cssi/SciSciGPT-SciSciNet huggingface dataset:
Methylation as a Crucial Step in Plant microRNA Biogenesis

Methylation on the base or the ribose is prevalent in eukaryotic ribosomal RNAs (rRNAs) and is thought to be crucial for ribosome biogenesis and function. Artificially introduced 2'-O-methyl groups in small interfering RNAs (siRNAs) can stabilize siRNAs in serum without affecting their activities in RNA interference in mammalian cells. Here, we show that plant microRNAs (miRNAs) have a naturally occurring methyl group on the ribose of the last nucleotide. Whereas methylation of rRNAs depends on guide RNAs, the methyltransferase protein HEN1 is sufficient to methylate miRNA/miRNA* duplexes. Our studies uncover a new and crucial step in plant miRNA biogenesis and have profound implications in the function of miRNAs.
Citizen Input and Professional Responsibility

Input to planning desicions comes from many sources, including public meetings and citizen opinion surveys. Often data from such sources are in conflict with each other as well as at odds with professional recommendations, and planners and public officials must evaluate the veracity of dif ferent inputs. This article illustrates how citizen input can vary depending upon the method used to obtain it, discusses the reasons for these differences, and sug gests factors that must be considered when using citizen input in practice and when educating planning students. The article holds that planners have an obliga tion to face up to tough, possibly unpop ular planning decisions that cannot be derived by averaging out citizen opinion.
Pulmonary rehabilitation in patients undergoing lung-volume reduction surgery.

Abstract Bartels MN, Kim H, Whiteson JH, Alba AS. Pulmonary rehabilitation in patients undergoing lung-volume reduction surgery. Chronic obstructive pulmonary disease (COPD) is the most common form of primary pulmonary disability. Few effective treatment options exist for it, but recently, lung-volume reduction surgery (LVRS) has been shown to be effective in selected patients with emphysema. Pulmonary rehabilitation is an integral part of the preparation for and recovery from the procedure and has significant benefit in helping to improve the quality of life and conditioning of patients with COPD who undergo LVRS. Overall Article Objectives (a) To describe the role of pulmonary rehabilitation in LVRS, (b) to understand the components of a comprehensive pulmonary rehabilitation program, and (c) to describe the effects of a pulmonary rehabilitation program.
Signature of the transition zone in the tomographic results extracted through the Eigenfunctions of the two‐point correlation

Seismic tomography (Tanimoto 1990, Su & Dziewonski 1991 and Masters et al. 1992) has provided detailed three-dimensional map of the shear wave velocity in the Earth's mantle. These tomographic results when characterized by the radial correlation function (Jordan et al. 1993) shows no signature of the mantle transition zone. The radial correlation function and associated radial correlation length are subsets of the entire two-point correlation and therefore here we propose an optimal characterization of the two-point correlation in terms of its eigenfunctions. It is shown that the eigenrepresentation of the tomographic data converges rapidly and that the most energetic eigenfunctions reveal the signature of the mantle transition zone.
Nanoprobing of α-synuclein misfolding and aggregation with atomic force microscopy

Atomic force microscopy (AFM) force spectroscopy is a technique with broad nanomedical applications, widely used for the characterization of molecular interactions on the nanoscale. Here we test this technique to evaluate compounds for influencing the protein aggregation process. The results demonstrate that Zn 2+ or Al 3+ cations bring about a dramatic increase of α-synuclein interactions in unfavorable conditions for α-synuclein misfolding (neutral pH). We did not observe the effect of dopamine at favorable conditions for α-synuclein misfolding (acidic pH). We also found that electrostatic interactions do not play a significant role at acidic pH. These findings are generally in line with previous studies by various techniques. The high sensitivity of AFM force spectroscopy as well as its ability to test compounds for the same experimental system makes AFM an efficient nanotool for rapid analysis of compounds inhibiting early protein aggregation studies and quantitative selection of potential therapeutics for neurodegenerative diseases. From the Clinical Editor: Atomic force microscopy is used to interrogate the influence of cations and α-synuclein on the protein aggregation process. The report illustrates an application of AFM to unravel the potential of novel therapeutics on early protein aggregation
Assessing results of the Alameda project

Abstract This note assesses the Alameda Project, a successful experiment conducted in California and designed to restore foster children to their home or to provide alternative continuous care. The study is examined critically against research which indicates that the majority of foster children come from economically disadvantaged homes and that restoration to homes in which the environmental conditions are not adequately improved often results in the recurrence of problems or the development of new problems.
Carbon-13 Chemical Shift Tensors and Molecular Conformation of Anisole

The first direct measurement of the ortho steric effect of the methoxy group on the 13C chemical shifts in anisole is reported. The ortho steric effect on the isotropic 13C chemical shifts was obta...
Concentration Polarization of Interacting Solute Particles in Cross-Flow Membrane Filtration

A theoretical approach for predicting the influence of interparticle interactions on concentration polarization and the ensuing permeate flux decline during cross-flow membrane filtration of charged solute particles is presented. The Ornstein-Zernike integral equation is solved using appropriate closures corresponding to hard-spherical and long-range solute-solute interactions to predict the radial distribution function of the solute particles in a concentrated solution (dispersion). Two properties of the solution, namely the osmotic pressure and the diffusion coefficient, are determined on the basis of the radial distribution function at different solute concentrations. Incorporation of the concentration dependence of these two properties in the concentration polarization model comprising the convective-diffusion equation and the osmotic-pressure governed permeate flux equation leads to the coupled prediction of the solute concentration profile and the local permeate flux. The approach leads to a direct quantitative incorporation of solute-solute interactions in the framework of a standard theory of concentration polarization. The developed model is used to study the effects of ionic strength and electrostatic potential on the variations of solute diffusivity and osmotic pressure. Finally, the combined influence of these two properties on the permeate flux decline behavior during cross-flow membrane filtration of charged solute particles is predicted.
Experimental and numerical conversion of liquid heptane to syngas through combustion in porous media

The conversion of liquid heptane to syngas in a porous medium reactor consisting of a packed bed of alumina pellets is investigated numerically and experimentally. In experiments, the exhaust gas was analyzed for hydrogen, carbon monoxide, carbon dioxide, methane, and hydrocarbon species over equivalence ratios from 1.4 to 3.8 and a range of mixture inlet velocities. The efficiency of the noncatalytic fuel reformer regarding hydrogen production, carbon monoxide production and energy conversion is assessed. At constant inlet velocity, hydrogen production increases with increasing equivalence ratio, whereas hydrogen conversion efficiency reaches its peak value around an equivalence ratio of 3.0. Tests at a constant equivalence ratio of 2.5 show that conversion efficiency increases with mixture inlet velocity, and experimental values in excess of 80% are obtained for the highest tested velocity of 80 cm/s. Similar trends are observed for carbon monoxide conversion and energy efficiencies, where peak values exceed 90% and 80%, respectively. Some discrepancies are noted between the experimental and numerical results in the ultrarich regime. Overall, the results indicate favorable conditions for fuel reforming between equivalence ratios of 2.5 and 3.5 and show that the inlet velocity has a significant effect on the performance of noncatalytic fuel reforming. Substantial efficiency gains are observed for increased inlet velocities, which are attributed to increases in the reactor temperature.
Support for repetitive transactions and ad hoc queries in System R

System R supports a high-level relational user language called SQL which may be used by ad hoc users at terminals or as an embedded data sublanguage in PL/I or COBOL. Host-language programs with embedded SQL statements are processed by the System R precompiler which replaces the SQL statements by calls to a machine-language access module. The precompilation approach removes much of the work of parsing, name binding, and access path selection from the path of a running program, enabling highly efficient support for repetitive transactions. Ad hoc queries are processed by a similar approach of name binding and access path selection which takes place on-line when the query is specified. By providing a flexible spectrum of binding times, System R permits transaction-oriented programs and ad hoc query users to share a database without loss of efficiency.System R is an experimental database management system designed and built by members of the IBM San Jose Research Laboratory as part of a research program on the relational model of data. This paper describes the architecture of System R, and gives some preliminary measurements of system performance in both the ad hoc query and the “canned program” environments.
5-hydroxytryptamine 2C receptors tonically augment synaptic currents in the nucleus tractus solitarii.

The nucleus tractus solitarii (nTS) is the primary termination and integration point for visceral afferents in the brain stem. Afferent glutamate release and its efficacy on postsynaptic activity within this nucleus are modulated by additional neuromodulators and transmitters, including serotonin (5-HT) acting through its receptors. The 5-HT2 receptors in the medulla modulate the cardiorespiratory system and autonomic reflexes, but the distribution of the 5-HT2C receptor and the role of these receptors during synaptic transmission in the nTS remain largely unknown. In the present study, we examined the distribution of 5-HT2C receptors in the nTS and their role in modulating excitatory postsynaptic currents (EPSCs) in monosynaptic nTS neurons in the horizontal brain stem slice. Real-time RT-PCR and immunohistochemistry identified 5-HT2C receptor message and protein in the nTS and suggested postsynaptic localization. In nTS neurons innervated by general visceral afferents, 5-HT2C receptor activation increased solitary tract (TS)-EPSC amplitude and input resistance and depolarized membrane potential. Conversely, 5-HT2C receptor blockade reduced TS-EPSC and miniature EPSC amplitude, as well as input resistance, and hyperpolarized membrane potential. Synaptic parameters in nTS neurons that receive sensory input from carotid body chemoafferents were also attenuated by 5-HT2C receptor blockade. Taken together, these data suggest that 5-HT2C receptors in the nTS are located postsynaptically and augment excitatory neurotransmission.
Developing a concept extraction technique with ensemble pathway

In this paper, we describe our Concept Extraction technique for Educational Digital libraries (CEED) which applies Conditional Random Fields (CRFs) to extract concepts from the Ensemble Pathway collection. In addition, we discuss how we implement RESTful APIs for concept extraction.
Patient-centric dose equivalency pilot study of incobotulinumtoxin a (xeomin) vs . abobotulinumtoxin a (dysport) in the treatment of glabellar frown lines

Aim: Incobotulinumtoxin A (xeomin) has been proposed as an alternative to abobotulinumtoxin A (dysport) and onabotulinumtoxin A (Botox) in the treatment of glabellar frown lines. A recent study is comparing abobotulinumtoxin A and onabotulinumtoxin A revealed equivalent efficacy with a dose conversion ratio of 2.5:1. We sought to establish effectiveness and dosing equivalency of incobotulinumtoxin A vs. abobotulinumtoxin A. Methods: Inclusion criteria for this pilot study included patients of a single surgeon (LAC) who had previously received a constant dose of abobotulinumtoxin A over at least four consecutive treatment sessions for the previous 12 months to achieve an 85-90% elimination of dynamic glabellar frown lines. The primary outcome sought dose comparison between established maintenance abobotulinumtoxin A dosing and incobotulinumtoxin A first-time dosing. A 2:1 conversion (abobotulinumtoxin A: incobotulinumtoxin A) was chosen in most patients. Secondary outcomes were patient-reported onset of effect, physician-assessed effect at 10-12 weeks, pain associated with administration, and patient perceived need for re-treatment at 2 weeks. Results: A total of 32 subjects were included. The mean dose of incobotulinumtoxin A was 17.1 units (± 6.1, the median dose 20 units). The mean dose of abobotulinumtoxin A was 27.6 (± 11.7, the median dose 27.5 units). The mean difference in treatment units was -10.5 (95% confidence interval, P vs. 90.3% (± 1.8) with abobotulinumtoxin A ( P Conclusion: We found incobotulinumtoxin A at 17.1 (± 6.1) units to be less effective than abobotulinumtoxin A at 27.6 (± 11.7) units in the treatment of glabellar frown lines at 10-12 weeks postadministration. Dosing was less predictable than dosing associated with abobotulinumtoxin A treatment. Larger, randomized controlled trials are indicated to further delineate these differences and to clarify whether this difference from previously published incobotulinumtoxin A dosing may have been due to the small sample size.
Specificity of the stimulation by quinones of direct oxidation of glucose by brain slices.

Abstract Approximately equal amounts of 14 CO 2 are produced when guinea-pig brain slices are incubated with either [ I - 14 C]glucose or [6- 14 C]glucose. If the following are added to the incubation medium at about 10 −5 M , 14 CO 2 production from [1- 14 C]glucose increases 2- to 3-fold while that from [6- 14 C]glucose remains relatively unchanged: menadione; 2,3-dimethyl-1,4-naphthoquinone; 2-methyl-5,6,7,8-tetrahydro-1,4-naphthoquinone; plumbagin; 2-methyl-4α,5,8,8α-tetrahydro-1,4-naphthoquinone; trimethylquinone. Twelve other structurally related quinones, including vitamin K 1 and coenzyme Q 10 , do not show this effect. A few are inhibitory. The results indicate the existence of some enzyme-cofactor relationship involving quinones or naphthoquinones of suitable configuration. The necessary configuration around the quinone nucleus is discussed in the light of these results.
Approximate Formulas for Time in Nearly Circular Orbits with Drag

In this paper we seek approximate closed-form solutions for the flight time in terms of the true anomaly for a satellite in a high near-circular orbit that decays as a result of atmospheric drag. Solutions of this problem are attempted based on three models that approximate the atmospheric density. For the first model and in certain special cases of the other two models, solutions are found that compare favorably with numerical simulations.
Facile synthesis of 1,1-[2H2]-2-methylaminoethane-1-sulfonic acid as a substrate for taurine α ketoglutarate dioxygenase (TauD)

Abstract Taurine α-ketoglutarate dioxygenase (TauD) is an archetypal α-ketoglutarate-dependent non-heme iron oxygenase. Here, we report a practical five-step synthetic route to 1,1-dideutero-2-methylaminoethanesulfonic acid hydrochloride, a useful alternative substrate for the characterization of deuterium kinetic isotope effects on TauD.
Factors in the Cross-Cultural Patterning of Male Homosexuality: A Reappraisal of the Literature

Cross-cultural studies of homosexuality have focused either on homosexual behavior or on a specific characteristic such as transvestism that has been associated with homosexuality in some societies...
Detection of arboviral RNA directly from mosquito homogenates by reverse-transcription-polymerase chain reaction.

Many arthropod-borne viruses (arboviruses) are important human pathogens medically. The development of an effective technique to detect the viruses by using nucleic acid amplification, such as polymerase chain reaction (PCR), improves not only clinical diagnosis but also virologic surveillance of mosquito vectors in the field. In this study, the development of an improved and simplified assay is described for detection of mosquitoes infected with eastern equine encephalitis (EEE) virus, Cache Valley (CV), and California (CAL) serogroup viruses from field-collected mosquito pools. As little as 5 μl of homogenate from mosquito pools was used in the reverse transcription (RT) reaction followed by the use of three sets of specific primers for the PCR. Positive pools were determined by finding PCR bands of the expected size for each arbovirus. The confirmation and identification of Bunyaviruses was done by sequencing the PCR product. In 1999, West Nile virus (WNV) was identified as the etiologic agent of an outbreak of human encephalitis in New York City. It is shown that this protocol is also able to detect West Nile viral RNA in a pool of 100 mosquitoes containing one infected mosquito.
Cardiovascular Toxicities of Cancer Chemotherapy

Cancer chemotherapy has improved over the years with the advent of newer agents, including more targeted chemotherapeutic drugs, resulting in better patient survival. However, with continued use and patient exposure to these drugs, important cardiovascular adverse effects are becoming realized, such as left ventricular dysfunction and heart failure, myocardial ischemia, hypertension, arrhythmias, and pulmonary arterial hypertension. In this article, we review the most common cardiovascular toxicities and their related pathophysiology that occur with the use of these agents.
Recoverability of modular systems

In [1] GOSTELOW-VAN WEERT, it was shown that processes can be described by Petri-nets (PN). In this note we will demonstrate a way of designing programs using Petri-nets as a way of describing the desired behavior. This approach makes it possible to utilize all the theoretic knowledge developed for PN and thus provides a powerful tool for program design. In an example of this approach we show how to design a recoverable program. This design is based on a study of recoverable PN's presented in [2], [3], [4] and [5].In this note, we will not deal with the code itself, but with the structural organization of the programs. Our approach is based on an hierarchical, top-bottom, modular design. At each level a description of the desired system behavior is given. This description is then modeled by a PN and analyzed using the theory developed for PN's.This analysis allows one to check for, among other things, properties of the systems such as recoverability, proper termination, etc. These properties are inherently structural and not dependent on internal module semantics.
Vapour-grown 1.3 μm InGaAsP/InP avalanche photodiodes

A novel planar InGaAsP/InP avalanche photodiode structure prepared by vapour-phase epitaxy is described. Avalanche gain up to 20 at 1.3 μm and at reverse breakdown of 65 V has been measured.
The L Radiation from Sulphur

The $L$-emission band from a sulphur target has been studied spectrophotometrically, and the intensity contour of the band has been deduced. The essential features consist of a strong peak at 149 ev, less pronounced structures at about 158 ev, and a broad peak or "tail" around 136 ev, in substantial agreement with previous studies. In contrast with the corresponding bands from the metallic elements of the second row of the periodic table, the drop in intensity on the high energy side of the band occurs gradually. Because of this fact, and perhaps also because of insufficient resolving power, the ${L}_{\mathrm{II}}$ and ${L}_{\mathrm{III}}$ edges have not been separated. A tentative interpretation has been given for the main observed features. No trace of the ${L}_{\mathrm{I}}\ensuremath{-}{L}_{\mathrm{III}}$ transition has been found.
Electrochemical Method for Detecting Hydrogen Peroxide–Catalase-Treated Milk

Abstract The electrochemical determination of oxygen in milk provides a quick, practical, and simple means of detecting hydrogen peroxidecatalase-treated milk. A fresh, raw milk containing more than 15ppm oxygen should be viewed with suspicion. Severe agitation of milk or flushing with gases reduces the oxygen differential between treated and untreated milks, but under realistic field conditions agitation is unlikely to reduce the level in treated milk below 15ppm oxygen. Attempts to mask treatments in large volumes of milk by gassing or excessive agitation would be technically complicated, time consuming, and uneconomical.
Ultrafast transient white-light absorption spectroscopy of novel materials for optical limiting

The excited state absorption of lead phthalocyanine is investigated using ultrafast transient white light absorption spectroscopy. Singlet state absorption features are identified on the basis of time. Increases in optical density up to 1 in the near infrared region of 900 nm to 1.1 micrometers are observed by pumping at 800 nm. In addition, several artifacts of this technique are discussed, with an aim towards improvements. In particular, self-pumping of the sample via the supercontinuum probe is observed and investigated.© (1999) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Thoracoscopic thymectomy for myasthenia gravis

SummaryPatients with myasthenia gravis and an enlarged thymus commonly undergo surgical thymectomy through a sternotomy. The recent development of laparoscopic techniques and the rapid return to baseline patient function after laparoscopic surgery has led to the reevaluation of the surgical approach. Recently, the mediastinum has been approached thoracoscopically, through much smaller incisions than traditional thoracotomy or sternotomy. We have applied the thoracoscopic approach to the thymus in a patient with myasthenia gravis and review the related literature.
Pre-treatment of synthetic elastomeric scaffolds by cardiac fibroblasts improves engineered heart tissue

Native myocardium consists of several cell types, of which approximately one-third are myocytes and most of the nonmyocytes are fibroblasts. By analogy with monolayer culture in which fibroblasts were removed to prevent overgrowth, early attempts to engineer myocardium utilized cell populations enriched for cardiac myocytes (CMs; ∼80–90% of total cells). We hypothesized that the pre-treatment of synthetic elastomeric scaffolds with cardiac fibroblasts (CFs) will enhance the functional assembly of the engineered cardiac constructs by creating an environment supportive of cardiomyocyte attachment and function. Cells isolated from neonatal rat ventricles were prepared to form three distinct populations: rapidly plating cells identified as CFs, slowly plating cells identified as CMs, and unseparated initial population of cells (US). The cell fractions (3 × 106 cells total) were seeded into poly(glycerol sebacate) scaffolds (highly porous discs, 5 mm in diameter × 2-mm thick) using Matrigel™, either separately (CM or CF), concurrently (US), or sequentially (CF pre-treatment followed by CM culture, CF + CM), and cultured in spinner flasks. The CF + CM group had the highest amplitude of contraction and the lowest excitation threshold, superior DNA content, and higher glucose consumption rate. The CF + CM group exhibited compact 100- to 200-μm thick layers of elongated myocytes aligned in parallel over layers of collagen-producing fibroblasts, while US and CM groups exhibited scattered and poorly elongated myocytes. The sequential co-culture of CF and CM on a synthetic elastomer scaffold thus created an environment supportive of cardiomyocyte attachment, differentiation, and contractile function, presumably due to scaffold conditioning by cultured fibroblasts. When implanted over the infarcted myocardium in a nude rat model, cell-free poly(glycerol sebacate) remained at the ventricular wall after 2 weeks of in vivo, and was vascularized. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res 2008
Beyond the Looking Glass: Bringing Students into the Conversation of Historical Inquiry

Abstract This article is an examination of the divide between high school students' conceptions of historical inquiry and those articulated in current proposals for curricular and instructional reform. The author argues that students acquire stubborn misconceptions in the course of schooling about what constitutes historical knowledge; specifically, students learn that historical truth is taught by teacher and text, and that photography and film provide a mirror of the facts. Such learning impedes students' grasp of the contextualized, creative, intentioned, and tentative nature of historical interpretation and representation, and so constitutes a significant obstacle to reform. Drawing upon data from a case study of one class that seemingly exemplified the spirit of reform, upon theoretical perspectives of inquiry and representation, and upon empirical research about teaching and learning across the curriculum, the author maintains that successful reform requires instruction that both shifts the locus of...
Relevance of Accelerator/Storage Ring Technological Developments to U.S.A. Science and Technology--Past, Present, and Future

In summary, the invention and development of particle accelerators and the associated technology has had a profound impact upon the progress which has been achieved in U.S. science and technology. It has been a joint effort of those who build accelerators and those who use them, each playing a vital role. The contributions from the past by the accelerator community are continuing now and there is every reason to believe that they will continue in the future. The accelerator community can and should be proud of their contributions.
Integrating Curriculum, Instruction, and Assessment in Project-Based Instruction: A Case Study of an Experienced Teacher

This case study of a teacher who engaged his students in inquiry within a technologically rich classroom was conducted over 5 weeks, including 15 regularly scheduled classes. Data include extensive teacher interviews, e-mail, and artifacts such as class notes, curriculum guides, and handouts. A retrospective analysis methodology was utilized to address what Barron et al. (1998), called the “major hurdles” in implementing project-based curricula: the simultaneous changes in curriculum, instruction, and assessment practices. In addition, a framework developed by the National Research Council’s “How People Learn” was employed to provide detail on the nature of knowledge, learner, assessment, and community centeredness of the project-based unit. Finally, the classroom environment created during a unit of astronomy was analyzed and five principles emerged: the sense of a project, the development of independent individuals, creation of a global community of learners, a cyclic nature of instruction emphasizing conceptual and procedural understanding, and the utilization of distributedexpertise.
Helix–coil transition in heterogeneous chains. II. DNA model

Melting curves are calculated for infinitely long DNA-like random copolymers composed of AT and GC pairs of nucleotides. The entropy of random coil rings formed on melting is explicitly included through use of the Jacobson-Stockmayer ring-weighting factors. Transition curves are calculated for values of the cooperativity parameter σ in the range 10−2 ⩽ σ ⩽ 10−4. Ninety percent of the melting occurs in ca. 0.2°C for σ ⩽ 10−3 regardless of the mole fraction of GC. We conclude that observed breadths of thermal denaturation curves for native DNAs result from a superposition of essentially all-or-none melting of various regions of the molecule. It is argued that refined approximations to the ring-weighting factors are probably not important when compared with the effects produced by long-range base sequence correlations which are known to occur in native DNA.
A Spectroscopic and Thermodynamic Study of Porphyrin/DNA Supramolecular Assemblies

Assemblies of trans-bis(N-methylpyridinium-4-yl)diphenylporphine ions on the surface of calf thymus DNA have been studied using several spectroscopic techniques: absorbance, circular dichroism, and resonance light scattering. The aggregation equilibrium can be treated as a two-state system-monomer and assembly-each bound to the nucleic acid template. The aggregate absorption spectrum in the Soret region is resolved into two bands of Lorentzian line shape, while the DNA-bound monomer spectrum in this region is composed of two Gaussian bands. The Beer-Lambert law is obeyed by both porphyrin forms. The assembly is also characterized by an extremely large, bisignate induced circular dichroism (CD) profile and by enhanced resonance light scattering (RLS). Both the CD and RLS intensities depend linearly on aggregate concentration. The RLS result is consistent with a model for the aggregates as being either of a characteristic size or of a fixed distribution of sizes, independent of total porphyrin concentration or ionic strength. Above threshold values of concentration and ionic strength, the mass action expression for the equilibrium has a particularly simple form: K' = cac-1; where cac is defined as the "critical assembly concentration."offe dependence of the cac upon temperature and ionic strength (NaCl) has been investigated at a fixed DNA concentration. The value of the cac scales as the inverse square of the sodium chloride concentration and, from temperature dependence studies, the aggregation process is shown to be exothermic.
Planar biaxial creep and stress relaxation of the mitral valve anterior leaflet.

A fundamental assumption in mitral valve (MV) therapies is that a repaired or replaced valve should mimic the functionality of the native valve as closely as possible. Thus, improvements in valvular treatments are dependent on the establishment of a complete understanding of the function and mechanical properties of the native normal MV. In a recent study [Grashow et al. ABME 34(2), 2006] we demonstrated that the planar biaxial stress–strain relationship of the MV anterior leaflet (MVAL) exhibited minimal hysteresis and a stress–strain response independent of strain rate, suggesting that MVAL could be modeled as a “quasi-elastic” material. The objective of our current study was to expand these results to provide a more complete picture of the time-dependent mechanical properties of the MVAL. To accomplish this, biaxial stress-relaxation and creep studies were performed on porcine MVAL specimens. Our primary finding was that while the MVAL leaflet exhibited significant stress relaxation, it exhibited negligible creep over the 3-h test. These results furthered our assertion that the MVAL functionally behaves not as a linear or non-linear viscoelastic material, but as an anisotropic quasi-elastic material. These results appear to be unique in the soft tissue literature; suggesting that valvular tissues are unequalled in their ability to withstand significant loading without time-dependent material effects. Moreover, insight into these specialized characteristics can help guide and inform efforts directed toward surgical repair and engineered valvular tissue replacements.
Magnetic anisotropy of the nitro group studied by nuclear magnetic resonance

The observed proton magnetic resonance shifts of ortho-methyl-protons in o-methyl-nitrobenzene derivatives have a regular dependence on the rotational angle of the nitro group around the C-N bond. The nature of this dependence has been mainly attributed to the magnetic anisotropy of the nitro group. From this dependence and with several reasonable assumptions, the principal magnetic susceptibilities of a nitro group have been calculated.
Intestinal absorption and metabolism of 6-mercaptopurine in the rat small intestine

The intestinal absorption of 6-mercaptopurine was examined in the rat by in vitro and in situ techniques for the purpose of establishing absorption characteristics which might explain the poor systemic oral availability of this drug. Experiments were designed to evaluate the significance of intestinal metabolism and active secretion processes. Since mucosal/serosal drug concentration gradients across in vitro segments were not significantly different (P > 0.05) for everted and noneverted preparations, with values of 1.21 ± 0.27 and 0.91 ± 0.12, respectively, it was concluded that active secretion or absorption mechanisms were absent. Varying the concentration of 6-mercaptopurine from 0.24 to 5.88 mM demonstrated saturability of the biotransformation of 6-mercaptopurine to 6-thiouric acid with a maximum rate of 1.6 × 10−5 mmoles per min per g for jejunal portions. Distal segments displayed 85% higher rates of biotransformation at concentrations of 1.47mM. Inclusion of allpurinol (2mM) completely inhibited biotransformation. With in situ loops perfused with 1.47mM drug, collection of mesentery blood showed that absorption rates of 6-thiouric acid were 0.67 that of the parent drug.
Comparison of observed gale radius statistics

Forecasts of tropical cyclone track and intensity have long been used to characterize the evolution and expected threat from a tropical storm. However, in recent years, recognition of the contributions of subtropical cyclogenesis to tropical storm formation and the process of extratropical transition to latter stages of the once-tropical storm’s lifecycle have raised awareness about the importance of storm structure. Indeed, the structure of a cyclone determines the distribution and intensity of the significant weather associated with that storm. In this study, storm structure is characterized in terms of significant wind radii. The radii of tropical storm, damaging, and hurricane-force winds, as well as the radius of maximum winds are all analyzed. These wind radii are objectively derived from the H*Wind surface wind analysis system. Initially, six years of these data are examined for consistency with previous studies. Having ascertained that the H*Wind radii are realistic, detailed comparisons are performed between the H*Wind and NHC Best Track wind radii for two years (2004 and 2005) of North Atlantic tropical storm and hurricane cases. This intercomparison reveals an unexpected bias: the H*Wind radii are consistently larger than the NHC Best Track for all but the smallest and least intense storms. Further examination of the objectively-determined H*Wind tropical storm force wind radius data compared to subjectively-determined radii for the same storm times demonstrates that the objective wind radii are underestimating the extent of the tropical storm force wind area. Since the objective H*Wind radii are large compared to the NHC Best Track – and yet underestimate the area of tropical storm force winds – this argues for further examination of the methods used to ascertain these significant wind radii.
Differentiating Psychotic Patients From Nonpsychotic Patients With the MMPI-2 and Rorschach

The goal of this study was to examine the incremental validity and the clinical utility of the Minnesota Multiphasic Personality Inventory-2 (MMPI-2; (Butcher, Dahlstrom, Graham, Tellegen, & Kaemmer, 1989) and Rorschach (Rorschach, 1942) with regard to differential diagnosis in a sample of adult inpatients with a primary psychotic disorder or a primary mood disorder without psychotic features. Diagnostic efficiency statistics have suggested that the Rorschach Perceptual Thinking Index (PTI; Exner, 2000a, 2000b) was better than MMPI-2 scales in discriminating psychotic patients from nonpsychotic patients. We compared the 84% overall correct classification rate (OCC) for the PTI to an OCC of 70% for the MMPI-2 scales. Adding the MMPI-2 scales to the PTI resulted in a decrease in OCC of 1%, whereas adding the PTI to the MMPI-2 resulted in an increase in OCC of 14%. Sensitivity, specificity, positive predictive power, negative predictive power, and kappa were equal or higher with only the PTI in the model.
Measuring the coordination number and entropy of a 3D jammed emulsion packing by confocal microscopy.

Jammed matter is by definition impenetrable to light, such that little is known about the geometry of jammed systems. Using confocal microscopy to image an emulsion in 3D, we first explain the origin of the enhanced fluorescence at the droplet contacts and then determine the contact network inside the model frictionless system. This enables the experimental determination of the average coordination number $⟨Z⟩$ which agrees with the isostatic predicted value of $⟨Z⟩\ensuremath{\approx}6$. Furthermore, we calculate the entropy of the packing from the network of contacts.
Disulfiram-Like Reactions With Newer Cephalosporins: Cefmenoxime

A 54-year-old woman with recurrent adenocarcinoma of the uterus was treated with new third-generation cephalosporin, cefmenoxime, for a urinary tract infection. She received an alcohol-containing tylenol elixir while receiving the drug on two occasions. A disulfiram-like reaction was noticed each time. Such reactions have been described in patients receiving certain drugs such as 5-nitroimidazoles, nitrofurans, sulfonylureas and certain newer cephalosporins with a methyltetrazolethiol side chain. This is the first report of a disulfiram-like reaction with cefmenoxime. The mechanism, causes, and significance of disulfiram-like reactions are discussed.
The effect of continuous or pulsatile administration of oxytocin to ewes at 126 to 136 days' gestation on myometrial activity and fetal oxygenation.

Oxytocin was infused either continuously or in pulses to pregnant ewes to compare the responses of myometrial activity (contractures) and changes in fetal arterial PO 2 . Group 1 ( n = 5) was infused with saline solution throughout the experiment. In group 2 ( n = 5) oxytocin was infused continuously (160 μU · kg -1 · min -1 ) for 7 days whereas group 3 ( n = 5) ewes received 960 μU · kg -1 · min -1 for 5 minutes every 30 minutes for 7 days. Contracture frequency increased in both oxytocin-infused groups. With continuous infusion contracture frequency returned to preinfusion levels during the last 4 days of infusion, whereas with pulsatile infusion contracture frequency remained increased throughout the infusion period. Fetal arterial PO 2 was decreased throughout the 7 days of infusion in both oxytocin-infused groups. Pulsatile group fetal arterial PO 2 levels remained decreased after the oxytocin infusion was stopped. These findings show: (1) Myometrial response to oxytocin in late pregnant ewes is influenced by the mode of administration; (2) administration of oxytocin to pregnant ewes resulted in a decrease in fetal PO 2 , and thus fetal hypoxemia cannot be attributed exclusively to increased contracture frequency.
Dietary Antibiotics and the Absorption of Zinc-65 and 131I-Labeled Oleic Acid,

Abstract THE addition of antibiotics to the diet has been repeatedly shown to increase growth rates. This area has been extensively reviewed by Branion et al. (1953) who have also discussed, in the same review, several suggestions as to the mechanism responsible for the observed increase in growth rates. Anderson et al. (1952) and Byerly (1964) and many others have suggested that the inclusion of the antibiotics in the ration of growing animals may improve the absorption of the nutrients in that ration. A recent paper by Lotenkov and Podluzknaya (1967) indicates that chlortetracycline at 20 mg./kg. stimulated intestinal absorption of amino acids in chicks. To further investigate the hypothesis that the growth stimulation obtained by feeding antibiotics was due to increased nutrient absorption, the following study was initiated, using a mineral, zinc, and a fatty acid, oleic acid. PROCEDURE In each of the three trials to be reported, day-old broiler . . .
Bundling ecosystem services in the Panama Canal watershed

Land cover change in watersheds affects the supply of a number of ecosystem services, including water supply, the production of timber and nontimber forest products, the provision of habitat for forest species, and climate regulation through carbon sequestration. The Panama Canal watershed is currently being reforested to protect the dry-season flows needed for Canal operations. Whether reforestation of the watershed is desirable depends on its impacts on all services. We develop a spatially explicit model to evaluate the implications of reforestation both for water flows and for other services. We find that reforestation does not necessarily increase water supply, but does increase carbon sequestration and timber production.
UNDERSTANDING THE ACCEPTANCE OF MOBILE SMS ADVERTISING AMONG YOUNG CHINESE CONSUMERS

This study examined the acceptance of SMS advertising, an increasingly popular mobile marketing practice, among young Chinese consumers. A modified technology acceptance model (TAM) was developed to test the intention to use SMS advertising—that is, to read the advertising message and take action as suggested by the message. Data were collected from 262 mobile phone users who were 21–35 years old. The research model was analyzed using structural equation modeling (SEM). Results showed that the two key determinants of TAM, the perceived usefulness and perceived ease of use of SMS advertising messages, predicted the intention to use them. In addition, trust in SMS advertising and subjective norms also contributed to the intention to use. The antecedents and consequents of perceived usefulness and trust were also examined in the SMS advertising context. Overall, the model is well supported. This study represents a novel approach to studying the effectiveness of SMS advertising by applying a model developed in information technology. It also revitalizes the theory of reasoned action in advertising research. The findings have important implications for studying advertising and marketing activities that utilize new media. In addition, practical implications are discussed and directions for future research are suggested. © 2008 Wiley Periodicals, Inc.
Fabrication of aspherics using a mathematical model for material removal.

A mathematical model has been developed that predicts the aspheric surface that a typical optical surfacing machine will produce. The model, which combines two basic assumptions concerning material wear with the kinematics of the machine, has been verified experimentally for the grinding process. In region of the surface where the tool extends beyond the edge of the workpiece, pressure becomes nonuniform, and the model must be altered. The established model has been used to synthesize those machine strokes required to produce a desired aspheric surface.
Global gene expression as a function of the iron status of the bacterial cell: influence of differentially expressed genes in the virulence of the human pathogen Vibrio vulnificus.

Vibrio vulnificus multiplies rapidly in host tissues under iron-overloaded conditions. To understand the effects of iron in the physiology of this pathogen, we performed a genome-wide transcriptional analysis of V. vulnificus growing at three different iron concentrations, i.e., iron-limiting [Trypticase soy broth with 1.5% NaCl (TSBS) plus ethylenediamine-di-(o-hydroxyphenylacetic) acid (EDDA)], low-iron (1 μg Fe/ml; TSBS), and iron-rich (38 μg Fe/ml; TSBS plus ferric ammonium citrate) concentrations. A few genes were upregulated under the last two conditions, while several genes were expressed differentially under only one of them. A gene upregulated under both conditions encodes the outer membrane porin, OmpH, while others are related to the biosynthesis of amino sugars. An ompH mutant showed sensitivity to sodium dodecyl sulfate (SDS) and polymyxin B and also had a reduced competitive index compared with the wild type in the iron-overloaded mice. Under iron-limiting conditions, two of the TonB systems involved in vulnibactin transport were induced. These genes were essential for virulence in the iron-overloaded mice inoculated subcutaneously, underscoring the importance of active iron transport in infection, even under the high-iron conditions of this animal model. Furthermore, we demonstrated that a RyhB homologue is also essential for virulence in the iron-overloaded mouse. This novel information on the role of genes induced under iron limitation in the iron-overloaded mouse model and the finding of new genes with putative roles in virulence that are expressed only under iron-rich conditions shed light on the many strategies used by this pathogen to multiply rapidly in the susceptible host.
Robust control design for an aircraft gust attenuation problem

A method that leads to a minimal-order controller that guarantees robust disturbance rejection for uncertain systems via the solution of simple design equations was presented by H.H. Yeh et al. (1992). In the present work, the authors demonstrate the application of this method to an aircraft gust attenuation problem. The design algorithm presented here was successfully applied to synthesize a minimal-order robust controller for attenuating an aircraft lateral gust. >
Cigarette smoking and other behavioral risk factors related to unintended pregnancy

T1/2was unaffected by OXY (P>0.05) and OXY pharmacodynamics were unaltered by ACZ. OXY PK datawill be shown, aswill ACZ ERs, followed for 1 week after final dose. Conclusions: ACZ AUC and ER show low variability and little interaction with the model medication, consistent with a viable adherence marker. The long beta T1/2 and low ER variation may provide for extended “time since last dose” evaluation. Financial support: R01DA016718-08S1 (SLW), UL1RR033173 (UK CTSA).
Potential novel risk factors for autochthonous and sylvatic transmission of human Chagas disease in the United States

Chagas disease is an emerging vector-borne disease in the United States that causes progressive dilated cardiomyopathy in a third of infected humans. While transmission studies have been performed in Latin America, little is known about the source of infection in locally acquired cases in the United States. This letter describes the underlying factors possibly leading to an increased risk of disease transmission among high-risk groups in the United States.
Cross-layer analysis of error control in underwater wireless sensor networks

Several error control schemes have been introduced for Underwater Wireless Sensor Networks (UWSNs) to combat the effects of high error rates. However, these schemes have only been evaluated based on point-to-point communication metrics and do not consider the different underwater propagation phenomena. On the other hand, the unique properties of UWSNs such as the three-dimensional architecture and the underwater channel characteristics prevent existing studies of error control schemes for terrestrial sensor networks to be applied to this domain. In this paper, a cross-layer analysis framework is developed to evaluate existing error control techniques in three-dimensional multi-hop UWSNs. The developed framework captures the effects of automatic repeat request (ARQ), forward error correction (FEC), and hybrid ARQ schemes on end-to-end energy, latency, and packet error rate. In addition, different underwater propagation phenomena are considered with a particular attention on the presence of shadow zones. The theoretical analysis and the numerical evaluations reveal that exploiting FEC schemes with channel-aware routing reduces the end-to-end energy consumption and latency under all propagation phenomena for all water depths in UWSNs. The selection of the suitable error control scheme depends also on the water depth (shallow/deep water) and on the different underwater propagation phenomena.