cssi/SciSciGPT-SciSciNet huggingface dataset:
RNAi in Human Cells: Basic Structural and Functional Features of Small Interfering RNA

We investigated the mechanism of RNA interference (RNAi) in human cells. Here we demonstrate that the status of the 5' hydroxyl terminus of the antisense strand of a siRNA determines RNAi activity, while a 3' terminus block is tolerated in vivo. 5' hydroxyl termini of antisense strands isolated from human cells were phosphorylated, and 3' end biotin groups were not efficiently removed. We found no requirement for a perfect A-form helix in siRNA for interference effects, but an A-form structure was required for antisense-target RNA duplexes. Strikingly, crosslinking of the siRNA duplex by psoralen did not completely block RNA interference, indicating that complete unwinding of the siRNA helix is not necessary for RNAi activity in vivo. These results suggest that RNA amplification by RNA-dependent RNA polymerase is not essential for RNAi in human cells.
The Relation Between the New Corporate Governance Rules and the Likelihood of Financial Statement Fraud

This study examines the relation between the likelihood of financial statement fraud and certain corporate governance requirements of the Sarbanes‐Oxley Act and the new rules of the NYSE and the NASDAQ stock markets. Results based upon a logit regression analysis on a sample of 111 fraud firms and 111 matched no‐fraud firms indicate that fraud likelihood is lower when audit committee is comprised solely of independent directors and when audit committee members have smaller number of directorships with other companies. Board of director independence, audit committee expertise and nominating committee independence are not significant variables in reducing fraud likelihood. The study also investigates several other corporate governance variables and finds that fraud likelihood is lower when audit committee has longer tenure and chief executive officer is not chairman of the board. These results highlight two new significant aspects of audit committee: the directorships of its members with other firms and the committee members' tenure. The results have direct implications for further improvement of corporate governance.
Developmental aluminum toxicity in mice can be modulated by low concentrations of minerals (Fe, Zn, P, Ca, Mg) in the diet.

Female Swiss Webster mice were fed diets containing 7 (control) or 1000 µg Al/g diet from conception to weaning. Pregnancy weight gain, brith weight, litter size, postnatal mortality, and weaning weight were measured. In different groups, diets low in Fe, Zn, P, or Ca and Mg (CaMg) were used as basal diets, to which Al was added. Relative to controls, who received NRC recommended levels of these nutrients, all diets with marginal essential trace elements impacted development, as demonstrated by effects on birth weight (CaMg, Fe) or weaning weight (Fe, Zn, P). Compared to diets low in Al, the 1000-mg Al/g diet led to reduced weaning weight regardless of the essential element content of the diet. Other end points were influenced by Al only within the basaldiet group; pregnancy weight gain with the low-P diet, litter size with the low-Fe diet, pregnancy completion with the low-Zn diet, and postnatal mortality with the low-CaMg or low-Zn diet. Thus, diets marginal in selected minerals can differentially alter the toxicological profile of developmental Al exposures. A basal diet was also used in which the NRC diet was supplemented with ascorbic acid, which promotes Al absorption. No modification of Al toxicity was seen with ascorbic acid supplementation.
Reconciling NOx emissions reductions and ozone trends in the U.S., 2002–2006

Abstract Dynamic evaluation seeks to assess the ability of photochemical models to replicate changes in air quality as emissions and other conditions change. When a model fails to replicate an observed change, a key challenge is to discern whether the discrepancy is caused by errors in meteorological simulations, errors in emission magnitudes and changes, or inaccurate responses of simulated pollutant concentrations to emission changes. In this study, the Community Multiscale Air Quality (CMAQ) model is applied to simulate the ozone (O3) change after the NOx SIP Call and mobile emission controls substantially reduced nitrogen oxides (NOx) emissions in the eastern U.S. from 2002 to 2006. For both modeled and observed O3, changes in episode average daily maximal 8-h O3 were highly correlated (R2 = 0.89) with changes in the 95th percentile, although the magnitudes of reductions increased nonlinearly at high percentile O3 concentrations. Observed downward changes in mean NOx (−11.6 to −2.5 ppb) and 8-h O3 (−10.4 to −4.7 ppb) concentrations in metropolitan areas in the NOx SIP Call region were under-predicted by 31%–64% and 26%–66%, respectively. The under-predicted O3 improvements in the NOx SIP Call region could not be explained by adjusting for temperature biases in the meteorological input, or by considering uncertainties in the chemical reaction rate constants. However, the under-prediction in O3 improvements could be alleviated by 5%–31% by constraining NOx emissions in each year based on observed NOx concentrations. This demonstrates the crucial need to accurately characterize changes in precursor emissions when dynamically evaluating a model's ability to simulate O3 responses to those changes.
Localization of the heparin binding exosite of factor IXa.

Factor IXa (FIXa) is known to have a binding site for heparin that has not been mapped by a mutagenesis study. By homology modeling based on structural data, we identified eight basic residues in the catalytic domain of FIXa that can potentially bind to heparin. These residues, Lys98, Lys126, Arg165, Arg170, Lys173, Lys230, Arg233, and Lys239(chymotrypsin numbering) were substituted with Ala in separate constructs in Gla-domainless forms. Following activation, it was found that all FIXa derivatives cleaved the chromogenic substrate CBS 31.39 with near normal catalytic efficiencies. Similarly, antithrombin inactivated FIXa derivatives with a similar second-order association rate constant (k 2) in both the absence and presence of pentasaccharide. In the presence of a full-length heparin, however, k 2 values were dramatically impaired with certain mutants. Direct binding studies revealed that the same mutants lost their affinities for binding to heparin-Sepharose. Both kinetic and direct binding data indicated that five basic residues of FIXa in the following order of importance, Arg233 > Arg165 > Lys230 > Lys126 > Arg170 are critical for binding to heparin. Consistent with these results, examination of the crystal structure of the catalytic domain of FIXa indicated that all five basic residues are spatially aligned in a manner optimal for interaction with heparin.
Gegenbauer expansions for three-electron integrals

An arbitrary power of ‖r i - r j ‖ can be expanded in terms of the magnitudes of r i and r j and Gegenbauer polynomials whose argument is the cosine of the angle between these two vectors. The Gegenbauer expansion has seenlittle use in the evaluation of three-electron integrals because the Gegenbauer polynomials are not orthogonal when integrated over the angular variables of a spherical coordinate system. It is shown here that this disadvantage is easily overcome and that the resulting formulas are not only simple and compact but also particularly suitable for the application of truncation and/or convergence acceleration schemes.
Kármán vortex formation from a cylinder: Role of phase‐locked Kelvin–Helmholtz vortices

The formation length of Karman vortices can be drastically reduced by small‐amplitude excitation at a frequency much higher than the natural frequency of Karman vortex formation, namely the Kelvin–Helmholtz (KH) frequency of the separating shear layer. Phase‐locked patterns of KH vortices are attainable. These spatially stationary patterns coexist, however, with the spatial and temporal development of the Karman vortices.
Hydrothermal Synthesis of Structure‐ and Shape‐Controlled Manganese Oxide Octahedral Molecular Sieve Nanomaterials

Highly uniform single-crystal Na-OMS-2 (OMS: octahedral molecular sieve), pyrolusite, and γ-MnO2 nanostructures with an interesting 3D urchinlike morphology have been successfully prepared using a hydrothermal method based on a mild and direct reaction between sodium dichromate and manganese sulfate. The crystal phases, shapes, and tunnel sizes of the manganese dioxide nanostructures can be tailored. Reaction temperature, concentrations of the reactants, and acidity of the solution play important roles in controlling the synthesis of these manganese dioxides. Field-emission scanning electron microscopy and transmission electron microscopy (TEM) studies show that the nanomaterials obtained are constructed of self-assembled nanorods. X-ray diffraction and TEM results indicate that the constituent manganese dioxide particles are single-crystalline materials. Energy dispersive X-ray analysis and magnetic studies imply that chromium cations may be incorporated into the framework and/or tunnels of the manganese dioxides. A mechanism for the growth of manganese dioxides with urchinlike architectures is proposed.
Transmission of concentrated forces into prismatic shells—II

Abstract The paper treats the remaining two cases of an unbounded prismatic shell subjected to concentrated forces at the ridge. When the load is perpendicular to the plane of symmetry of the shell, the membrane forces remain bounded, while the moments and transverse shearing forces are singular at the load point. In contrast, the membrane forces dominate the far field. When the concentrated force is applied in the direction of the ridge, the membrane and transverse shearing forces are singular and both are of the same order at the point of loading. The far field for this case again is dominated by the membrane forces.
Force generation in the outer hair cell of the cochlea

The outer hair cell of the mammalian cochlea has a unique motility directly dependent on the membrane potential. Examination of the force generated by the cell is an important step in clarifying the detailed mechanism as well as the biological importance of this motility. We performed a series of experiments to measure force in which an elastic probe was attached to the cell near the cuticular plate and the cell was driven with voltage pulses delivered from a patch pipette under whole-cell voltage clamp. The axial stiffness was also determined with the same cell by stretching it with the patch pipette. The isometric force generated by the cell is around 0.1 nN/mV, somewhat smaller than 0.15 nN/mV, predicted by an area motor model based on mechanical isotropy, but larger than in earlier reports in which the membrane potential was not controlled. The axial stiffness obtained, however, was, on average, 510 nN per unit strain, about half of the value expected from the mechanical isotropy of the membrane. We extended the area motor theory incorporating mechanical orthotropy to accommodate the axial stiffness determined. The force expected from the orthotropic model was within experimental uncertainties.
On the localization of sarcotubular ATPase activity in mammalian skeletal muscle

ATPase activity of the sarcoplasmic reticulum has been demonstrated at the level of the light microscope. Although this membrane system is usually viewed as ultrastructural in its dimensions, it was possible to identify sarcotubular enzymic activity in frozen sections. In skeletal muscle fibers of the rat diaphragm, sarcotubular ATPase can be distinguishedin situ from ATPases associated with mitochondria and myofibrils. This is possible because chemical properties are more readily analyzed in frozen sections than in material prepared for electron microscopy. Pour different ATPases have thus been localized in skeletal muscle fibers by taking advantage of differences in the pH optima of these enzymes and in their response to various inhibitors and activators. The following cytochemical and morphological features have been demonstrated: These results suggest the possibility that the two sites of sarcotubular activity reflect two different roles of ATPase in this membrane system. Activity at the triads might be involved indirectly in making available the calcium necessary for muscular contraction, that is, by binding calcium which can be released at the time of contraction. Activity at the H bands might be more directly involved in the rebinding of calcium leading to relaxation of the muscle.
Long-term outcome and reintervention after endovascular abdominal aortic aneurysm repair using the Zenith stent graft

Objective To assess the long-term performance of the bifurcated Zenith stent graft. Methods A total of 325 patients (300 men and 25 women) underwent elective endovascular abdominal aortic aneurysm repair with bifurcated Zenith stent grafts between October 1998 and December 2005. Follow-up included routine contrast-enhanced computed tomography and multiview abdominal radiographs at 1, 6, and 12 months and yearly thereafter. Data on late-occurring (>30 days after stent-graft implantation) complications and interventions were collected prospectively. Results Of the original 325 patients, 92 have since died, resulting in a mean follow-up of 2.3 years (range, 1 month to 7.0 years). Nine (2.8%) of 325 patients required reintervention to treat or prevent endoleak (type I or III) or graft occlusion at an average of 1.4 years after stent-graft placement (range, 40 days to 4.0 years). Three (0.9%) of these patients died from causes related to malfunction of the stent graft: one each from aneurysm rupture, stent-graft infection, and infection of a femoral-femoral bypass graft placed after limb occlusion. Nineteen additional patients (5.8%) required treatment for type II endoleak, for a total reintervention rate of 8.6%. Conclusions Late failures of Zenith stent-graft attachment, structure, or function are rare. In the absence of known endoleak, routine follow-up imaging plays a limited role in the identification and prevention of impending failure.
The postnatal role of Sox9 in cartilage

Sox9 is an essential transcription factor for the differentiation of the chondrocytic lineage during embryonic development. To test whether Sox9 continues to play a critical role in cartilaginous tissues in the adult mice, we used an inducible, genetic strategy to disrupt the Sox9 gene postnatally in these tissues. The postnatal inactivation of Sox9 led to stunted growth characterized by decreased proliferation, increased cell death, and dedifferentiation of growth plate chondrocytes. Upon postnatal Sox9 inactivation in the articular cartilage, the sulfated proteoglycan and aggrecan content of the uncalcified cartilage were rapidly depleted and the degradation of aggrecan was accompanied by higher ADAMTS5 immunostaining and increased detection of the aggrecan neoepitope, NITEGE. In spite of the severe loss of Collagen 2a1 mRNA, the Collagen II protein persisted in the articular cartilage, and no histopathological signs of osteoarthritis were observed. The homeostasis of the intervertebral disk (IVD) was dramatically altered upon Sox9 depletion, resulting in disk compression and subsequent degeneration. Inactivation of Sox9 in the IVD markedly reduced the expression of several genes encoding extracellular matrix proteins, as well as some of the enzymes responsible for their posttranslational modification. Furthermore, the loss of Sox9 in the IVD decreased the expression of cytokines, cell-surface receptors, and ion channels, suggesting that Sox9 coordinates a large genetic program that is instrumental for the proper homeostasis of the cells contained in the IVD postnatally. Our results indicate that Sox9 has an essential role in the physiological control of cartilaginous tissues in adult mice. © 2012 American Society for Bone and Mineral Research.
Nonlinear effects in edge waves

Nonlinear corrections to Stokes's linear edge-wave solution are obtained by means of perturbation expansions in the amplitude. The shallow-water formulation is considered first, but even for small beach angles β the behaviour in the deep water offshore becomes important and this formulation is limited. In the full formulation, amplitude dependence is required in the dispersion relation and in the exponents for the exponential decay away from the shore. There is a non-uniformity in the results as β → ½ π, which is corrected by a special perturbation expansion.
Identification of an autocrine mechanism for regulating cell-cycle progression in murine keratinocytes

Primary murine keratinocytes possess a limited doubling potential regardless of plating density or the inclusion of competence factors insulin, epidermal growth factor, and/or fetal bovine serum within the culture medium. In contrast, a murine cell line (CH-72), derived from a 7,12-dimethylbenz[a]-anthraceneinitiated, 12-O-tetra-decanoylphorbol-13-acetate-promoted mouse skin carcinoma, was found to exhibit unlimited proliferative potential; this was demonstrated by the ability of these cells to produce the progression factor required for entry into the DNA-synthesis phase in the absence of competence-factor stimulation. Conditioned medium, collected from murine carcinoma cells, was subsequently shown to increase the level of [3H] thymidine incorporation in competence-factor-deprived CH-72 cultures by more than a factor of 4 within 16h. Moreover, consistent with its ability of recruit cells cycling within the first gap phase directly into the DNA-synthesis phase, the autocrine progression factor present in conditioned medium decreased the G1 ∶ S ratio from the 55 ∶ 29 observed with growth medium controls to 38 ∶ 46. Preliminary characterization of the autocrine factor produced by cultured murine carcinoma cells using gel-filtration chromatography revealed a molecular mass of less than 2 kDa, similar in size to the factor previously shown by our laboratory to promote G1-phase progression in cultures of normal human foreskin keratinocytes.
Fatal Hemoptysis in Mitral Stenosis

Fatal massive hemoptysis is described in a patient with moderate mitral stenosis treated supportively. Hemodynamic studies and postmortem examination supported bronchial vein anastomoses as the source of hemorrhage. Review of previous reports emphasizes the necessity of prompt surgical intervention in this syndrome.
Reactions to Affirmative Action: Substance and Semantics

For both theoretical and practical reasons, researchers have sought to map the motivations that underlie people's support for or opposition to affirmative action. In view of the amount of rhetoric surrounding the issues, it is possible that some of the apparent differences in degrees of support come from differences in how the words affirmative action are interpreted. The present investigation shows that the meanings that people ascribe to affirmative action statistically predict their attitudes toward the policy, even after one accounts for demographic and related attitudinal factors. The implications of our findings are important in both applied and conceptual ways.
790 CEPHALEXIN IN CYSTIC FIBROSIS: A PLACEBO-CONTROLLED STUDY

The efficacy of cephalexin monohydrate 50 mg/kg/d was evaluated in a placebo-controlled, double-blind, crossover study of patients with cystic fibrosis. Over a 2 year period, 17 patients with mild-moderate disease were treated for 4 month intervals with either cephalexin or placebo. One patient developed drug-related vulvovaginitis and dropped-out of the study. Although colonization by cephalexin-resistant S. aureus was not observed, 2 patients had an increase in sputum concentration of Ps. aeruginosa during antibiotic therapy. Patients previously colonized with ≥ 106 CFU/ml Ps. aeruginosa of H. influenzae had no alteration in flora. Six of 8 patients colonized with ≥ 106 CFU/ml S. aureus had a decrease in S. aureus concentration to < 104 CFU/ml during treatment with cephalexin. During periods of drug treatment, significantly reduced S. aureus colonization (7% versus 26% of cultures), increased weight gain (1.2 versus 0.2 kg/4 months) and less hospitalizations (2 versus 15) were observed (P < 0.01). There were no differences in pulmonary function tests, chest x-rays, or sputum production during periods of antibiotic or placebo treatment. Cephalexin, when compared to placebo, altered the microbial flora and clinical course of some patients with cystic fibrosis.
Construction of Vertex Operators Using Operator Formalism Techniques

Abstract We derive vertex operators in oscillator form as an application of the conserved charges method developed by Vafa for the operator formalism in higher genus Riemann surfaces. This construction proves to be clear, direct and valid for the bosonic and fermionic strings as well as for twisted strings on orbifolds. We discuss the method and construct vertex operators for the bosonic string moving on Z N orbifolds and for the fermionic string in the NSR formulation.
Existence of periodic solutions for first order differential equations

In this paper we study the periodic boundary value problem for first order differential equations by combining techniques of the theory of differential inequalities, namely the method of upper and lower solutions, and the alternative method for nonlinear problems at resonance. The results obtained are in terms of the behavior of the nonlinear part at infinity.
Prediction and redesign of protein-protein interactions.

Abstract Understanding the molecular basis of protein function remains a central goal of biology, with the hope to elucidate the role of human genes in health and in disease, and to rationally design therapies through targeted molecular perturbations. We review here some of the computational techniques and resources available for characterizing a critical aspect of protein function – those mediated by protein–protein interactions (PPI). We describe several applications and recent successes of the Evolutionary Trace (ET) in identifying molecular events and shapes that underlie protein function and specificity in both eukaryotes and prokaryotes. ET is a part of analytical approaches based on the successes and failures of evolution that enable the rational control of PPI.
Knowledge-based modeling of laser-scanned trees

The increasing availability and power of range scanners has enabled us to scan larger and more complex objects. Trees, however, pose special problems for such scanning. Unlike buildings, trees have relatively more complex geometry, and the scanned tree data is inherently incomplete due to limited scanning resolution and occlusion from leaves and branches. Standard mesh generation techniques often fail because of this inadequate data. Our purpose is to use knowledge about the structure of trees and allometric theory to produce full polygonal meshes from the point clouds obtained from the scans. We aim to produce a mesh that plausibly recreates the tree that was originally scanned, but with extrapolated details that were missing in the point cloud. These surrogate models can then be used in place of the original point clouds for rendering.
Real‐time color B‐scan ultrasonography

The development and early clinical results of a real-time color B-scan ultrasonoscope are described. This instrument uses color to display detailed echo amplitude information more quantitatively than is possible with gray scale. With real time, dynamic changes are seen during the examination. Conversion of the amplitude information into binary coded decimal code permits separation into ten color steps and also eliminates "blooming" of the cathode ray tube, as seen in black and white. Integrated circuitry is used, providing a portable, relatively inexpensive unit. Early clinical work in ophthalmology is illustrated.
Thrombin activity and platelet microparticle formation are increased in type 2 diabetic platelets: a potential correlation with caspase activation.

Diabetics suffer from many complications including a prothrombotic condition. Activated platelet membrane provides an anchor, phosphatidylserine, for the attachment of the prothrombinase complex, which allows increased thrombin formation. This study aimed to further elucidate the interrelationship between coagulation proteins and activated platelets in type 2 diabetic blood. We found that there was a significant increase (30×) in thrombin activity in the type 2 diabetic (ZDF) blood as compared to age-matched (ZL) controls (p<0.001). There was also a significant increase in the number of platelet microparticles in the type 2 diabetic rat compared to the lean control (p<0.001). Further, there were significant increases in caspase-3, -6, and -8 activities in the type 2 diabetic rats as compared to the lean controls (p<0.05). The combination of increased thrombin activity, increased PMP formation and increased caspase activity may contribute to the hypercoagulability of the diabetic blood. These results give more insight into the mechanisms underlying the interrelationship between diabetic platelets and coagulation proteins causing a prothrombotic condition in this patient population at increased risk from thromboembolic events.
Weyl tensor and gravitational entropy.

There is a conjecture due to Penrose that there may be a relation between the Weyl curvature tensor and gravitational entropy. In this paper, this conjecture is studied in the context of a specific model, the Gowdy cosmology. The square of the curvature is calculated as an operator and its expectation values in states of clumped and unclumped gravitons are calculated. The results indicate that the curvature contains information about the entropy of the gravitational field.
Task, Talk, and Text: The Influence of Instructional Conversation on Transitional Bilingual Writers

In this study, we trace the development of ideas explored during reading lessons in children's writings from one transitional bilingual fourth-grade classroom. Using transcripts from audio- and videotaped lessons, we describe the ways in which the reading lessons, designed to facilitate discussions to enhance student reading comprehension, turned into an anchoring activity for the negotiation of joint meaning. They served as a springboard for joint exploration and the generation of intersubjective and co-constructed ideas that bridged the worlds of home and school. We trace the development of these ideas in representative pieces from five student portfolios. Discussions served to display a number of important literacy processes, and ideas and interpretations from these discussions reappeared in the students' writings. This study is of particular interest to educators concerned both with understanding better the influence of classroom discourse on student writing and with finding ways to incorporate studen...
A new approach for removing iron interference from soil nitrate analysis

Abstract The accurate measurement of soil nitrate ( NO 3 − ) is critical for determining rates of nitrogen (N) cycling and potential N losses from ecosystems. Iron (Fe) can interfere with the colorimetric NO 3 − analysis of soil extracts to cause the appearance of anomalously low NO 3 − concentrations. To resolve the interference, imidazole or NH4Cl–DTPA has been recommended to replace NH4Cl–EDTA as the buffer in the analysis. Here we show that phosphate ( PO 4 3 − ) filtration can completely remove Fe interference whereas any of these buffers alone may not. Regardless of which buffer was used, 5.5–55 mg Fe L−1 ferrous iron (Fe2+) interfered with NO 3 − determination in 0.3 mg N– NO 3 − L−1 2 M KCl solutions. Phosphate filtration removed all detectable Fe2+ in 2 M KCl anaerobic soil slurry extracts with high Fe2+ concentrations (25.9 ± 1.7 mg Fe2+ L−1). With each of the three buffers tested, the measured NO 3 − concentrations in the anaerobic soil slurry extracts were significantly higher with PO 4 3 − filtration compared to without filtration. After filtration, the measured NO 3 − concentrations were similar across all three buffers, suggesting that NO 3 − concentrations were accurately measured in PO 4 3 − filtered soil extracts regardless of the buffer used. The Fe:N ratio of Fe interference with NO 3 − determination depended on Fe concentration, NO 3 − concentration, buffer, and cadmium column age, so that the amount of Fe interference that could occur can be difficult to predict. We suggest comparing measured NO 3 − concentrations for unfiltered and PO 4 3 − filtered soil extracts to determine the potential for Fe interference in colorimetric NO 3 − determination as standard additions may not detect all forms of Fe interference.
Economic Evaluation of Three Methods of Treating Urogenital Chlamydial Infections in the Emergency Department

We attempted to determine the economic impact of three alternatives for the treatment of chlamydial infections in the emergency department: a written prescription for 7 days of doxycycline therapy (D-RX); a prepacked 7-day supply of doxycycline (D-ED); or a single 1-g dose of azithromycin (AZI). Data inputs for the model were obtained from both patient experience and literature sources. Primary health outcomes of the model were number of infection relapses. Economic outcomes were costs for initial treatment, treatment of relapses, and treatment of complications of relapse. For every 1000 patients, D-ED and AZI resulted in 21.6 (-10 to -41) and 36.2 (-25 to -63) fewer relapses than D-RX, respectively; AZI resulted in 14.6 (-35 to -4) fewer relapses than D-ED. Total costs were decreased for D-ED and AZI versus D-RX by $18,879 (-$39,000 to -$8000) and $24,039 (-$59,000 to -$10,000), respectively, and AZI resulted in a total cost decrease of $5160 (-$35,000 to +$6000) versus D-ED. Both D-ER and AZI decreased infection relapses and overall health care costs compared with D-RX. Also, AZI resulted in additional decreases in relapses versus D-ED, although the incremental impact on cost was inconclusive.
Improved continuation rate of depo-provera in teen mothers

Abstract BACKGROUND: Poor compliance and high discontinuation rates of Depo-Provera (DP) and other contraceptive methods are major factors in the continuing problem of teen pregnancy. In this study we attempted to determine if providing comprehensive health care for teen mothers and their babies would improve continuation rates of DP. METHODS: Review of clinical data in a Teen-Tot program in regards to DP. Patients who started DP between 1/1/96 and 1/1/99 were included. Teen mothers and their babies receive all their health care in this clinic, supported by State funding. Key elements regarding DP in this clinic are: continuity of care, phone or mail reminders of appointments, free DP for patients without insurance, counseling at each visit and available evening clinic. RESULTS: In the period above a total of 299 (age 13-22) patients were started on DP. 51% were white, 47% black and 2% others. 63% were single, 20% married, 3% cohabitating and 14% undetermined (missing data). 78% had one baby and 22% more than one. A total of 189 patients (63.2%) continued to be compliant after one year of use. 84 patients (28% of total) continued beyond the second year, but the actual percentage of continuation will be higher when patients who are now on DP more than 1 but less than 2 years are included. The most common side effect reported was bleeding/spotting (32%). However only 7 patients (2.3%) discontinued use because of it. CONCLUSION: Continuity of care (same staff and providers on each visit), regular counseling, flexible hours (evening appointments), financial ease (free DP and no visit charge for those without insurance), combined Teen-Tot health visits and regular reminders of appointments help improve compliance and continuation rates in teen mothers leading to better success in prevention of repeat teen pregnancy.
The Cross-Cultural Metric Equivalence of Langner's Twenty-Two Item Index

This study examined the cross-cultural metric equivalence of Langner's twenty-two item index of psychiatric symptoms. Secondary analysis of data from three large-scale surveys was used. Respondents came from three distinct cultural groups: (a) Anglo- American, (b) Vietnamese Chinese, and (c) Mexican-American and Mexican. Factor solutions for each cultural group did not differ in the number of identified factors but did differ in their item composition and consequently in the substantive meaning attributed to each dimension. However, it appears. that the total screening score is primarily measuring a single underlying construct across all three cultural settings.
Structure-volume relationships: volume effects produced by the interaction of Cu(II) with dipeptides

Abstract The volume changes, ΔV, produced by the formation of two types of 1:1 Cu(II):dipeptide complexes were determined dilatometrically. A volume increase of about 11 ml/mole results from the formation of one category of complex in which the Cu(II) is chelated to the terminal amino and carbonyl oxygen of the peptide. A ΔV of about 20 ml/mole results when a tridentated chelate is formed by the coordination of Cu(II) to the terminal amine, the peptide nitrogen and the carboxylate oxygen of the dipeptide; during this process a proton is expelled from the peptide backbone. These volume parameters exhibit a small dependence on the type and location of nonpolar radicals incorporated in the dipeptide. The values for the protonation of the amine radical or of dipeptides exhibited a small dependence on structure, −3.2
Effect of hydrodynamics on reactive mixing in laminar flows

The effects of diffusion and convection on the evolution of reactions in chaotic flows are examined. Direct numerical simulations are applied to compute the evolution of the mixing structure, describe the stretching field, and solve the convection-reaction-diffusion material balance in a periodic, 2-D chaotic flow with an instantaneous, bimolecular reaction: A + B → 2P. These computations demonstrate that the location of the reactive zones in the flow can be predicted from the stretching field. The time-evolution of the concentration profiles approaches an invariant shape when the time scale of the convective and diffusive mixing processes are comparable. Under such conditions, exponential stretching and its consequence, asymptotic directionality, are the mechanisms controlling the evolution of chaotic reactive systems.
Errata for "A harmonic cancellation technique for an ultrasound transducer excited by a switched-mode power converter" [Feb 08 359-367]

In the above titled paper (ibid., vol.55, no. 2, pp. 359-367, Feb 08), two of the figures are incorrect as printed. The corrected figures are presented here.
Contribution of motor vehicle emissions to organic carbon and fine particle mass in Pittsburgh, Pennsylvania: Effects of varying source profiles and seasonal trends in ambient marker concentrations

Abstract We present estimates of the vehicular contribution to ambient organic carbon (OC) and fine particle mass (PM) in Pittsburgh, PA using the chemical mass balance (CMB) model and a large dataset of ambient molecular marker concentrations. Source profiles for CMB analysis are selected using a method of comparing the ambient ratios of marker species with published profiles for gasoline and diesel vehicle emissions. The ambient wintertime data cluster on a hopanes/EC ratio–ratio plot, and therefore can be explained by a large number of different source profile combinations. In contrast, the widely varying summer ambient ratios can be explained by a more limited number of source profile combinations. We present results for a number of different CMB scenarios, all of which perform well on the different statistical tests used to establish the quality of a CMB solution. The results illustrate how CMB estimates depend critically on the marker-to-OC and marker-to-PM ratios of the source profiles. The vehicular contribution in the winter is bounded between 13% and 20% of the ambient OC (274±56–416±72 ng-C m −3 ). However, variability in the diesel profiles creates uncertainty in the gasoline–diesel split. On an OC basis, one set of scenarios suggests gasoline dominance, while a second set indicates a more even split. On a PM basis, all solutions indicate a diesel-dominated split. The summer CMB solutions do not present a consistent picture given the seasonal shift and wide variation in the ambient hopanes-to-EC ratios relative to the source profiles. If one set of source profiles is applied to the entire dataset, gasoline vehicles dominate vehicular OC in the winter but diesel dominates in the summer. The seasonal pattern in the ambient hopanes-to-EC ratios may be caused by photochemical decay of hopanes in the summer or by seasonal changes in vehicle emission profiles.
Congenital Aortic Stenosis: Clinical and Hemodynamic Findings, Surgical Technic, and Results of Operation

Ten years ago congenital aortic stenosis was generally considered to be uncommon and seldom to carry a grave prognosis. The severity of obstruction of left ventricular outflow could not be directly assessed and suitable surgical procedures for its correction were not available. The changing concepts in respect to this malformation are reflected in the series of 30 patients described. The lesion was found to be relatively common and frequently serious. The severity and site of obstruction could be precisely evaluated and a physiologic basis was provided for the selection of patients for operation providing direct exposure of the aortic valve.
Etiologic theories of chronic prostatitis/chronic pelvic pain syndrome

The etiology of chronic prostatitis/chronic pelvic pain syndrome is unknown. Whereas infection causes category I and II prostatitis, the evidence for an ongoing infection in category III patients is lacking. Immunologic, neurologic, and psychologic factors likely play a role in the development and maintenance of symptoms in these men. The traditional concept of pain as a simple response to a noxious stimulus has some merit, but modern research indicates that the response is much more complex, and we must look at a patient’s physiology and psychology to be able to interpret each individual’s pain response. It is some advance in the field to realize that we probably need to look beyond the prostate and address the entire biopsychosocial problem to be able to offer successful treatment to these men.
Process definition formalism maturity levels

Beginning with the observations that process definition formalisms are not very different from general purpose programming languages and that almost every type of programming language has been used as the basis of one or more process definition formalisms, we conclude that the field of process definition formalisms is quite immature. We speculate on the future maturation of this field by proposing a set of maturity levels by which to measure that maturation.
PCB Thermal Via Optimization using Design of Experiments

In order to achieve a low thermal resistance path directly beneath high power dissipating transistors, a thermal via and printed circuit board (PCB) optimization study was performed. The thermal resistance normal to the PCB surface served as the primary reference output, while the calculation parameterization was varied to minimize this thermal resistance. A fractional factorial designed experiment (DOE) was developed using MINITABtrade statistical software for the following thermal via and PCB factors, evaluated at two levels: via diameter, pitch, and barrel thickness as well as PCB top Cu pad area and number of metalized layers. The results for each DOE treatment combination were simulated as a parametric run using a finite volume computational fluid dynamics (CFD) software tool - Icepakreg. Steady-state thermal resistance values, from a power source on top of PCB to the bottom of board, were determined. This demonstrates a methodology of coupling statistical DOE with thermal CFD to efficiently optimize the thermal performance during the early design process
Validation of high-resolution echocardiography and magnetic resonance imaging vs. high-fidelity catheterization in experimental pulmonary hypertension

High-frequency echocardiography and high-field-strength magnetic resonance imaging (MRI) are new noninvasive methods for quantifying pulmonary arterial hypertension (PAH) and right ventricular (RV)...
How to Create and Use Binocular Rivalry

Each of our eyes normally sees a slightly different image of the world around us. The brain can combine these two images into a single coherent representation. However, when the eyes are presented with images that are sufficiently different from each other, an interesting thing happens: Rather than fusing the two images into a combined conscious percept, what transpires is a pattern of perceptual alternations where one image dominates awareness while the other is suppressed; dominance alternates between the two images, typically every few seconds. This perceptual phenomenon is known as binocular rivalry. Binocular rivalry is considered useful for studying perceptual selection and awareness in both human and animal models, because unchanging visual input to each eye leads to alternations in visual awareness and perception. To create a binocular rivalry stimulus, all that is necessary is to present each eye with a different image at the same perceived location. There are several ways of doing this, but newcomers to the field are often unsure which method would best suit their specific needs. The purpose of this article is to describe a number of inexpensive and straightforward ways to create and use binocular rivalry. We detail methods that do not require expensive specialized equipment and describe each method's advantages and disadvantages. The methods described include the use of red-blue goggles, mirror stereoscopes and prism goggles.
Moving the glycoprotein gene of vesicular stomatitis virus to promoter-proximal positions accelerates and enhances the protective immune response

Vesicular stomatitis virus (VSV) is the prototype of the Rhabdoviridae and contains nonsegmented negative-sense RNA as its genome. The 11-kb genome encodes five genes in the order 3′-N-P-M-G-L-5′, and transcription is obligatorily sequential from the single 3′ promoter. As a result, genes at promoter-proximal positions are transcribed at higher levels than those at promoter-distal positions. Previous work demonstrated that moving the gene encoding the nucleocapsid protein N to successively more promoter-distal positions resulted in stepwise attenuation of replication and lethality for mice. In the present study we investigated whether moving the gene for the attachment glycoprotein G, which encodes the major neutralizing epitopes, from its fourth position up to first in the gene order would increase G protein expression in cells and alter the immune response in inoculated animals. In addition to moving the G gene alone, we also constructed viruses having both the G and N genes rearranged. This produced three variant viruses having the orders 3′-G-N-P-M-L-5′ (G1N2), 3′-P-M-G-N-L-5′ (G3N4), and 3′-G-P-M-N-L-5′ (G1N4), respectively. These viruses differed from one another and from wild-type virus in their levels of gene expression and replication in cell culture. The viruses also differed in their pathogenesis, immunogenicity, and level of protection of mice against challenge with wild-type VSV. Translocation of the G gene altered the kinetics and level of the antibody response in mice, and simultaneous reduction of N protein expression reduced replication and lethality for animals. These studies demonstrate that gene rearrangement can be exploited to design nonsegmented negative-sense RNA viruses that have characteristics desirable in candidates for live attenuated vaccines.
Easter Island: historical anecdote or warning for the future?

Two standard solutions for the ‘Malthusian Trap’ involve institutional reforms and technological progress. Using Easter Island as an example, we investigate the hypothetical role that technological progress and population management reform might have played in preventing the collapse of the island’s civilization. The model includes a composite manufactured good and a composite harvested renewable resource. Fertility is assumed to rise with per capita income. The resource’s carrying capacity and intrinsic growth rate as well as labor’s harvesting productivity are subject to technological progress. Fertility is subject to population management reform. The model yields a system of two simultaneous, nonlinear, non-autonomous differential equations. We first study the system’s steady states. The system is then parameterized for Easter Island and its comparative dynamics are investigated in simulations. We find that technological progress can generate large fluctuations in population, renewable resources, and per capita utility, sometimes resulting in system collapse. With high fertility rates, the population and the resource vanish. None of the simulations investigated here exhibit a constantly growing per capita utility over time. Finally, we evaluate the applicability of these results to contemporary societies. © 2000 Elsevier Science B.V. All rights reserved.
The Structure of Scientific Arguments by Secondary Science Teachers: Comparison of experimental and historical science topics

Just as scientific knowledge is constructed using distinct modes of inquiry (e.g. experimental or historical), arguments constructed during science instruction may vary depending on the mode of inquiry underlying the topic. The purpose of this study was to examine whether and how secondary science teachers construct scientific arguments during instruction differently for topics that rely on experimental or historical modes of inquiry. Four experienced high-school science teachers were observed daily during instructional units for both experimental and historical science topics. The main data sources include classroom observations and teacher interviews. The arguments were analyzed using Toulmin's argumentation pattern revealing specific patterns of arguments in teaching topics relying on these 2 modes of scientific inquiry. The teachers presented arguments to their students that were rather simple in structure but relatively authentic to the 2 different modes. The teachers used far more evidence in teachi...
Texture-based feature tracking for effective time-varying data visualization

Analyzing, visualizing, and illustrating changes within time-varying volumetric data is challenging due to the dynamic changes occurring between timesteps. The changes and variations in computational fluid dynamic volumes and atmospheric 3D datasets do not follow any particular transformation. Features within the data move at different speeds and directions making the tracking and visualization of these features a difficult task. We introduce a texture-based feature tracking technique to overcome some of the current limitations found in the illustration and visualization of dynamic changes within time-varying volumetric data. Our texture-based technique tracks various features individually and then uses the tracked objects to better visualize structural changes. We show the effectiveness of our texture-based tracking technique with both synthetic and real world time-varying data. Furthermore, we highlight the specific visualization, annotation, registration, and feature isolation benefits of our technique. For instance, we show how our texture-based tracking can lead to insightful visualizations of time-varying data. Such visualizations, more than traditional visualization techniques, can assist domain scientists to explore and understand dynamic changes.