidentified crystal structure of Aft2 bound to DNA that reveals the mechanism of DNA recognition via specific interactions of the iron-responsive element with a Zn2+-containing WRKY-GCM1 domain in Aft2. We also show that two Aft2 monomers bind a [2Fe-2S] cluster (or Fe2+) through a Cys-Asp-Cys motif, leading to dimerization of Aft2 and decreased DNA-binding affinity. Furthermore, we demonstrate that the [2Fe-2S]-bridged heterodimer formed between glutaredoxin-3 and the BolA-like protein Fe repressor of activation-2 transfers a [2Fe-2S] cluster to Aft2 that facilitates Aft2 dimerization. Previous in vivo findings strongly support the [2Fe-2S] cluster-induced dimerization model; however, given the available evidence, Fe2+-induced Aft2 dimerization cannot be completely ruled out as an alternative Aft2 inhibition mechanism. Taken together, these data provide insight into the molecular mechanism for iron-dependent transcriptional regulation of Aft2 and highlight the key role of Fe-S clusters as cellular iron signals.
Molecular Beam Investigation of Rotational Transitions. II. The Rotational Levels of KBr and Their Hyperfine Structure

The molecular beam electrical resonance method, which has heretofore been confined to the study of transitions between the $m=0$ and $m=\ifmmode\pm\else\textpm\fi{}1$ states of diatomic polar molecules in the state $J=1$, has been extended to the study of rotational transitions from $J=0$ to $J=1$. The inhomogeneous electric fields together with a stop wire are so arranged that molecules in the state $J=0$ are selectively refocused on the detector. A transition to the state $J=1$, under the influence of the applied rf field, is observed by a reduction in beam intensity at the detector. The spectra obtained in this way yield more information than with the older method. The hyperfine structure of the state $J=1$ of the molecules ${\mathrm{K}}^{39}$${\mathrm{Cl}}^{35}$, ${\mathrm{K}}^{39}$${\mathrm{Cl}}^{37}$, and ${\mathrm{K}}^{41}$${\mathrm{Cl}}^{35}$ has been investigated at zero field for several vibrational states. The molecular constants obtained for these molecules are: The structure of the $J=1$ state was attributable to a nuclear quadrupole interaction for each nucleus. The variations of ${(\mathrm{eqQ})}_{\mathrm{K}}$ and ${(\mathrm{eqQ})}_{\mathrm{Cl}}$ with vibrational state are The ratios of the quadrupole moments of the potassium isotopes is $\frac{{Q}_{{\mathrm{K}}^{41}}}{{Q}_{{\mathrm{K}}^{39}}}=1.220\ifmmode\pm\else\textpm\fi{}0.002.$ From observation of line shifts in a weak electric field, the molecular dipole moment was determined in two vibrational states. For $v=0$, $\ensuremath{\mu}=10.48\ifmmode\pm\else\textpm\fi{}0.05$ Debye, and for $v=2$, $\ensuremath{\mu}=10.69\ifmmode\pm\else\textpm\fi{}0.05$ Debye. The ratio of the dipole moments is 1.020\ifmmode\pm\else\textpm\fi{}0.004. The mass ratios of the chlorine and potassium isotopes calculated from the molecular constants are $\frac{{\mathrm{Cl}}^{35}}{{\mathrm{Cl}}^{37}}=0.9459803\ifmmode\pm\else\textpm\fi{}0.0000015 \mathrm{and} \frac{{\mathrm{K}}^{39}}{{\mathrm{K}}^{41}}=0.9512189\ifmmode\pm\else\textpm\fi{}0.0000015.$
SUM RULE FOR OPTICAL NUCLEAR REACTIONS

Abstract The direct or optical component of nuclear reacyions is computed essentially by a first-order perturbation procedure. It should thus be subject to simple sum rules. One such rule is applied to elastic and inelastic α-particle scattering on Ne 20 , where it is in qualitative accord with the observed smoothing out of fluctuations in the summed angular distributions.
Kinetics of retrovirus mediated gene transfer: The importance of intracellular half-life of retroviruses

Gene therapy is a new therapeutic modality that holds vast potential for the treatment of genetic disorders. Retroviruses are used as a vehicle for the transfer of genes into mammalian cells. The process of gene transfer has been shown to depend on the cell cycle status of target cells. We constructed a mathematical model that integrates the kinetics of gene transfer with cell cycle kinetics. We define three cell populations: uninfected cells, cells with the virus in their cytoplasm, but not integrated, and infected cells, in which the viral DNA has integrated in their genome. Our model predicts that the stability of the viral particles after internalization in the cellular cytoplasm, limits the process of gene transfer. Intracellular viral half-life also limits the usefulness of synchronization experiments, used to detect cell cycle dependence of the gene transfer process. We use the predictions of our model to propose a new experimental method for the detection of cell cycle dependence of retrovirus mediated gene transfer. It is based on the maturity distributions of the infected cells, and it is independent of viral intracellular stability. Despite the importance of the viral intracellular half-life this quantity still remains unknown. An extended version of the model is used to simulate a novel experimental method that measures the intracellular retroviral half-life. Analytical solutions of a simplified model confirm our numerical results and reveal the key dimensionless groups that characterize the process of gene transfer. Knowledge of the intracellular half-life of retroviral vectors is of particular importance for the design of new vectors, especially for slowly growing target cells, such as the stem cells of the hematopoietic system.
Comparative study of electropolymerization versus adsorption of tyrosine and the decyl ester of tyrosine on platinum electrodes

Abstract We compared adsorption versus electropolymerization via cyclic voltammetry (CV) of tyrosine, an amino acid, to that of the decyl ester of d -tyrosine (DEDT), on Pt electrodes. DEDT is an amphiphilic compound, capable of self-assembly into long rod like or tubular aggregate structures. Tyrosine and DEDT differ fundamentally in their interactions with the Pt electrode, affecting their electropolymerization behavior. The DEDT exhibits a significant level of adsorption to the Pt surface, resisting desorption via washing to allow a significant peak current I p to be measured. At concentrations 30 times higher than DEDT, tyrosine exhibits no equivalent behavior. The sweep rate dependence of I p measured during the first CV cycle of film formation for the two species indicates very different behavior as well. Tyrosine has a square root dependence indicating a diffusion limiting mechanism, while DEDT has a linear sweep rate dependence indicating that it is a surface confined species and follows an adsorption limiting mechanism. Electrochemical quartz crystal microbalance (EQCM) studies show that in the absence of an applied potential, tyrosine does not adsorb to the Pt electrode since no Δ f shift is observed. On the other hand, DEDT does adsorb to a significant extent, displaying a sizable Δ f shift. When these same samples are then electropolymerized, tyrosine forms an electropolymerized film stepwise with each potential cycling step, while DEDT, already adsorbed to the Pt, exhibits no net mass gain for any of the potential cycles. Therefore, little electropolymerization of DEDT can take place in the presence of a significant adsorption level of this monomer. We ascribe these differences between tyrosine and DEDT largely to the presence of the decyl chain on DEDT, which can bind hydrophobically to the Pt surface and allow DEDT monomers to self-assemble with one another.
THE PITTING CORROSION OF ZIRCONIUM AND ZIRCONIUM-NIOBIUM ALLOYS IN SULPHATE SOLUTIONS CONTAINING CHLORIDES AT 300—373 K

Abstract The effect of temperature on the pitting corrosion of zirconium immersed in sulphate solutions containing chloride was investigated using the scratch method at 300–373 K. The scratch method measures the re-passivation potential Er, representing the potential below which pits re-passivate. In potentiokinetic measurements, the re-passivation potentials were always more active than the pit nucleation potential Ep above which pits nucleate. Pit nucleation potentials were measured by potentiokinetic and potentiostatic methods. Temperature does not affect Er when zirconium is immersed in 1 N KCl, but affects Er slightly when SO42- ions are present in the solution. At 80 °C (353 K), Er decreases linearly with increasing Cl- ion content, but increases noticeably when SO42- ions are present. The Er values of zirconium and Zr-Nb alloys are approximately equivalent when immersed in a 1 N KCl solution.
High efficiency quasi-phasematched frequency doubling waveguides in KTiOPO4 fabricated by electric field poling

Waveguides for quasi-phasematched frequency doubling were fabricated using an applied electric field to produce periodic poling and ion-exchange to produce channel waveguides. A blue output power of 12 mW was achieved with 146 mW of infrared light in a 3.6 mm-long waveguide.
The effects of buccal corridor spaces and arch form on smile esthetics.

Purpose: An attractive, well-balanced smile is a paramount treatment objective of modern orthodontic therapy. The purpose of this study was to determine the effects of buccal corridor spaces (BCS) and arch form on smile esthetics as perceived by laypeople, general dentists, and orthodontists. Material: Photographs of 20 women treated by 2 orthodontists were collected: 1 group had narrow tapered or tapered arch forms, and the other had normal to broad arch forms. Photographs of 10 untreated women served as a control sample. All photographs showed the subjects smiling. The photographs were digitized and evaluated for BCS. Then, photographs with BCS were altered to eliminate the dark triangular areas, and those without BCS were altered by the addition of dark triangular areas at the lateral aspects of the smile. The altered photographs were randomized into a survey with the 30 original photographs. Three groups of raters (dentists, orthodontists, and laypeople) used a visual analogue scale to rate the photographs. Results: There was no significant difference in smile scores related to BCS for all samples and for all viewers. Dentists rated broader arch forms as more esthetic than untreated arch forms. Orthodontists rated broader arch forms as more esthetic than narrow tapered arch forms and untreated arch forms. Lay people showed no preference of arch form. Conclusions: This study demonstrates that the presence of BCS does not influence smile esthetics. However, there are differences in how dentists, orthodontists, and laypeople evaluate smiles and in what arch form each group prefers.
Closure of Scalp and Forehead Defects Using External Tissue Expander

Objective To describe the novel use of an external tissue expander in the reconstruction of scalp and forehead defects. Methods A prospective review was performed on 7 patients who underwent extirpation of head and neck malignant neoplasms resulting in scalp and forehead defects. Reconstruction was performed using an external tissue expander device. Patient clinical factors, defect size, and photographs were collected. Results Seven patients had large scalp and forehead defects ranging in greatest dimension from 5.0 ×4.0 to 8.0 ×7.0 cm. The external tissue expander was in place for 6 to 14 days, reducing the defect sizes by 50% to 99%. At the time of device removal, primary closure was achieved in 5 patients. One patient required bilateral advancement rotation flaps, and 1 patient healed by second intention. One patient with a history of scalp irradiation and diabetes had partial skin loss after device removal and required reconstruction with a latissimus dorsi myocutaneous free flap. There were no other postoperative complications, wound breakdown, or device failures. Conclusion External tissue expansion is a safe and effective technique for closing large scalp and forehead defects that would otherwise require skin grafting or free flap reconstruction.
Negotiating health care: the experiences of young lesbian and bisexual women

An emerging body of research shows that lesbians and bisexual women face multiple barriers to health care and are in a vulnerable position when accessing care and interacting with health care providers. Young women's experiences have been only marginally researched, however. This article describes findings from a qualitative study that explored the health-related experiences of eight young lesbian and bisexual women ages 18-21 in San Francisco, California, USA, and focuses on how participants negotiated the health care interaction. The negotiations highlight (1) the agency exercised by these young women; (2) the impact of health care providers on young lesbian and bisexual women's access to and utilization of medical care; and (3) the ways the health care interaction reflects larger power dynamics in society.
(156) Differences in regional gray-matter density between fibromyalgia patients and controls: A voxel-based morphometry study

Fibromyalgia (FM) is thought to involve abnormalities in central pain processing, and recent studies on small numbers of subjects have suggested reductions in gray-matter density (GMD) in FM patients. Our objective was to search for regional differences in GMD between FM patients and controls, and to determine whether regional GMD is correlated with pressure-pain threshold and symptoms of depression or anxiety. We used a case-control design involving 51 patients and 51 age-matched healthy controls (4% and 10% male, respectively). Our primary outcome measure was regional GMD as estimated by voxelbased morphometry on T1-weighted MRI brain images (1.5mm slice thickness, 3T GE scanner). We excluded scans containing structural lesions or artifacts. We performed a region-of-interest (ROI) search using ROIs based on findings from previous studies, and extracted signal intensities from these ROIs for use in bivariate correlations with pressurepain threshold (Multiple Random Staircase method), depression (Center for Epidemiological Studies Depression scale) and anxiety (State-Trait Personality Inventory, Trait Anxiety subscale). ROI analysis revealed decreased GMD in the left anterior insula (pFWE 0.051) and right anterior cingulate cortex (pFWE 0.055) in patients compared to controls. No other ROIs showed significant GMD differences between groups. In exploratory analyses we investigated a previously-reported contrast between left and right insula with respect to pain and emotional processing. In patients, the signal intensity difference between left and right insula correlated significantly with depression scores (r -.374, p .01). In controls, the signal intensity difference between left and right posterior insula correlated significantly with medium pressure-pain threshold (r .364, p .009). This is the largest study to date comparing regional GMD between FM patients and age-matched controls. Subjects with FM seem to exhibit a reduction in GMD in the left anterior insula and right anterior cingulate cortex; decreased density in the left insula relative to right insula seems to correlate with depression in FM.
Ectodermal Placodes Contributions to the Development of the Vertebrate Head

Neurogenic placodes are focal ectodermal thickenings that give rise to the sensory neurons, and in some cases, the receptor cells of vertebrate sensory systems. There are no markers for the identification of undifferentiated placodal epithelia, but derivatives of the nasal placode, for example, are characterized by unique production of GnRH and olfactory marker protein. Placode morphogenesis occurs by invagination and/or delamination to form sensory epithelia, sensory neuroblasts and in some cases, migratory receptor primordia ( e g , lateral line receptors). Specification of neurogenic placodes and pattern formation of their derivatives has been a subject of study for over eighty years, and is still not well understood, but, several genes have been implicated in pattern formation in the derivatives of the otic placode. The lateral line system is unique among placode-derived sensory systems in vertebrates in that it is only present in anamniotes, it is derived from multiple placodes, has an extensive migratory component and gives rise to two classes of sensory receptor organs that mediate two distinct sensory modalities (mechanoreception and electroreception) which share nervous innervation, but project independently to the hindbrain. Nasal and otic placodes, like other epithelia are capable of inducing skeletogenesis in neural crest and mesodermal mesenchyme and thus via induction contribute to the morphogenesis of the vertebrate skull. The long-standing hypothesis that neuromast receptors induce the formation of the lateral line canals associated with the dermal bones on the heads of fishes remains untested, but it is evident that lateral line bones are composed of both dermal bone and lateral line canal bone and may be subject to two discrete and potentially conflicting sets of functional demands in the heads of fishes.
Histopathology of Bone Marrow

As a major hematopoietic and lymphoid organ, morphological evaluation of the bone marrow is an important component of toxicity or safety assessment studies. While definitive characterization of bone marrow lesions often requires cytological aspirates or smears, assessment of histological bone marrow sections provides information regarding tissue architecture and hematopoietic status that is relevant for the detection of direct or indirect responses to chemical exposure. A variety of lesions have been observed in bone marrow. For example, lesions involving disturbances in growth, degenerative changes, inflammatory changes and neoplasia have been described. Lesions identified in hematoxylin and eosin-stained sections typically represent changes in the hematopoietic cell lineage and/or stromal cells since definitive identification of lymphoid cells is difficult except in cases of lymphoma. This review provides a descriptive and pictorial representation of a wide range of bone marrow lesions. Since large animal-to-animal variation may exist and there can be collection site- and age-related differences, it is imperative that the pathologist reviews all potential treatment-related findings against appropriate concurrent controls.
New fluorinated oxazoline block copolymer lowers the adhesion of platelets on polyurethane surfaces

We have prepared an amphiphilic oxazoline block copolymer of hydrophilic poly(2-methyl-2-oxazoline) and hydrophobic poly[2-(2-perfluorooctyl)ethyl-2-oxazoline] chains. By controlling the length and composition of polymer chains, we found that this fluorinated block copolymer can be readily dissolved in water. Furthermore, we can achieve a stable surface coating of the fluorinated block copolymer by dissolving the copolymer in water, then coating the aqueous copolymer solution onto surfaces of nonwater-soluble polymers. We have found that the polyetherurethane (PEU) coated by block copolymer has a different surface chemistry and biological reactivity than the uncoated PEU
Epigenetic reprogramming of cloned animals.

CLONED ANIMALS have been generated from somatic cells in several species in recent years (Wilmut et al., 1997; Well et al., 1999; Polejaeva et al., 2000). Cloning, however, is very inefficient and characterized by high embryonic lethality associated with severe abnormalities of cloned fetuses and placentas in rodents and ruminants. Interestingly, fetal and placental abnormalities have somewhat common features amongst hundreds of cloned animals, irrespective of substantial differences in pregnancy physiology and placentation (Wakayama and Yanagimachi, 1999; Hill et al., 1999; Eggan et al., 2001; Chavatte-Palmer et al., 2002). The vast majority of cloned animals affected by severe alterations also have in common a somatic cell origin, from either adult or fetal tissues in mouse and domestic species. Erasure of differentiation memory from somatic cells used as donor nuclei to an embryonic-like totipotent state requires epigenetic reprogramming. Faulty epigenetic reprogramming is highlighted as the major cause of developmental failure and abnormal phenotypes in cloned animals. The epigenetic, and not genetic, nature of alterations in cloned animals is supported by the fact that cloned animals are able to reproduce and generate normal progeny (Tamashiro et al., 2002). Moreover, cloned embryos and fetuses are conclusively affected by epigenetic alterations detected at both genome-wide (Dean et al., 2001; Cezar et al., 2003) and gene-specific levels (Humpherys et al., 2001). The current review intends to provide a comprehensive understanding of epigenetics and how it relates to mammalian development. Additionally, faulty epigenetic reprogramming will be addressed as a potential determinant of developmental failure and phenotypical abnormalities that are widely prevalent in cloned animals.
Value Judgments and the True Self

The belief that individuals have a "true self" plays an important role in many areas of psychology as well as everyday life. The present studies demonstrate that people have a general tendency to conclude that the true self is fundamentally good--that is, that deep inside every individual, there is something motivating him or her to behave in ways that are virtuous. Study 1 finds that observers are more likely to see a person's true self reflected in behaviors they deem to be morally good than in behaviors they deem to be bad. Study 2 replicates this effect and demonstrates observers' own moral values influence what they judge to be another person's true self. Finally, Study 3 finds that this normative view of the true self is independent of the particular type of mental state (beliefs vs. feelings) that is seen as responsible for an agent's behavior.
Robustness of Taylor’s law under spatial hierarchical groupings of forest tree samples

Testing how well Taylor’s law (TL) describes spatial variation of the population density of a species requires grouping sampling areas (patches of habitat) into blocks so that a mean and a variance of the population density can be calculated over the patches in each block. The relationship between specific groupings and TL remains largely unknown. Here, using tree counts from a deciduous forest, we studied the effect of four biological methods of grouping sampling areas into blocks on the form and parameters of TL. Regardless of the method of grouping, the species-specific basal area densities obeyed TL, and the estimated slopes were not significantly different from one grouping method to another. Surprisingly, TL remained valid when four kinds of randomizations were performed to the biological groupings and tree census. These randomizations randomly assigned sampling areas to blocks, and/or randomized the species composition within or across sampling areas. We found that the form of TL was robust to different grouping methods and species randomizations, but its parameter values depended significantly on species compositions at sampling areas.
Structural Diversity and Close Interracial Relationships in College

Recent legal and political actions have challenged the use of race-conscious college admissions policies. Earlier research offers mixed evidence about the link between an institution’s racial/ethnic composition (i.e., structural diversity) and the formation of close interracial relationships, so the present study examines this topic directly for several racial/ethnic groups. Within a large longitudinal data set, structural diversity is positively related to having close interracial friendships and a different-race romantic partner for White students, and no main effects of structural diversity are apparent for Black and Hispanic students. Moreover, structural diversity has increasingly positive effects at higher levels of campus diversity.
Association of brain atrophy and vascular white matter lesions with CERAD score in Alzheimer's disease

association with right-sided hippocampal atrophy of the subiculum and the CA1 area in the full PD sample (p1⁄40.043) and trend-level association in PDCN only (0.076) [Figure 1]. Conclusions: Impaired performance on delayed free recall and recognition is associated with bilateral hippocampal atrophy in newly diagnosed drug-Na€ive PD patients These findings are in agreement with our hypotheses. At time of diagnosis PD subjects already show structural changes of the hippocampus which are associated with memory performance.
Low density parity check (LDPC) codes for optical data storage

Low-density parity check (LDPC codes, first introduced by Gallager (1962), are error-correcting codes based on very sparse parity check matrices. Recently, in the wake of excellent performance of turbo codes, LDPC codes were rediscovered as another category of random codes approaching the Shannon capacity limit with practical decoding complexity. Extensive investigation of the applications of turbo codes and LDPC codes for data storage channels has been reported. While LDPC codes can be iteratively decoded using the sum-product algorithm with moderate complexity, the memory required to specify the nonzero elements in the random parity check matrix can be a major challenge for hardware implementation. Construction of good LDPC codes with structure is particularly desired in data storage channels to facilitate low complexity implementation. We address this issue by introducing a class of low complexity structured LDPC codes which are useful for optical data storage.