cssi/SciSciGPT-SciSciNet huggingface dataset:
On the importance of being ionized.

Abstract A survey of metabolic reactions discloses that all the known lowmolecular weight and water-soluble biosynthetic intermediates possess groups that are essentially completely ionized at neutral pH. In some sequences (e.g., glycolysis, the pentose phosphate pathway, most of the histidine pathway, and purine biosynthesis) the components are all phosphorylated and usually not carboxylated. In many other sequences (e.g., the tricarboxylic acid cycle pyrimidine biosynthesis, most amino acid pathways) the components are carboxylated and usually not phosphorylated. In a few instances (histidinol, spermine) there is an ionizable basic but not an acidic group. Uncharged metabolites are found only as excretory and fermentation products, and occasionally as intermediates in purely degradative reactions (e.g., acetaldehyde in alcoholic fermentation). This generalization should have value in guiding investigation of undisclosed biosynthetic reactions. More important is the problem of determining the principle of cell physiology that lends such evolutionary advantage to ionized biosynthetic intermediates. One possibility is the more efficient retention of ionized compounds within the cell or its organelles.
Modeling the effects of bond environment on equilibrium iron isotope fractionation in ferric aquo-chloro complexes

Four or five sets of ab initio models, including Unrestricted Hartree Fock (UHF) and hybrid Density Functional Theory (DFT) are calculated for each species in a series of aqueous ferric aquo-chloro complexes: Fe(H2O)63+, FeCl(H2O)52+, FeCl2(H2O)4+, FeCl3(H2O)3, FeCl3(H2O)2, FeCl4-, FeCl5H2O2−, FeCl52-, FeCl63-) in order to determine the relative isotopic fractionation among the complexes, to compare the results of different models for the same complexes, to examine factors that influence the magnitude of the isotopic fractionation, and to compare bond-partner-driven fractionation with redox-driven fractionation. Relative to Fe(H2O)63+, all models show a nearly linear decrease in 56Fe/54Fe as the number of Cl− ions per Fe3+ ion increases, with slopes of −0.8‰ to −1.0‰ per Cl− at 20 °C. At 20 °C, 1000 ln β (β = 56Fe/54Fe reduced partition function ratio relative to a dissociated Fe atom) values range from 8.93‰ to 9.73‰ for Fe(H2O)63+, 8.04–9.12‰ for FeCl(H2O)52+, 7.61–8.73‰ for FeCl2(H2O)4+, 7.14–8.25‰ for FeCl4-, and 3.09–4.41‰ for FeCl63-. The fractionation between Fe(H2O)63+ and FeCl4- ranges from 1.5‰ to 2.6‰, depending on the model; this is comparable in magnitude to fractionation effects due to Fe3+/Fe2+ redox reactions. β values from the UHF models are consistently higher than those from the hybrid DFT models. Isotopic fractionation is shown to be sensitive to differences in ligand bond stiffness (above), coordination number, bond length, and the frequency of the asymmetric Fe–X stretching vibrational mode, as predicted by previous theoretical studies. Complexes with smaller coordination numbers have higher 1000 ln β (7.46‰, 5.25‰, and 3.48‰ for FeCl4-, FeCl52-,FeCl63-, respectively, from the B3LYP/6-31G(d) model). Species with the same number of chlorides but fewer waters also show the effect of coordination number on 1000 ln β: (7.46‰ vs. 7.05‰ for FeCl3(H2O)2 vs. FeCl3(H2O)3 and 5.25‰ vs. 4.94‰ for FeCl52- vs. FeCl5H2O2− with the B3LYP/6-31G(d) model). As more Fe–Cl bonds substitute for Fe–OH2 bonds (with a resulting decrease in β), the lengths of the Fe–Cl bonds and the Fe–O bonds increase. Preliminary modeling of Fe(H2O)62+ shows an Fe3+/Fe2+ fractionation of 3.2‰ for the B3LYP/6-31G(d) model, in agreement with previous studies. The addition of an explicit outer hydration sphere of 12 H2O molecules to models of Fe(H2O)63+ improves agreement with measured vibrational frequencies and bond lengths; 1000 ln β increases by 0.8–1.0‰. An additional hydration sphere around FeCl4- increases 1000 ln β by only 0.1‰. Isotopic fractionations predicted for this simple system imply that ligands present in an aqueous iron environment are potentially important drivers of fractionation, and suggest that significant fractionation effects are likely in other aqueous systems containing sulfides or organic ligands. Fractionation effects due to both speciation and redox must be considered when interpreting iron isotope fractionations in the geological record.
Do ranks suffice? A comparison of alternative weighting approaches in value elicitation

Abstract We compared both attribute weights and overall evaluations for students′ preferences among apartments described to them in terms of nine independent attributes. Methods used for eliciting attribute weights were (a) 7-point scales; (b) value hierarchy; (c) swing weights; and two methods using importance rankings only: (d) rank order centroid and (e) rank sum weights. Multiple linear regression was also used to infer attribute weights. Test–retest reliability of overall evaluations was found to be modest. Evaluation models based on all five weight elicitation methods were superior to an equal weights model, with rank order centroid weights modestly superior to other methods.
Aging in large CDF tracking chambers

Abstract The experience of the Collider Detector at Fermilab (CDF) with aging in the large axial drift chamber responsible for tracking in the central region is presented. Premature aging in the Run 1 chamber was observed after only 0.02 C/cm. After cleaning much of the gas system and making modifications to reduce aerosols from the alcohol bubbler, the observed aging rate fell dramatically in test chambers. Considerable effort has been made to better understand the factors that affect aging since the replacement chamber for Run 2 will accumulate about 1.0 C/cm. Current test chambers using the full CDF gas system show aging rates of less than 5%/C/cm.
Glandular cell atypia on Papanicolaou smears: interobserver variability in the diagnosis and prediction of cell of origin.

BACKGROUND The 2001 Bethesda System recommended qualification of atypical glandular cells (AGC) to indicate the site of origin and separated endocervical adenocarcinoma in situ (AIS) from “AGC favor neoplastic” as a specific diagnostic category. To the authors' knowledge, the literature evaluating the reproducibility of Papanicolaou (Pap) smear diagnosis of glandular cell abnormalities with emphasis on the cell of origin is limited. The aim of the current study was to investigate whether a variety of benign to neoplastic glandular lesions can be reliably classified on Pap smear with regard to diagnosis and cell of origin. METHODS Twenty-three conventional Pap smears (CPS) with glandular cellular changes varying from benign to adenocarcinoma (ACA) were reviewed by six observers. They were asked to categorize each smear according to cell of origin (endocervical vs. endometrial) and diagnosis (benign, AGC, or ACA). Kappa statistics were used to evaluate interobserver agreement and correlation of interobserver agreement with experience. RESULTS There was no consensus among observers for both the origin of the cells and the diagnosis. Interobserver agreement for site was poor (kappa < 0.4) especially in the AGC category. Unanimous agreement for site was reached for 7 of 23 smears (30%). Two of five endocervical AIS were classified as endometrial and another two were classified as benign by four observers. Interobserver agreement was poor in all diagnostic categories (kappa < 0.4) and showed slight correlation with level of experience. Unanimous agreement for diagnosis was reached for only 2 smears (9%). Three of 11 (27%) smears demonstrating preneoplastic/neoplastic processes were diagnosed as benign by 3 observers. Three (25%) benign CPS were diagnosed as ACA by 2 observers. Accurate prediction of the final histologic diagnosis by observers varied from 30% to 87% and did not correlate closely with experience. CONCLUSIONS Cytologic diagnosis of glandular lesions by CPS was problematic and suffered from significant interobserver subjectivity. Cancer (Cancer Cytopathol) 2003;99;323–30. © 2003 American Cancer Society.
A phase II trial of tricyclic nucleoside phosphate in patients with advanced squamous cell carcinoma of the cervix. A Gynecologic Oncology Group Study.

A Phase II trial of TCN-P was conducted in metastatic or recurrent squamous cell carcinoma of the cervix using a 5-day continuous infusion schedule. The starting dose was 35 mg/m2 × 5 days and courses were repeated every 6 weeks. Among 21 evaluable patients, 2 responses were observed. One patient had a complete response for 19+ months. Another patient had a partial response for 5+ months, but developed symptomatic hypocalcemia, requiring discontinuation of the drug. Using this dose and schedule TCN-P appears to have limited activity in metastatic or recurrent squamous cell cancer of the cervix.
Microbial-generated amyloids and Alzheimer's disease (AD).

Atypical amyloid generation, folding, aggregation and impaired clearance are characteristic pathological features of human neurodegenerative disorders including Alzheimer's disease (AD). What is generally not appreciated is that a major secretory product of microbes is amyloid, and that the contribution of microbial amyloid to the pathophysiology of the human central nervous system (CNS) is potentially substantial. While earlier findings suggested that these amyloids may serve some immune-evasive strategy, it has recently become evident that humans have a tremendously heavy systemic burden of amyloid which may contribute to the pathology of progressive neurological diseases with an amyloidogenic component. This perspective will highlight some recent inroads made into our understanding of the enigmatic role that microbial amyloids may play in the homeostasis and pathology of the CNS with particular reference to AD wherever possible.
HIGH BREVETOXIN CONCENTRATIONS IN GYMNODINIUM BREVE BLOOMS ALONG THE NORTHWEST FLORIDA COAST DURING 1999

Blooms of the dinoflagellate Gymnodinium breve (i.e. red tides) produce brevetoxins (PbTx) that negatively impact the Gulf of Mexico ecosystem, human health, and local economies. Characterizing and predicting bloom events and their impacts requires knowledge of G. breve abundance and PbTx concentrations in the water column. We report results from a bloom that occurred during the fall and winter of 1999 in NW Florida coastal waters. Data were collected from 16 stations on 3 sampling dates (29 Sept., 9 Nov., 1 Dec.), including basic hydrography, nutrient concentrations, G. breve abundances, and brevetoxin concentrations. G. breve cells were enumerated using flow cytometry and PbTx's were isolated from seawater using dichloromethane (DCM) partitioning. Brevetoxins were quantified by HPLC-DAD using a C-18 column and an acetonitrile-water gradient elution. Literature estimates of total PbTx concentration (PbTx's 1, 2, 3) of cultured and field-collected G. breve suggest a range in concentration from 7 to 17 pg cell−1. We measured total PbTx levels that greatly exceeded these values [Sept., 47–67 pg cell−1 (n=5); Nov., 59–126 pg cell−1 (n=3), Dec., 12–63 pg cell−1 (n=8)]. PbTx-2 was the predominant (67–75%) PbTx isomer found in these blooms. PbTx-1 and PbTx-3 were found at 11–22% and ND–28% of total PbTx, respectively.
On the consistency of the objective Bayes factor for the integral priors in the one-way random effects model

Abstract The Bayes factor for the integral priors in the one-way random effects model has recently been developed by Cano et al. (2007). We establish the consistency of this Bayes factor when the number of groups goes to infinity, when the number of observations per group goes to infinity, and when both go to infinity.
Effect of nonprecipitating clouds on the aerosol size distribution in the marine boundary layer

The size distribution of particles smaller than 0.5 µm has been measured over the tropical Atlantic and Pacific oceans with a differential mobility analyzer. In regions remote from continental influences the size distribution generally has peaks at about .02-.03 µm and at .08-.15 µm with a minimum in the .05-.08 µm radius range. The data provides strong evidence that nonprecipitating clouds play an important role in transferring material from the gas phase and from smaller particles into the 0.08 to .15 µm radius range, and that they are responsible for the doubly peaked size distributions frequently observed over the oceans.
Potentially dangerous patients: a review of the duty to warn.

I want to bring an error in a recent article to your attention. I was reading the article Potentially Dangerous Patients: A Review of the Duty to Warn by Elizabeth Henderson, and a major error jumped out at me. The article states that Texas recognizes “...Tarasoff as a legitimate piece of legislation, allowing but not mandating named professionals to warn potential victims.” This statement is completely false. Some of the other states mentioned are not exactly as portrayed either, but I ammost familiar with Texas because I am a licensed psychologist here and teach the doctoral classes in ethics at Southern Methodist University. In Thapar v Zezulka (1999), the Supreme Court of Texas found that there is no duty to warn and that mental health professionals cannot warn a potential victim. The Texas Supreme Court found that mental health professionals may contact the police or other health experts in cases of dangerousness but that our statutes (611.004) are permissive, not required reporting, and as such, it is possible that a civil case could be brought against a health practitioner for breaking confidentiality even when reportidentified specific professional groups as having an obligation to warn others. According the National Conference of State Legislatures, New Mexico does have a law regarding the duty to warn, but the specifics of this law are unclear. Finally, Oklahoma’s Title 59 § 1376, enacted in 2004, requires reporting of imminent threat but is more restrictive when permitted to breach patient confidentiality. Because of the legal implications and potential for physical harm to individuals that may result from using erroneous and/ or out-of-date information, having correct data regarding duty to warn is paramount.—Deanna Settelmeyer, MSN, RN, CEN, Doctor of Nursing Practice Candidate, University of Virginia, North Garden, VA; E-mail: drs5eq@virginia.edu
Abstract C48: Regulation of expression of CXCL12 and its receptors CXCR4 and CXCR7 by PTEN in prostate cancer

Abstract Introduction: Expression of the chemokine CXCL12, also known as SDF-1, and its receptors, CXCR4 and CXCR7, are associated with prostate cancer (PC) metastasis. Loss of the tumor suppressor PTEN (phosphatase and tensin homolog) occurs in 30-80% of primary PCs, and up to 50% of PC bone metastases. In mouse models, prostate-specific deletion of PTEN leads to Akt activation and increased expression of CXCR4 and CXCL12. Moreover, the level of PTEN expression is inversely associated with prostate tumorigenesis. Additionally, HIF-1α, a hypoxia-induced transcription factor previously shown to induce expression of CXCR4, is regulated by Akt. Thus, we hypothesize that the PTEN loss-mediated activation of HIF-1α regulates the function of CXCR4 and CXCR7 receptor pathways in PC progression. Methods: Prostate-specific deletion of floxed exon 5 of PTEN was achieved by Cre recombinase expressed under the control of an androgen-responsive probasin promoter. Stable cell lines developed from PTEN+/+, PTEN+/−, and PTEN−/− murine prostate epithelial cells that were isolated from the prostates of corresponding mice at 8 weeks of age, and the PTEN status in these cell lines was confirmed by genotyping and immunoblot analyses. Subsequently, these cells were treated with inhibitors of the PI3K/Akt pathway, and gene expression was determined by real time PCR. Results: We found that loss of PTEN resulted in increased expression of CXCR4, CXCR7, and CXCL12, suggesting that loss of PTEN may play a key role in the regulation of these chemokines in prostate cancer. Additionally, expression of HIF-1α was also upregulated upon PTEN loss. Upon treatment of PTEN−/− cells with inhibitors of the PI3K/Akt pathway, the induction of CXCL12 and CXCR7 was reversed, further demonstrating the role of the PTEN regulated pathway in the expression of these genes. Conclusions: These results suggest a molecular basis for activation of CXCL12 signaling through its receptors in prostate cancer driven by the loss of PTEN through the induction of HIF-1. Citation Format: M. Katie Conley-LaComb, Yong Q. Chen, Hyeong-Reh C. Kim, Michael L. Cher, Sreenivasa R. Chinni. Regulation of expression of CXCL12 and its receptors CXCR4 and CXCR7 by PTEN in prostate cancer [abstract]. In: Proceedings of the AACR Special Conference on Advances in Prostate Cancer Research; 2012 Feb 6-9; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2012;72(4 Suppl):Abstract nr C48.
Motion artifact reduction with predictive gating

It is well known that patient motion causes artifacts that can mimic disease and lead to mis-diagnosis. Various physiological gating methods have been investigated in the past to combat this problem by acquiring CT scans during the quiescent motion periods. Previously, we proposed a predictive gating algorithm for computing the quiescent time intervals to automatically starting the scanner. The algorithm uses adaptive moving correlation to exploit the fact that the shape of the inspiratory or expiratory segment of the waveform is similar from breath to breath. The CT data acquisition is triggered when the correlation coefficient exceeds a predefined threshold. Although this method performs satisfactorily in most patients, it fails to trigger CT scans in some patients when excessive variation in the motion waveform exists. To overcome this difficulty, we propose an improved algorithm that will determine the correlation threshold based on the waveform history acquired during the patient preparation. We further exclude the portions of the breathing curve that deviate significantly from the average breathing curve based on the low correlation coefficients. We then calculate the weighted correlation coefficients with the most recent samples carrying higher weights. The start of a CT scan is then determined based on the weighted average. Various experiments have demonstrated the advantages and effectiveness of our approach.© (1996) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Derivative evaluation and computational experience with large bilevel mathematical programs

A bilevel program is a mathematical program involving functions defined implicitly as solutions to another mathematical program. We discuss a method for extracting derivative information on the implicit function, which is especially efficient when the lower-level problem has simple bounds on the variables and/or many inactive constraints. Computational experience on problems with up to 230 variables and 30 constraints is presented.
Revision of a multiparameter equation of state to improve the representation in the critical region : application to water

Abstract We have developed a crossover formalism for the thermodynamic surface of pure fluids, which can be applied to any multiparameter equation of state. This procedure has been used to incorporate scaling law behavior into a representation of the thermodynamic properties of water and steam developed by Pruss and Wagner (PW EOS) and adopted recently by the International Association for the Properties of Water and Steam. Our revision to this equation retains most of the functional form and coefficients of the PW EOS, but replaces two of the terms with a crossover representation of scaling law behavior. In order to develop this model, we first developed a new crossover formulation for steam in the critical region, and second, we have incorporated universal crossover functions into the original PW EOS. In the modified form, the PW equation of state reproduces the scaling laws down to dimensionless temperatures τ =10 −7 . Far from the critical point the equations practically coincide.
Atrial pacing for the prevention of atrial fibrillation after cardiovascular surgery.

Abstract OBJECTIVE The purpose of this study was to determine the efficacy of atrial pacing in the prevention of atrial fibrillation following cardiovascular surgery. BACKGROUND Although pharmacologic therapy has been used to help prevent postoperative atrial fibrillation, it suffers from limited efficacy and adverse effects. In the nonoperative setting, novel pacing strategies have been shown to reduce recurrences of atrial fibrillation and prolong arrhythmia-free periods in patients with paroxysmal atrial arrhythmias. METHODS A total of 154 patients (115 men; mean age, 65 ± 10 years; ejection fraction, 53 ± 10%) undergoing cardiac surgery (coronary artery bypass surgery, 88.3%; aortic valve replacement, 4.5%; coronary bypass + aortic valve replacement, 7.1%) had right and left atrial epicardial pacing electrodes placed at the time of surgery. Patients were randomized to either no pacing, right atrial (RAP), left atrial (LAP) or biatrial pacing (BAP) for 72 h after surgery. Beta-adrenergic blocking agents were administered concurrently to all patients following surgery. RESULTS There was a reduction in the incidence of postoperative atrial fibrillation from 37.5% in patients receiving no postoperative pacing to 17% (p CONCLUSION Postoperative atrial pacing, in conjunction with beta-blockade, significantly reduced both the incidence of atrial fibrillation and the length of hospital stay following cardiovascular surgery. Additional studies are needed to determine the most effective anatomic pacing site.
High aspect ratio plasma etching of bulk lead zirconate titanate

Lead Zirconate Titanate (PZT) is a high energy density active material with good piezoelectric coefficient and electromechanical coupling constant making it highly suitable for microsystems applications. In this paper, we present a rapid anisotropic high aspect ratio etching process for defining micron size features in PZT. We used an inductively coupled plasma reactive ion etching (ICP-RIE) system employing sulfur hexafluoride (SF6) and argon (Ar) based chemistry. A seed layer of Au/Cr was lithographically patterned onto fine lap finished PZT-4 substrates followed by electrodeposition of a thick 2-5 μm nickel on the seed layer, which acts as a hard mask during the etching process. The demonstrated technique was used to etch bulk PZT ceramic substrates, thereby opening possibilities for integration of bulk PZT substrates and structures into microsystems. A maximum etch rate of 19 μm/hr on PZT-4 and 25 μm/hr for PZT-5A compositions was obtained using 2000 W of ICP power, 475 W of substrate power, 5 sccm of SF 6 , and 50 sccm of Ar on PZT substrate. We have also demonstrated a high aspect ratio etch (>5:1) on a 3 μm feature size. Detailed analysis of the effects of ICP power, substrate power, and the etch gas composition on the etch rate of PZT are also presented in this article.
Quantification of crystalline cellulose in lignocellulosic biomass using sum frequency generation (SFG) vibration spectroscopy and comparison with other analytical methods

The non-centrosymmetry requirement of sum frequency generation (SFG) vibration spectroscopy allows the detection and quantification of crystalline cellulose in lignocellulose biomass without spectral interferences from hemicelluloses and lignin. This paper shows a correlation between the amount of crystalline cellulose in biomass and the SFG signal intensity. Model biomass samples were prepared by mixing commercially available cellulose, xylan, and lignin to defined concentrations. The SFG signal intensity was found sensitive to a wide range of crystallinity, but varied non-linearly with the mass fraction of cellulose in the samples. This might be due to the matrix effects such as light scattering and absorption by xylan and lignin, as well as the non-linear density dependence of the SFG process itself. Comparison with other techniques such as XRD, FT-Raman, FT-IR and NMR demonstrate that SFG can be a complementary and sensitive tool to assess crystalline cellulose in biomass.
Overexpression of connexin43 alters the mutant phenotype of midgestational wnt-1 null mice resulting in recovery of the midbrain and cerebellum.

The midbrain-hindbrain (MHB) junction plays a key role in the patterning of the embryonic neural tube and the formation of brain structures such as the cerebellum. The mitogen wnt-1 is critical for cerebellar development, as evidenced by the lack of MHB region and cerebellar formation in the wnt-1 null embryo. We have generated wnt-1 null embryos overexpressing the gap junction gene connexin43 by crossing wnt-1 null heterozygotes into the CMV43 mouse line. We have confirmed that these mice show an increase in gap junctional communication by dye coupling analysis. Two-thirds of wnt-1 null CMV43+ mouse embryos at E18.5 have a cerebellum. In addition, changes in the wnt-1 null phenotype in mouse embryos overexpressing connexin43 are observed as early as E9.5. At this stage, one-quarter of wnt-1 null CMV43+ embryos display extra or expanded tissue present at the MHB boundary (a wnt-1 null enlarged phenotype). In situ hybridization studies conducted on these embryos have indicated no changes in the expression of embryonic brain positional markers in this region. We conclude from these studies that overexpression of the connexin43 gap junction restores cerebellar formation by compensating for the loss of wnt-1. © 2005 Wiley-Liss, Inc.
Oxidation of a zirconia-toughened

A Ni3Al composite reinforced with zirconia-toughened alumina fiber, PRD-166 fiber, was produced by pressure casting. The thermochemical stability of the composite at 1100 °C in vacuum and air was investigated by optical and transmission electron microscopy and energy- dispersive spectroscopy (EDS). Vacuum annealing resulted in precipitation of needle-shaped ZrB and cuboid-shaped Cr-rich, tentatively identified as Cr7C3, particles. Annealing in air led to the precipitation of large ZrO2 particles at the fiber/matrix interface and fine ZrO2 platelets in the matrix. A thin layer of A12O3 was observed to cover the fiber/matrix interface and to envelop the ZrO2 platelets. Diffusion of Ni through the A12O3 layer and its oxidation and sub- sequent reaction with A12O3 resulted in the formation of NiAl2O4 spinel around the ZrO2 particles at the fiber/matrix interface. Further annealing resulted in the formation of a thin layer of Cr2O3 on the A12O3 layer and precipitation of A12O3 and Cr2O3 particles within the matrix. These particles subsequently reacted with NiO to form Ni(AlxCr1-x)2O4grains. Diffusion of oxygen through the fiber is believed to be responsible for the rapid oxidation of the composite.
The pathways for thermal decomposition of aryl alkyl ethers during coal pyrolysis

Abstract Wyodak subbituminous coal was reacted with methyl- 13 C iodide under basic conditions to obtain modified labelled coal. The modified coal was pyrolysed in a wire screen reactor at 700–800 °C. The distribution of the label among the gaseous products was established by g.c.-m.s.. Of all the labelled ethers that undergo thermal decomposition to form gaseous products, the 13 C product distribution is as follows. Approximately 78% of the label appeared in methane, 14% in carbon monoxide, 4.5% in methanol, 1.5% in carbon dioxide and 2% in ethane. These results are examined on the basis of the reaction pathways available for the decomposition of the aryl methyl ethers in coal. The observations are compatible with the view that simple carbon-oxygen bond scisson is the dominant reaction, but they also indicate that the decomposition reactions initiated by hydrogen atom abstraction from the methyl groups play a role in the formation of carbon monoxide. The results for Wyodak coal and for Illinois No. 6 coal are also consistent with the idea that certain hindered aryl methyl ethers undergo decomposition selectively. An explanation for this finding is advanced.
Single-particle and collective excitations in a solvable many-fermion system☆

Abstract A model Hamiltonian with a two-body interaction that is attractive in the 1S0 and 3P0 partial waves is shown to be exactly solvable for any number of fermions when the two partial waves have equal interaction strengths. It is shown that the ground state has the structure of a condensate of bound four-fermion subsystems. The excitation spectrum is shown to have two branches — a single-particle branch of the type usually found in superconductivity theory and collective branch in which the excitation energies are of the order of 1 n , where n is the number of particles. The independent quasiparticle approximation plus use of the cranking model is shown to give the exact excitation spectrum of the collective states under certain circumstances.
Adaptive forgetting in animals

An argument is presented for the possibility that some cases of forgetting in animals are adaptive. In contrast to research on human memory, the idea of adaptive forgetting has not received much attention in research with animals. This paper reviews the status of adaptive forgetting in humans and then outlines an argument for adaptive forgetting in animals. The discussion includes theoretical presuppositions concerning forgetting, a review of selective phenomena indicative of adaptive forgetting in animals, a description of a possible mechanism (retrievability) for this kind of forgetting, and examination of the implications of this analysis for psychological and neurobiological approaches to memory processing.
Guidance characteristics of GNSS landing systems

Technical and operation concepts for precision landing have evolved around the signal in space characteristics of the Instrument Landing System (ILS). For the Global Navigation Satellite System (GNSS) Landing System (GLS), many of these characteristics will be dependent on computational processes inside the airborne receiver. Development of GLS standards creates an opportunity to improve on inherent ILS limitations while retaining useful features. This paper compares proposed GLS guidance algorithms including an approach where nominal ILS features are reproduced as well as alternatives proposed to eliminate features seen as undesirable. Simulated deviation outputs are derived for various maneuvers, including orbits, on-path, and near-path approach trajectories. The potential impact of alternative approaches on aircraft performance during capture, flare, and rollout is shown. Additional considerations addressed include the impact of changes of field verification and flight inspection and the applicability of these concepts to the Multi-Mode Receiver (MMR).
Isogeometric Analysis of Structural Vibrations

This paper begins with personal recollections of John H. Argyris. The geometrical spirit embodied in Argyris’s work is revived in the sequel in applying the newly developed concept of isogeometric analysis to structural vibration problems. After reviewing some fundamentals of isogeometric analysis, application is made to several structural models, including rods, thin beams, membranes, and thin plates. Rotationless beam and plate models are utilized as well as three-dimensional solid models. The concept of k-refinement is explored and shown to produce more accurate and robust results than corresponding finite elements. Through the use of nonlinear parameterization, “optical” branches of frequency spectra are eliminated for k-refined meshes. Optical branches have been identified as contributors to Gibbs phenomena in wave propagation problems and the cause of rapid degradation of higher modes in p-method finite elements. A geometrically exact model of the NASA Aluminum Testbed Cylinder is constructed and frequencies and mode shapes are computed and shown to compare favorably with experimental results.
Inhibition of the development of metastatic squamous cell carcinoma in protein kinase C epsilon transgenic mice by alpha-difluoromethylornithine accompanied by marked hair follicle degeneration and hair loss.

The role of 12- O -tetradecanoylphorbol-13-acetate (TPA)-stimulated polyamine biosynthesis in the development of metastatic squamous cell carcinoma (mSCC) in protein kinase C e (PKCe) transgenic mice was determined. TPA treatment induced epidermal ornithine decarboxylase (ODC) activity and putrescine levels approximately 3–4-fold more in PKCe transgenic mice than their wild-type littermates. Development of mSCC by the 7,12-dimethylbenz( a )anthracene (100 nmol)-TPA (5 nmol) protocol in PKCe transgenic mice was completely prevented by administration of the suicide inhibitor of ODC α-difluoromethylornithine (DFMO, 0.5% w/v) in the drinking water during TPA promotion. However, DFMO treatment led to marked hair loss in PKCe transgenic mice. DFMO treatment-associated hair loss in PKCe transgenic mice was accompanied by a decrease in the number of intact hair follicles. These results indicate that TPA-induced ODC activity and the resultant accumulation of putrescine in PKCe transgenic mice are linked to growth and maintenance of hair follicles, and the development of mSCC. Severe hair loss observed in PKCe transgenic mice on DFMO during skin tumor promotion has not been reported before in the prevention of cancer in other animal models or in human cancer prevention trials.
An Investigation of Epistemological and Social Dimensions of Teaching in Online Learning Environments

We examine the relationship between teaching approaches and online learning outcomes using a sample of 40 MBA-level courses. We develop and test a conceptual framework of teaching approaches based ...
Sox9 transactivation and testicular expression of a novel human gene, KIAA0800.

The Sry and Sox9 sex-determination factors initiate and promote testis differentiation by gene transactivation through similar promoter elements. However, knowledge is limited concerning what genes are regulated by Sry/Sox9 in the testis. Identification and characterization of Sry/Sox9-regulated genes are critical for understanding sexual differentiation. We now demonstrate that a novel human gene, KIAA0800, is preferentially expressed in the testis and is transactivated by Sox9. The KIAA0800 promoter is repressed by an upstream element involving a polyT track and two Alu repeats. Two specific Sox9-bindings sites have been identified in the KIAA0800 promoter by using DNaseI footprinting assays and gel electrophoretic mobility shift assays. Sox9 transactivation of the KIAA0800 promoter appears to be exerted mainly through the relief of promoter repression. Genes homologous to the human KIAA0800 exist in organisms with differentiated sex tissues including mouse, Drosophila, and C. elegans, but not in unicellular organisms, including yeast and bacteria. Further, our recent sequence analysis shows that KIAA0800 protein is 97% identical between human and mouse. Thus, KIAA0800 is a novel Sox9-activated gene that is evolutionarily conserved and potentially involved in sexual differentiation. J. Cell. Biochem. 86: 277–289, 2002. © 2002 Wiley-Liss, Inc.
Dithiocarbamate-Capped Silver Nanoparticles

Nanometer-sized silver particles were synthesized by using didecylamine dithiocarbamates as the protecting ligands. With control of the initial ligand−metal feed ratios, the core diameter of the resulting particles was found to vary from about 5 to 2.5 nm, as determined by transmission electron microscopic measurements. The core size dispersity was also found to decrease with increasing feed ratio. In UV−visible spectroscopic studies, the particle surface plasmon resonance peak diminished in intensity as the particle core size decreased, whereas in electrochemical measurements, smaller sized particles gave rise to well-defined quantized charging voltammetric features, in contrast to the featureless responses with the larger particles. Such single electron-transfer behaviors were consistent with those observed in STM measurements involving individual nanoparticles. Overall, this study provides an effective approach to the synthesis of stable nanometer-sized silver nanoparticles with interesting electronic ...
iPlane Nano: path prediction for peer-to-peer applications

Many peer-to-peer distributed applications can benefit from accurate predictions of Internet path performance. Existing approaches either 1) achieve high accuracy for sophisticated path properties, but adopt an unscalable centralized approach, or 2) are lightweight and decentralized, but work only for latency prediction. In this paper, we present the design and implementation of iPlane Nano, a library for delivering Internet path information to peer-to-peer applications. iPlane Nano is itself a peer-to-peer application, and scales to a large number of end hosts with little centralized infrastructure and with a low cost of participation. The key enabling idea underlying iPlane Nano is a compact model of Internet routing. Our model can accurately predict end-to-end PoP-level paths, latencies, and loss rates between arbitrary hosts on the Internet, with 70% of AS paths predicted exactly in our evaluation set. Yet our model can be stored in less than 7MB and updated with approximately 1MB/day. Our evaluation of iPlane Nano shows that it can provide significant performance improvements for large-scale applications. For example, iPlane Nano yields near-optimal download performance for both small and large files in a P2P content delivery system.
The theory of planned behavior and Internet purchasing

Several opinion polls have found that many consumers resist making purchases via the Internet because of their concerns about the privacy of the personal information they provide to Internet merchants. Using the theory of planned behavior as its basis, this study investigated the relationships among beliefs about Internet privacy and trustworthiness, along with beliefs about perceived behavioral control and the expectations of important others, and online purchasing behavior. Data were collected from 193 college students. Analysis of the data indicates that beliefs about trustworthiness positively affect attitudes toward buying online, which in turn positively affect purchasing behavior. Beliefs about self‐efficacy regarding purchasing positively affect perceived behavioral control, which in turn affects online purchasing behavior. In short, respondents who believed in the trustworthiness of the Internet and in their own abilities to buy online were more likely to make Internet purchases than were those without such beliefs.
The Mass-Action-Law Based GPS Concept for Bio-Informatics

The unified theory of dose and effect, as indicated by the median-effect equation for single and multiple entities and for the first and higher order kinetic/dynamic, has been established by T.C. Chou and it is based on the physical/chemical principle of the mass-action law (_J. Theor. Biol._ 59: 253-276, 1976; _Pharmacological Rev._ 58: 621-681, 2006). Rearrangements of the median-effect equation lead to Michaelis-Menten, Hill, Scatchard, and Henderson-Hasselbalch equations. The “median” serves as the “universal reference point” and the “common link” for the relationship of all entities at all dynamic orders, and is also the “harmonic mean” of kinetic dissociation constants. Over 300 mechanism-specific equations have been derived and published using the mathematical induction-deduction process. These equations can be deduced into several general equations, including the median-mediated whole/part equation, combination index theorem, isobologram equation, and polygonogram. It is proven that “dose” and “effect” are interchangeable, thus, “substance” and “function” are interchangeable, which leads to “the-unity theory” in philosophical context. Based on the mass-action law, the fundamental conceptual claim is that “one can draw a specific cure for only two data points”, if they are determined accurately. Furthermore, instead of drawing an empirical curve for data-fitting, we can now use the data points to fit the median-effect principle of the mass-action law by automated computer simulation. This small kill has far reaching consequences in biomedical sciences including small size experimentation, efficient experimental design and data interpretation, efficiency in drug discoveries, quantifying/simulating synergism in drug combinations, assessing low-dose risk of carcinogens, toxic substances or radiation, and conserving laboratory animals’ lives. For the “combination index” alone, the theory has been cited in over 345 different biomedical journals, based on the Thompson-ISI Web search, indicating broad applications.
Multiple affinity states of cGMP-specific phosphodiesterase for sildenafil inhibition defined by cGMP-dependent and cGMP-independent mechanisms.

cGMP-specific phosphodiesterase (PDE5) has become a target for drug development for the treatment of a number of physiological dysfunctions, affected by changes in the cGMP/cGMP-dependent protein kinase (PKG) signaling pathway. PDE5 has two highly homologous regulatory domains, GAF-A and GAF-B. We showed previously that PDE5 could be converted from a low-activity (nonactivated) state to a high-activity state upon cGMP binding to the GAF-A domain with higher sensitivities toward sildenafil (EMBO J22:469–478, 2003). Here we investigated whether sildenafil sensitivity of PDE5 could be modified by cGMP-independent mechanisms. Individually expressed recombinant GAF-A and GAF-B proteins were tested for their ability to modulate full-length recombinant PDE5 affinity to sildenafil. The GAF-A domain protein had the most dramatic effect on the affinity of the nonactivated recombinant PDE5 for sildenafil, revealing much higher sensitivity to sildenafil inhibition. The apparent affinity for sildenafil increased from the nanomolar range to the picomolar range, providing evidence for the presence of a “super-high” sensitivity state of PDE5 for sildenafil inhibition. In human platelet, higher sensitivity of PDE5 for sildenafil inhibition has been detected after blocking cGMP-binding sites of the GAF-A domain. Thus, our data demonstrate that high sensitivity of PDE5 for sildenafil can be obtained not only through cGMP-induced activation of PDE, but also through cGMP-independent modulation of PDE5 in the nonactivated state, possibly through protein-protein interaction. Furthermore, data suggest that nonactivated PDE5 with “super-high” affinities for sildenafil inhibition may be responsible for therapeutic effects of long-term treatments with low doses of PDE5 inhibitors.
Learning to spell and punctuate: A study of eight‐ and nine‐year‐old children

Abstract. This study explored various aspects of the spelling and punctuation development of six Native American children from the United States during their third and fourth grade years, as seen in classroom writing samples. A number of conclusions were drawn up from the analysis. The subjects spelled most words conventionally. The more frequently a word appeared in the subject's writing, the more likely it was to be spelled conventionally. Selected orthographic features varied widely in how conventionally they were spelled, with those which were less frequent, less predictable, or more abstract tending to be more difficult. Almost every spelling feature examined showed growth from third to fourth grade. The invented spellings of particular features tended to reflect understandable, logical processes. Invented spellings which were either real words or permutations of the intended word were common. Punctuation was more difficult than spelling for the subjects. Children used a variety of linguistic informa...
Design issues when using commodity gaming devices for virtual object manipulation

3D interaction has made a big splash in the gaming community with the Nintendo Wii, Sony Move and Microsoft Kinect; however, most of the interaction is based on natural imprecise motions. By using the wealth of 3D interaction research, we can use these low cost commercial systems to bring not only richer interaction to gaming but also commodity trackers to Virtual Reality research. One of the first steps in understanding how these devices can be used is to determine their limitations and strengths compared to traditional 3D tracking systems.Based on this motivation we chose to implement three well-known interaction techniques---ray casting, HOMER and World-In-Miniature---using the Kinect, Move and Intersense IS-900 (a high-end 3D tracking system). We outline the design challenges of developing for each system. Based on these design issues, we expect to see users having similar results when using the Move and IS-900 systems while having a slight decrease in performance using the Kinect. If our assertions are correct, we will look at how we can design new interactions with these systems that allow for precise and accurate selection and manipulation.
Liking and wanting of drug and non-drug rewards in active cocaine users: the STRAP-R questionnaire:

Few studies have examined the subjective value attributed to drug rewards specifically as it compares with the value attributed to primary non-drug rewards in addicted individuals. The objective of this study is to assess ‘liking’ and ‘wanting’ of expected ‘drug’ rewards as compared to ‘food’ and ‘sex’ while respondents report about three different situations (‘current’, and hypothetical ‘in general’, and ‘under drug influence’). In all, 20 cocaine-addicted individuals (mean abstinence = 2 days) and 20 healthy control subjects were administered the STRAP-R (Sensitivity To Reinforcement of Addictive and other Primary Rewards) questionnaire after receiving an oral dose of the dopamine agonist methylphenidate (20 mg) or placebo. The reinforcers’ relative value changed within the addicted sample when reporting about the ‘under drug influence’ situation (drug > food; otherwise, drug < food). This change was highest in the addicted individuals with the youngest age of cocaine use onset. Moreover, ‘drug’ ‘wantin...
Drought legacies influence the long-term carbon balance of a freshwater marsh

Experimental manipulations provide a powerful tool for understanding an ecosystem's response to environmental perturbation. We combined paired eddy covariance towers with an experimental manipulation of water availability to determine the response of marsh carbon balance to drought. We monitored the Net Ecosystem Exchange of CO2 (NEE) in two ponds from 2004 to 2009 at the San Joaquin Freshwater Marsh (SJFM), and subjected one of the ponds to a yearlong drought treatment in 2007. The two ponds experienced similar flooding and environmental regimes before and after the drought, ensuring that differences between ponds were largely attributable to the 2007 drought. Drought substantially reduced surface greenness, as measured by the Enhanced Vegetation Index (EVI) and photosynthetic carbon sequestration, primarily by inhibiting leaf area development. Respiratory carbon losses were less influenced by drought than photosynthetic carbon gains. The effect of the drought lasted several years, with delayed leaf area development and peak carbon uptake rates during the subsequent year, and reduced leaf area for a couple of years. The combined effect of the drought and legacy effects created an overall loss of carbon that was equivalent to 4 years of the maximum annual carbon sequestration observed over a decade. Our results indicate that drought can have long-term impacts on ecosystem carbon balance and that future projected drought increases in Southern California will have a negative impact on marsh carbon sequestration.
Multigrid acceleration of the flux split Euler equations

Multigrid acceleration is applied to a flux-split algorithm for solving the Euler equations in three dimensions. The basic algorithm is an implicit spatially split approximate factorization method. The stability and performance of the scheme in comparison to other factorizations are examined. Results are presented for three-dimensional flows that demonstrate substantially unproved convergence with the multigrid algorithm.