cssi/SciSciGPT-SciSciNet huggingface dataset:
Atomistic simulations on the tensile debonding of an aluminum-silicon interface

Abstract In this paper we present Modified Embedded Atom Method (MEAM) simulations of the deformation and fracture characteristics of an incoherent interface between pure FCC aluminum and diamond cubic silicon. As a first approximation, the study only considers the normal tensile separation of a [100] interface with the principal crystallographic axis of the aluminum and the silicon aligned. The MEAM results show that the relaxed interface possesses a rippled structure, instead of a planar atomic interface, and such ripples act as local stress concentrators and initiation sites for interfacial failure. The stress–strain (traction–displacement) response of aluminum and silicon blocks attached at an interface depends on the distance from the interface that the boundary conditions are applied, i.e. the size of the atomic blocks, and the location of the measured opening displacement. Point vacancy defects near the interface are found to decrease the maximum normal tensile stress that the interface can support at a rate almost linearly proportional to the number fraction of the dispersed defects. A crack-like vacancy defect in the bulk aluminum or silicon must reach an area fraction (projected to the surface normal to the tensile axis) of about 50 or 30%, respectively, in order to shift the failure from the interface to the bulk materials. It is further demonstrated that the present results are consistent with continuum-based traction separation laws, provided that the opening displacement is measured near the physical boundary of the deforming cohesive zone (±10 A from the boundary of the Al–Si interface). As the opening displacements are measured farther from the interface, the traction–displacement response approaches that of classical linear elastic fracture mechanics.
Will a continuous GPS array for L.A. help earthquake hazard assessment

The striking landscapes and hospitable climate of Southern California are home to more than 20 million people and vital elements of the nation's economy. Unfortunately, the region is also laced with many active faults that can produce strong earthquakes. Scientists from several institutions are pursuing a new approach to studying earthquake hazards in a high-risk metropolitan area. The Southern California Integrated GPS Network (SCIGN) is currently an array of about 40 Global Positioning System (GPS) stations distributed throughout the greater Los Angeles metropolitan region. There have been informal discussions about expanding the array to 250 stations, and formal proposals have been submitted to begin this expansion. To achieve high precision, the sites will be carefully monumented, and all the GPS receivers will operate continuously. The goals of the array are to provide an accurate and detailed velocity field from which to identify the deformation from known faults, test current models of the geologic structure, and make better estimates of the seismic potential in the populous parts of southern California.
Estimates of dispersion from clustered-drifter deployments on the southern flank of Georges Bank

Abstract Data from 16 clustered-drifter deployments are used to examine horizontal dispersion on the southern flank of Georges Bank. The spreading rates of all clusters have an average of 1.6 km d −1 with a standard deviation of 1.8 km d −1 . Both “effective” and “apparent” diffusivities are calculated for each cluster. Their ranges (e.g. −54 to+757 m 2 s −1 for effective diffusivity) are related to differences in cluster size and proximity to the tidal mixing front. Cross-bank convergence is documented for nearly 40% of the clusters. This occurs especially for clusters with centroids within 10 km of the tidal mixing front location, as deduced from conductivity, temperature, and depth transects (CTD) conducted concurrently with the cluster deployments. Estimates of turbulent dispersion (distinct from shear effects) are derived by the method of A. Okubo and C.C. Ebbysmeyer (1976. Determination of vorticity, divergence, and deformation rates from analysis of drogue observations. Deep-Sea Research 23, 349–352). The results reveal that the effects of horizontal shear are important in spreading of larger drifter clusters. Often the impact of shear is evidenced by the track of a lone drifter that separates from a cluster as it is entrained into the current of the shelf-edge front or the tidal mixing front. Cluster dispersion is time dependent as evidenced by a significant modulation of cluster size at the M 2 tidal frequency. This modulation is due to the spatial variation of tidal currents over the southern flank of Georges Bank and is closely reproduced by immersing drifter clusters into the flow field of a Georges Bank tidal model.
Energy transfer from a surface-bound arene to the gold core in ω-fluorenyl-alkane-1-thiolate monolayer-protected gold clusters

9-(9-Fluorenyl)-nonane-1-thiolate and 12-(9-fluorenyl)-dodecane-1-thiolate (fluorenyl-alkane-1-thiolates) monolayer-protected gold clusters (Au-MPCs) have been prepared by place exchange of fluorenyl-alkane-1-thiol with alkane-1-thiolate Au-MPCs. The structures of these composites were established by TEM, elemental analysis, and 1 H NMR spectroscopy. Changes in optical and physical properties caused by attachment of the fluorenyl groups to the gold nanoparticles were studied by absorption, Fourier transform infrared, and fluorescence spectroscopies. Emission from the end-attached fluorenyl groups is substantially quenched upon attachment to a gold cluster so that less than 5% of emission intensity from an optically matched solution of the analogous freely dissolved fluorene and alkane-1-thiolate Au-MPCs is retained in the fluorenyl-alkane-1-thiolate Au-MPCs. Nanosecond flash photolysis shows that intersystem crossing (from the fluorenyl singlet to the corresponding triplet) was suppressed because energy transfer was much faster. No direct evidence of electron transfer from the excited fluorenyl group to the gold cluster could be observed, implying that electronic coupling through energy transfer accounts for most of the observed emission quenching and suppressed intersystem crossing.
State-dependent Riccati equation for control of aeroelastic flutter

Feedback control design for suppression of flutter in an aeroelastic system is studied. Feedback control laws based on the state-dependent Riccati equation are derived. Two control laws are studied: one formulation uses an observer to estimate the states after which it uses the estimated states to generate feedback law; the other formulation uses partial observation to directly generate the control law.
Collagen Polymorphism: Characterization of Molecules with the Chain Composition [α1(III)]3 in Human Tissues

Collagen moleculess with the chain comizposition [alpha1(III)](3), have been isolated from pepsin-solubilized collagen of dermis, aorta, and leiomlyoma of the uterus by differential salt precipitation. On denaturation, approximately 90 percent of this collagen is recovered as a gamma component (300,000 daltons). Reduction and alkylation of the high-molecular-weight component yields alpha1(III) chains (95,000 daltons). In addition to containing cysteine, alpha1(III) chains exhibit several other compositional differences when compared to alpha1(I), alpha1(II), or alpha2 chains from human tissues.
Delayed development in Fischer's pygmy fruit bat, Haplonycteris fischeri, in the Philippines

A long delay in post-implantation embryonic development was detected in Fischer's pygmy fruit bats (palaeotropical fruit bats of the suborder Megachiroptera), the first time such a delay has been demonstrated outside the bat suborder Microchiroptera. Samples of bats were obtained from the Philippines over 5 years, and reproductive tracts were preserved and examined using standard histological techniques. Most parous female pygmy bats were impregnated in June, within a few weeks of parturition, and the embryos underwent superficial implantation at the anterior end of the uterus contralateral to the previously gravid uterus. Shortly thereafter, the rate of embryonic growth slowed tremendously for up to 8 months. During the period of delay, the mean length of the embryoblast increased only from 280 microns to 520 microns. In March of the following year, the developmental rate increased, and the embryos completed development in the next 3 months. The 8-month delay gives these bats a gestation period of 11.5 months, the longest known in bats. Most nulliparous females become pregnant at an age of 3-5 months, and their embryos entered a similar delay that terminated in March or April, after 2-6 months of delay. Males showed signs of fertility throughout the entire year, but testis volume was highest during May, June and July, at about the time when most females become receptive.
Instanton-induced amplitudes in a supersymmetric theory

Abstract We consider the effective lagrangian for multiple self-interaction of matter fields induced by instantons in a weakly coupled SU (2) supersymmetric Yang-Mills theory with one matter flavor. By using the supersymmetric instanton calculus, we come to the surprising conclusion that the interaction induced by instantons in the one instanton sector of the theory is strictly local for scalar particle emission, accompanied by fermion number violation. The contribution of instantons arises only from instantons of zero scale size. The restoration of unitarity in high-energy scattering is thus only possible through multi-instanton-antiinstanton effects.
Methylation perturbations in retroelements within the genome of a Mus interspecific hybrid correlate with double minute chromosome formation.

Abstract A reduction in the DNA modification of cytosine methylation has been linked directly to chromosome rearrangements concomitant with retroelement amplification in several marsupial hybrid genomes. While phenotypes observed for interspecific eutherian hybrids are suggestive of methylation perturbations and retroelement instability, no link between retroelements, DNA methylation, and chromosome instability has yet been identified. Previous studies in eutherian hybrids, however, have been limited to a gross examination of methylation using methylation-sensitive restriction enzyme analysis or focused on single-copy genes and/or have avoided examination of repetitive DNA. Methylation changes and retroelements are proposed as mechanisms for double minute chromosome formation and oncogene amplification, both present in the genome of a Mus hybrid model, thus making it an ideal system to evaluate methylation status more closely. We have used the PCR-based methodologies methylation-sensitive amplicon subtraction (MS-AS) and methylation-sensitive representational difference analysis (MS-RDA) to detect differentially methylated sequences between three complex genomes and to isolate methylation perturbations in a Mus musculus × Mus caroli hybrid. This novel application of MS-AS and MS-RDA resulted in the isolation of differentially methylated retroelements surrounding the locus on Chromosome 10 responsible for double minute chromosome formation within this interspecific eutherian hybrid.
Genital tract colonization with methicillin-resistant staphylococcus aureus (MRSA) is not associated with a high risk for early-onset invasive neonatal infection

CUS AUREUS (MRSA) IS NOT ASSOCIATED WITH A HIGH RISK FOR EARLY-ONSET INVASIVE NEONATAL INFECTION WILLIAM ANDREWS, ROBERT SCHELONKA, SUZANNE CLIVER, MARTHA LYON, KEN WAITES, STEPHEN MOSER, A. STAMM, University of Alabama at Birmingham, Obstetrics/Gynecology, Birmingham, Alabama, University of Alabama at Birmingham, Pediatrics-Neonatology, Birmingham, Alabama, University of Alabama at Birmingham, Pathology, Birmingham, Alabama, University of Alabama at Birmingham, Medicine, Birmingham, Alabama OBJECTIVE: To determine the rate of genital tract colonization with MRSA among pregnant women and assess the association between MRSA colonization and early-onset invasive neonatal infection. STUDY DESIGN: Between July 2003 and June 2006, recto-vaginal screening cultures for group B Streptococcus (GBS) were obtained between 35 and 37 weeks’ gestation. The presence of Staphylococcus aureus and MRSA was determined in these cultures using standard microbiological techniques. The results were compared to a database including all neonates with a positive MRSA cuture delivered to these mothers. RESULTS: 5732 pregnancies had screening culture results and infant infection data available. 22.9% of the mothers were positive for GBS, 14.5% for S. aureus of which 24.3% were MRSA (overall 4% maternal colonization with MRSA). Two infants whose mothers were MRSA-positive had positive MRSA cultures from a sterile site. One had a positive blood culture at two months of age. Following a vaginal delivery at 36 weeks’, this infant was transferred to another hospital for a truncus arteriosus repair then transferred back to the delivery hospital. The other had a positive CSF culture with a negative corresponding blood culture. This neonate was cultured during an initial episode of transient tachypnea following a vaginal delivery at 40 weeks’. The tachypnea rapidly resolved. The neonate was transferred to the well-baby nursery and remained asymptomatic. The managing clinicians felt that the positive CSF culture represented surface contamination and not MRSA meningitis. The MRSA isolates from this mother-infant pair were identical when compared by pulsed field gel electrophoresis and were also identical to another MRSA clone isolated from other patients in our hospital. These isolates did not match the predominant local MRSA clone associated with communityacquired MRSA infections. CONCLUSION: Recto-vaginal MRSA colonization is not uncommon among pregnant women, but does not appear to be associated with a high risk of vertically transmitted invasive early-onset infection in the neonate. S40 SMFM Abstracts
Self-generated analogies as a tool for constructing and evaluating explanations of scientific phenomena

How can students be taught to develop explanations for scientific phenomena on their own when their background knowledge is incomplete or poorly organized? Evidence from historical accounts of scientific discovery suggest that self-generated analogies—analogies produced by the learners themselves—are a tool by which individuals can generate, evaluate, and modify their own explanations. The central research questions for this study were: Can students use a series of self-generated analogies to bring about change in their understanding of a given scientific phenomenon, and what is the nature of the change in understanding? Participants were asked to create, apply, and modify their own analogies—as opposed to applying a specific analogy provided by an outsider—as a heuristic for constructing, evaluating, and modifying their own explanations for a given scientific phenomena. Nontrivial changes in explanation facilitated by the use of generative analogies were observed. Changes in understanding ranged from the emergence of new explanations to the raising of important questions about the nature of the phenomenon.
The role of macromolecular antifreeze in the darkling beetle, Meracantha contracta

Macromolecular antifreeze solutes are present in the hemolymph of the overwintering larvae of the darkling beetle,Meracantha contracta. These antifreeze solutes produce a thermal hysteresis in the hemolymph of overwinteringMeracantha larvae whereby the freezing point of the hemolymph may be 3–4 °C below the melting point. This thermal hysteresis is very similar to that produced by proteinaceous and glycoproteinaceous antifreezes which are used by many cold water, marine teleost fishes to prevent freezing. One function of the macromolecular antifreeze inMeracantha may be to hinder inoculative freezing which might otherwise occur because of the dampness of the hibernaculae. A probably more important function is to depress the supercooling point of the frost susceptibleMeracantha larvae, thereby preventing lethal ice formation in the larvae's body fluids down to temperatures of approximately −11 °C.
Ultrastructure of the rat testis after vasectomy.

To determine if the fine structure of the testis is altered as a result of vasectomy and if sperm produced after vasectomy are retained or disposed of the testes of 21 rats were examined by electron microscopy at intervals of 2 4 8 16 24 and 36 weeks after bilateral unilateral or bilateral sham vasectomy. Special attention was directed toward the ultrastructure of developing spermatids the cytology of Sertoli cells and the structural relationships between Sertoli cells and germ cells. No significant alterations were detected in these features as compared with normal rat testes and it is concluded that the fine structure of the rat testis remains normal after vasectomy. However further research is recommended since not every stage in spermatogenesis with its characteristic morphology could be examined. It is also possible that the vasectomy may cause changes in the testes after 9 postoperative months or that other species may react differently. The fate of postvasectomy-produced sperm could not be exactly determined but there was no evidence of increased phagocytosis by Sertoli cells suggesting that the seminiferous tubules are not the main site of sperm disposal in the rat.
Feature analysis of segmental errors in children with phonological disorders.

There has been a longstanding controversy about the existence, nature, and differentiation of developmental apraxia of speech (DAS), leading to numerous investigations of characteristics that defin...
Glutathione Peroxidase-1 Deficiency Augments Proinflammatory Cytokine-induced Redox Signaling and Human Endothelial Cell Activation

Glutathione peroxidase-1 (GPx-1) is a crucial antioxidant enzyme, the deficiency of which promotes atherogenesis. Accordingly, we examined the mechanisms by which GPx-1 deficiency enhances endothelial cell activation and inflammation. In human microvascular endothelial cells, we found that GPx-1 deficiency augments intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) expression by redox-dependent mechanisms that involve NFκB. Suppression of GPx-1 enhanced TNF-α-induced ROS production and ICAM-1 expression, whereas overexpression of GPx-1 attenuated these TNF-α-mediated responses. GPx-1 deficiency prolonged TNF-α-induced IκBα degradation and activation of ERK1/2 and JNK. JNK or NFκB inhibition attenuated TNF-α induction of ICAM-1 and VCAM-1 expression in GPx-1-deficient and control cells, whereas ERK1/2 inhibition attenuated only VCAM-1 expression. To analyze further signaling pathways involved in GPx-1-mediated protection from TNF-α-induced ROS, we performed microarray analysis of human microvascular endothelial cells treated with TNF-α in the presence and absence of GPx-1. Among the genes whose expression changed significantly, dual specificity phosphatase 4 (DUSP4), encoding an antagonist of MAPK signaling, was down-regulated by GPx-1 suppression. Targeted DUSP4 knockdown enhanced TNF-α-mediated ERK1/2 pathway activation and resulted in increased adhesion molecule expression, indicating that GPx-1 deficiency may augment TNF-α-mediated events, in part, by regulating DUSP4.
Suppression of Noise in a Noisy Optical Trap

We have experimentally explored and clarified the concept of noise suppression in intrinsically noisy systems by adding noise at the input using a microscopic bead held in a moving and intensity-modulated optical trap. By coupling the stiffness of the optical trap to its position, we have explicitly constructed an experimental model system in which added fluctuations in the trap position result in reduced variance of the observed bead position as compared to a stationary trap. This reduction in variance and the spectral properties of the observed output noise agree with theoretical predictions. Our experiment demonstrates that the essential aspect of noise reduction in such a system is that the added fluctuations drive the system into states with a reduced intensity of intrinsic noise sufficiently often.
Pressure–morphology relationship of a released carpal tunnel

We investigated morphological changes of a released carpal tunnel in response to variations of carpal tunnel pressure. Pressure within the carpal tunnel is known to be elevated in patients with carpal tunnel syndrome and dependent on wrist posture. Previously, increased carpal tunnel pressure was shown to affect the morphology of the carpal tunnel with an intact transverse carpal ligament (TCL). However, the pressure-morphology relationship of the carpal tunnel after release of the TCL has not been investigated. Carpal tunnel release (CTR) was performed endoscopically on cadaveric hands and the carpal tunnel pressure was dynamically increased from 10 to 120 mmHg. Simultaneously, carpal tunnel cross-sectional images were captured by an ultrasound system, and pressure measurements were recorded by a pressure transducer. Carpal tunnel pressure significantly affected carpal arch area (p 62 mm(2) at 120 mmHg. Carpal arch height, length, and width also significantly changed with carpal tunnel pressure (p < 0.05). As carpal tunnel pressure increased, carpal arch height and length increased, but the carpal arch width decreased. Analyses of the pressure-morphology relationship for a released carpal tunnel revealed a nine times greater compliance than that previously reported for a carpal tunnel with an intact TCL. This change of structural properties as a result of transecting the TCL helps explain the reduction of carpal tunnel pressure and relief of symptoms for patients after CTR surgery.
Enhancing Baccalaureate Student Learning in Research and Gerontology Through Partnership With an Area Agency on Aging

Designing an effective research learning experience for undergraduate social work students is challenging. Similarly, although content on elderly adults is a natural fit in many parts of the undergraduate curriculum, doing so in a research course can be a difficult challenge. Described in this article is an undergraduate research course that has achieved both of these goals and also made significant contributions to an aging agency and, ultimately, its clients. The authors discuss relevant literature, influential factors in the course's development, outcome data, and elements identified as key to the course's success.
Crystallography and magnetism of 2-amido-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazole-3-oxide-1-oxyls

Abstract Two 2-Ar-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazole-3-oxide-1-oxyl radicals were synthesized (Ar = para-acetamidophenyl, and para-(tert-butyloxycarbonyl)aminophenyl, pAPNN, pBPNN) that incorporate amide-type NH moieties as potential hydrogen bonding sites. Both form hydrogen bonded cyclic dyads, but pAPNN exhibits spin pairing (2J/k = (−)5 K) due to a close, antiparallel nitroxide-nitroxide stacking contact, while pBPNN is essentially paramagnetic.
Images as institution builders: Metropolitan planning in Madrid

Abstract This article chronicles recent changes in planning practice. It documents the rise of strategic planning and the move toward proactive planning centered on strategy, marketing, publicity and images. The author studies two cases. One is sub‐regional, of the ‘Great South’ of metropolitan Madrid. The other is regional, of the program ‘Madrid Metropolitan Region’. Planners created physical designs and rhetoric that encapsulated new images for the south and the entire metro area. The planners used the evoking image to craft the strategy, implement it, and build the institutions of regional planning and government. These cases suggest that external images (plans, photos) and internal images (in the mind's eye) are key to understanding how planning processes worked. It reveals the role images played in planning and political discourse, and how discourse was based on the image.
2002 IEEE PES Summer Meeting Call for Papers

Feeding electric loads independent of power utilities is an important task that is done by using a stand-alone synchronous generator (alternator). Automatic regulation of the output voltage of these alternators is necessary, especially if the load demand changes over a wide range. Many schemes are offered in the literature for such an automatic voltage regulator (AVR). This letter introduces an AVR based on recently developed artificial intelligence tools for modeling and control.
Itraconazole alters the pharmacokinetics of atorvastatin to a greater extent than either cerivastatin or pravastatin.

Background 3-Hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) are metabolized by distinct pathways that may alter the extent of drug-drug interactions. Cerivastatin is metabolized by cytochrome P450 (CYP)3A4 and CYP2C8. Atorvastatin is metabolized solely by CYP3A4, and pravastatin metabolism is not well defined. Coadministration of higher doses of these statins with CYP3A4 inhibitors has the potential for eliciting adverse drug-drug interactions. Objective To determine the comparative effect of itraconazole, a potent CYP3A4 inhibitor, on the pharmacokinetics of cerivastatin, atorvastatin, and pravastatin. Methods In this single-site, randomized, three-way crossover, open-labeled study, healthy subjects (n = 18) received single doses of cerivastatin 0.8 mg, atorvastatin 20 mg, or pravastatin 40 mg without and with itraconazole 200 mg. Pharmacokinetic parameters [AUC(0-∞), AUC(0-tn), peak concentration (Cmax), time to reach Cmax (tmax), and half-life (t½)] were determined for parent statins and major metabolites. Results Concomitant cerivastatin/itraconazole treatment produced small elevations in the cerivastatin AUC(0-∞), Cmax, and t½ (27%, 25%, and 19%, respectively; P < .05 versus cerivastatin alone). Itraconazole coadministration produced similar changes in pravastatin pharmacokinetics [AUC elevated 51% (P < .05 versus pravastatin alone), 24% (Cmax), and 23% (t½), respectively]. However, itraconazole dramatically increased atorvastatin AUC (150%), Cmax (38%), and t½ (30%) (P < .05). The elevation in atorvastatin AUC was significantly greater than that of cerivastatin (P < .005) or pravastatin (P < .005). Conclusion Itraconazole markedly elevated atorvastatin plasma levels (2.5-fold) after 20 mg dosing, suggesting that concomitant itraconazole/atorvastatin therapy be carefully considered. Itraconazole produced modest elevations in the plasma levels of cerivastatin 0.8 mg or pravastatin 40 mg (1.3-fold and 1.5-fold, respectively), indicating that combination treatment with itraconazole with cerivastatin or pravastatin may be preferable. (Clin Pharmacol Ther 2000;68:391-400.) Clinical Pharmacology & Therapeutics (2000) 68, 391–400; doi: 10.1067/mcp.2000.110537
INCLUSIVE REACTIONS AND DUAL-RESONANCE MODELS.

The theoretical and phenomenological advantages of looking at inclusive-type reactions in dual-resonance models are discussed. The case of single-particle distributions is considered in some detail, and part of the contributions explicitly evaluated. We find that such contributions exhibit "scaling" behavior of the type observed long ago by Amati, Fubini, and Stanghellini in the multiperipheral model and which was reproposed in more precise terms recently by Feynman and by Benecke, Chou, Yang, and Yen. The explicit form of the limiting distribution is given. A similar behavior is found in the case of the multiparticle distribution. The need of manageable techniques for computing high-energy limits of dual loop discontinuities is stressed. We finally comment on the possible relevance of our results on deriving bootstrap-type conditions from duality and in providing a way to understand the connection between the dual-resonance model and other models of current interest.
Effects of Water Vapor on the Initial Sintering of Calcia

The effect of water vapor on the initial sintering kinetics of calcium oxide was studied at 920” to 1123°C. In the range of PHI() from 8 × 10W4 to 487 mm Hg, water vapor increased the rate of sintering. The initial sintering kinetics followed the model for volume diffusion with calculated diffusion coefficients dependent on PH2O, which varied from (P,H2O)1/2 at pressures between 6.1 and 50 mm Hg to (PIH2O)1/2 at pressures between 244 and 487 mm Hg. The activation enthalpy varied from 123 ± 7 kcal/mole when PH2O= 0.04 mm Hg to 103 ± 3.5 kcal/mole at PH2O 243.9 mm Hg.
Reflective journaling: developing an online journal for distance education

Reflective journal writing can be a useful heuristic tool to foster critical thinking skills and develop reflective clinical practice in nursing. When combined with a distance education delivery format, the online journal helps to leverage the strengths of reflective learning with educational technology as well as provide a seamless record of learning outcomes across the curriculum. The authors discuss the incorporation of an online reflective journal into a distance education clinical course and provide guidelines for educators considering a similar approach.
Direct Fibrogenic Effects of Dispersed Single-Walled Carbon Nanotubes on Human Lung Fibroblasts

Nanomaterials, including single-walled carbon nanotubes (SWCNT), are being developed for a variety of commercial products. However, adverse health effects attributed to these new materials are not well understood. Recent reports showed that exposure of mice to dispersed SWCNT (DSWCNT) produced a rapid and progressive interstitial lung fibrosis without persistent inflammation. To understand the mechanism underlying this unusual fibrogenicity of DSWCNT, the present investigation focused on the direct bioactivity of DSWCNT using a cell culture of lung fibroblasts that represent a major cell type resident in the lung interstitium and responsible for the production of collagen matrix. At concentrations relevant to those used in vivo, in vitro exposure of lung fibroblasts to DSWCNT stimulated cell proliferation and induced collagen production without producing cell damage. One of the major matrix metalloproteinases (MMP), MMP-9, which is known to be involved in lung fibrosis, was also elevated by DSWCNT treatme...
Long-term rectal function after permanent prostate brachytherapy.

Purpose: To evaluate the effect of prostate brachytherapy with or without supplemental therapies on long-term rectal function by means of a patient-administered quality-of-life instrument. Materials and Methods: As part of an ongoing prospective evaluation, 164 of an initial 209 patients who remain alive were mailed the Rectal Function Assessment Score (R-FAS) with a prestamped return envelope. R-FAS range from 0 to 27 with lower scores being indicative of better bowel function. Of the 162 eligible patients, 161 (99.4%) returned the survey. Median follow-up was 9.0 years (range 8.2–11.2 years). Clinical, treatment, and dosimetric parameters evaluated for bowel function included patient age, diabetes, hypertension, tobacco consumption, clinical T stage, elapsed time since brachytherapy, ultrasound volume, planning target volume, androgen deprivation therapy, supplemental external beam radiation, isotope, rectal dose, prostate D100/D150/D200, and prostate D90. Results: For the entire cohort, the current R-FAS was 3.59, which represented a nonstatistical improvement from prior surveys in 1999 (4.29) and 2002 (3.92) (P 0.134). Only 16 patients (9.9%) reported bowel function to be worse after brachytherapy. Of the clinical, treatment, and dosimetric parameters evaluated, only the number of preimplant bowel movements, tobacco use, and diabetes correlated with R-FAS. Despite lower rectal doses with 103 Pd, isotope did not predict for bowel function. Consistent with prior surveys, patient perception of overall rectal quality of life was inversely related to supplemental external beam radiation (P 0.027). Conclusion: Prostate brachytherapy adversely affects bowel function. However, in most patients the changes are minimal and slowly resolve with time. Overall rectal quality of life is inversely related to supplemental external beam radiation.
A note on matricial minimality

Abstract Let A be a complex n×n matrix, θ a matricial norm and r(A) the spectral radius of A. Then, it is known [2,7], r(A⩽r(θ(A)). In our present note we investigate when r(A−αIn)=r(θ(A−αIn))∀αϵC.
Amplitude rise time and the perception of the voiceless affricate/fricative distinction.

Variation of amplitude envelope at stimulus onset has been considered to be of primary importance for distinguishing voiceless affricates from fricatives (e.g., |t∫| and |∫|). In earlier perceptual experiments, however, variation in amplitude rise time was confounded with variation in frication duration. In two experiments, these variables were independently manipulated, and their individual and combined effects for perception of |t∫| and |∫| were examined. Variation in amplitude rise time alone was not sufficient to signal the voiceless affricate/fricative contrast in these experiments, but variation in frication duration alone was sufficient.
Dispelling negative expectancies: The impact of interaction goals and target characteristics on the expectancy confirmation process.

Abstract The present study examined the impact of the interaction goals of perceivers and the characteristics of targets of a negative expectancy on the expectancy confirmation process. Perceivers were led to expect that their future interaction partner might have difficulty performing well under pressure. Perceivers were also placed in an interaction setting that made one of two interaction goals relevant: whereas some were encouraged to consider the partner as a possible teammate for a cooperative game; others were encouraged to have a casual conversation. Orthogonal to the interaction manipulation, subjects interacted with a target whose expectancy-relevant characteristics, if discovered during the interaction, could either support or refute the expectancy. Results indicated that the interaction goals perceivers inferred from the interaction setting influenced the extent to which they probed for information relevant to their negative expectancies. Their search strategies influenced what they discovered about the target, and these strategy-dependent discoveries, in turn, shaped their final impressions of the target. From this we argue that both the interaction goals of the perceivers and the characteristics of the targets of a negative expectancy are critical determinants of the fate of negative expectancies.
Assessing Perceived Physical Environmental Variables that May Influence Physical Activity

The present study evaluated a measure of perceived physical environments that may influence physical activity. Forty-three self-report items were used to assess environmental variables at homes, in neighborhoods, or on frequently traveled routes. The presence of facilitators of (e.g., equipment, programs, attractive surroundings) and barriers to (e.g., high crime) physical activity was assessed. In 110 college students, test-retest reliabilities were .89 for the home equipment scale, .68 for the neighborhood scale, and .80 for the convenient facilities scale. Home equipment and convenient facilities scales were correlated with self-reported physical activity. In multiple regression analyses, the only significant association, after adjusting for neighborhood socioeconomic status, was home equipment with strength exercise. Further research is needed to identify other environmental characteristics that may influence physical activity.
Cultural Diversity in Geography Curriculum: The Geography of American Indians

Abstract This paper discusses the role of geography curriculum in teaching cultural diversity by examining the course content in one course taught at the University of Minnesota-Duluth. The course, The Geography of American Indians in the United States and Canada, included lectures, student projects, outside activities, and an evaluation of learning. Course content is identified and three lectures based on Great Lakes Chippewa geography are summarized. Evaluation of learning indicates students improved geographical skills, increased their knowledge of spatial and ecological characteristics of American Indian culture groups, and became familiar with historical and legal parameters of resources use conflicts between local Great Lakes Chippewa and non-Indians in northern Wisconsin.
Interference with polyhedral inclusion body (PIB) production inTrichoplusia ni cells infected with a high passage strain ofAutographa californica nuclear polyhedrosis virus (NPV)

Trichoplusia ni cells infected with a low passage (LP) strain ofAutographa californica nuclear polyhedrosis virus (NPV) produce large numbers of polyhedral inclusion bodies (PIBs). Interference with PIB production occurs whenT. ni cells are first inoculated with a high passage (HP) strain and then challenged with the LP strain. PIB production is reduced 100 fold to the level seen with HP virus infection only.
Genetic population structure of Tectura paleacea: implications for the mechanisms regulating population structure in patchy coastal habitats.

The seagrass limpet Tectura paleacea (Gastropoda; Patellogastropoda) belongs to a seagrass obligate lineage that has shifted from the Caribbean in the late Miocene, across the Isthmus of Panama prior to the closing of the Panamanian seaway, and then northward to its modern Baja California – Oregon distribution. To address whether larval entrainment by seagrass beds contributes to population structuring, populations were sampled at six California/Oregon localities approximately 2 degrees latitude apart during two post-settlement periods in July 2002 and June 2003. Partial cytochrome oxidase b (Cytb) sequences were obtained from 20 individuals (10 per year) from each population in order to determine the levels of population subdivision/connectivity. From the 120 individuals sequenced, there were eighty-one unique haplotypes, with the greatest haplotype diversity occurring in southern populations. The only significant genetic break detected was consistent with a peri-Point Conception (PPC) biogeographic boundary while populations north and south of Point Conception were each panmictic. The data further indicate that populations found south of the PPC biogeographic boundary originated from northern populations. This pattern of population structure suggests that seagrass patches are not entraining the larvae of T. paleacea by altering flow regimes within their environment; a process hypothesized to produce extensive genetic subdivision on fine geographic scales. In contrast to the haplotype data, morphological patterns vary significantly over very fine geographic scales that are inconsistent with the observed patterns of genetic population structure, indicating that morphological variation in T. paleacea might be attributed to differential ecophenotypic expression in response to local habitat variability throughout its distribution. These results suggest that highly localized conservation efforts may not be as effective as large-scale conservation efforts in near shore marine environments.
Interactions between a helical residue and tertiary structures: helix propensities in small peptides and in native proteins.

Abstract We compare three complete sets of helix propensities for the 20 naturally occurring amino acids. These propensities are derived from three different experimental systems: small synthetic peptides, coiled-coil dimers, and real proteins. Thermodynamic analyses show that propensities from the different sets should be perfectly correlated if (1) the helix in a protein is formed when and only when the protein is folded (tight-coupling); and (2) the amino acid side-chains are not involved in tertiary interactions. A simple thermodynamic model is proposed in order to understand those systems that fail (1). The model incorporates fluctuations in both native and unfolded states of the protein. Measurements on hydrogen-exchange rate from proteins also question the validity of (2). A complementary model that assumes a cooperation between helix formation and tertiary structures through side-chain interactions can explain the correlation between data from the peptides and proteins. One possible source of this side-chain tertiary interaction is the amphiphilicity of helices in proteins. Our model is consistent with the ideas of “minimal frustration” and “protein malleability”; it exhibits entropy–enthalpy compensation, and suggests that local unfolding and solvent penetration are correlated in a fluctuating protein. It also suggests experiments to quantitatively verify and differentiate between the models. The electrostatic nature of hydrogen bonding and its manifestations in protein helix stability is also discussed.
An assessment of biological interactions in an epilithic stream community using time-lapse cinematography

In situ time-lapse cinematography was used to record and enumerate behavioral interactions between members of an epilithic insect community in a small Michigan (U.S.A.)trout stream. 145 interactions were observed during 78 hours of filming. Most of these (98%) involved simuliid larvae. Interactions between simuliid larvae occurred at about the same frequency as interactions between simuliids and other taxa. However, interactions between simuliid larvae were less likely to lead to emigration than were interactions between blackflies and other groups. Significant short-term fluctuations of faunal density on filmed surfaces were also observed. The causes of these fluctuations appeared varied. The results of a preliminary assessment of interactions and the usefulness of this technique are discussed.
Neurotoxicology: Five new things

Summary Neurotoxic disease can mimic many common neurologic disease states, including parkinsonism, myelopathy, neuropathy, and encephalopathy. Accurate diagnosis and appropriate treatment may result in a favorable outcome. This review highlights 5 areas of neurotoxicology for which there is an emerging understanding of disease processes or patterns of exposure, including 3 specific metal toxicities (manganism, zinc-induced copper deficiency, and cobalt-chromium neuropathy). Toxin-induced posterior reversible encephalopathy syndrome is more widely recognized and reported in association with an ever-growing list of drugs. Two new categories of street drugs, synthetic cathinones and cannabinoids, have been identified as public health threats due to their popularity, availability, and severity of toxicity.
FINITE ELEMENT MODELING OF PRESTRESSED CONCRETE CROSSTIES WITH BALLAST AND SUBGRADE SUPPORT

With the first major installation in North American railroads during the 1960’s, concrete ties were believed to last longer than timber ties and have the potential for reduced life cycle costs. However, their characteristic response to initial pretension release as well as dynamic track loading is not well understood. In North America, concrete ties have been found vulnerable to rail seat deterioration (RSD), but the mechanisms contributing to RSD failures are not well understood. To improve such understanding, a comprehensive computational study of the tie response to dynamic track forces is needed. This paper presents an initial research effort in this direction that models concrete crossties as heterogeneous media in three-dimensional finite element analyses, i.e., the prestressing strands, concrete matrix and the strand-concrete interfaces are represented explicitly. Damaged plasticity models are employed for the concrete material, and linear elastic bond-slip relations, followed by damage initiation and evolution, are adopted for the strand-concrete interfaces. Further, the ballast is modeled with an Extended Drucker-Prager plasticity model, and the subgrade is modeled as an elastic half space. All material parameters are obtained from the open literature. Currently the rail fastening systems are not included in modeling. Two loading scenarios are simulated: pretension release and direct rail seat loading. The modeling approach is able to predict the deformed tie shape, initial interface deterioration, the compressive stress state in concrete and residual tension in the strands upon pretension release. The transfer lengths of the prestressing strands can be readily calculated from the analysis results. Further predicted are the rail seat force-displacement characteristics and the potential failure mode of a concrete crosstie under direct rail seat loading. The responses of two railroad concrete crossties with 8-strand and 24-wire reinforcements, respectively, are studied using the presented modeling framework. The analyses indicate a potential failure mode of tensile cracking at the tie base below the rail seats. The results show that the 24-wire tie is better able to retain the pretension in the reinforcements than the 8-strand tie, resulting in slightly stronger rail seat force-displacement characteristics and higher failure load. The effects of the load application method and the subgrade modeling on the predicted tie response are further studied.
Plasma 8-iso-prostaglandin F2α, a marker of oxidative stress, is increased in patients with acute myocardial infarction

Background: Oxidative stress has been implicated in the pathogenesis of atherogenesis. The aim of our study is to examine whether the plasma 8-iso-prostaglandin F2α level, a marker of oxidative stress, is elevated in patients with acute myocardial infarction.Methods: Three groups of patients were enrolled: (1) patients with no or minimal coronary artery disease (CAD) (n = 15); (2) patients with stable CAD (n = 31); (3) patients with acute myocardial infarction (n = 13).Results: Plasma 8-iso-prostaglandin F2α levels were significantly elevated (p < 0.001) in patients with acute myocardial infarction (290.7 ± 73.9 pg/ml) as compared to patients with stable CAD (182.0+75.7 pg/ml) and patients with no significant CAD (118.9 ± 85.5 pg/ml). This remained significant after correcting for coronary atherosclerosis risk factors, age, extent of atherosclerosis, and C-reactive protein (CRP) level.Conclusion: Plasma 8-iso-prostaglandin F2α levels are elevated in patients with acute myocardial infarction. Endogenous ox...
An approach to identification of linear systems and the optimal solution of a class of synthesis problems

A new formulation of the problem of identification of the impulse response of a discrete time linear time invariant system from a finite set of finite length noisy I-O measurements is given. This transforms the problem to an input estimation problem of a new type. We present a solution to this input estimation problem in the framework of maximum a posteriori (MAP) estimation. This involves an optimization problem of a special type which we solve largely based on some recent results in linear system theory related to system structure and the geometric and polynomial theories of linear systems which are algebraic in nature. Furthermore, the solution to the identification problem we consider in this paper also provides a solution to the problems of 1) Deadbeat output control with internal stability by minimum norm input, 2) Disturbance decoupling with internal stability by minimum norm input, and 3) Exact model matching of linear systems by minimum norm compensators.