cssi/SciSciGPT-SciSciNet huggingface dataset:
Influence of ceria and nickel addition to alumina-supported Rh catalyst for propane steam reforming at low temperatures

Abstract The influence of ceria and nickel addition to alumina-supported Rh catalyst for steam reforming of propane at low temperatures has been studied by preparing and examining 2 wt%Rh/Al 2 O 3 , 2 wt%Rh/20 wt%CeO 2 –Al 2 O 3 , and 2 wt%Rh–5 wt%Ni/20 wt%CeO 2 –Al 2 O 3 . TPR characterization showed that adding ceria makes rhodium oxide easier to reduce and the presence of rhodium also makes ceria easier to reduce through Rh–Ce interaction, whereas the addition of Ni makes Rh 2 O 3 and ceria more difficult to reduce, likely due to Rh–Ni and Ce–Ni interactions. Adding ceria and nickel significantly improved the catalytic activity of Rh catalyst for propane conversion at 475 °C. Kinetic study at different temperatures (450–650 °C) indicated that the addition of ceria and Ni can greatly increase the propane reforming rates by lowering the activation energies from 67.6–68.8 kJ/mol for 2Rh/Al to 50.1–50.4 kJ/mol for 2Rh/20CeAl and to 42.1–42.5 kJ/mol for 2Rh5Ni/20CeAl. The feed steam/carbon molar ratios corresponding to maximum reaction rates at 475 °C increased from 2.0 for 2Rh/Al to 3.0 for 2Rh/20CeAl and 4.5 for 2Rh5Ni/20CeAl catalyst. A kinetic equation based on Langmuir–Hinshelwood model best fitting the experimental data was applied for the propane steam reforming over the Rh-based catalysts. Kinetic results at different partial pressures of propane and steam revealed that the addition of ceria could enhance the steam and propane adsorption, while the addition of Ni could significantly promote the propane adsorption, probably through working with Rh as propane adsorption sites.
Libraries and museums in virtual worlds: Adoption of immersive learning environments

This short paper describes progress on a current research project analyzing factors contributing to the adoption of virtual worlds by librarians, museum curators, and educators, during the era of rapid expansion of immersive learning in simulated computer environments. Both qualitative and quantitative methods were used to analyze survey data, using Everett Roger's Diffusion Theory as a theoretical framework. Survey questions were designed to address Roger's five attributes (relative advantage, compatibility, complexity, trialability, and observability). Results of the study will identify perceived benefits for the use of virtual worlds in educational settings of museums and libraries along with current predictors for adoption.
Assessment centres: keeping up with and getting ahead of changing organizations

Discusses assessment centres set up during the reorganization of the National Grid Company after privatization. Assessment centres are used to evaluate the skills and personal capabilities of employees. This allows the company to identify future talent, draw up personal development plans, evaluate training requirements and facilitate organizational change.
The importance of integrating risk in retrospective evaluations of research and development

The typical retrospective evaluation of a research and development program characterizes the social benefits of the results of the research and compares them with the social cost of the program. A positive result indicates a socially beneficial program and a negative result is seen as a poor use of resources. Although this approach yields substantial insight into the value of R&D investments, it yields an incomplete understanding of the phenomenon of interest because it neglects the risks of R&D projects. This article focuses on retrospective evaluations of R&D and argues that irrespective of whether the analyst is trying to understand the operation of the studied program or trying to develop generalizable knowledge to inform the design and predict the results of other nascent programs, risks and returns should always be considered together. More specifically, if a retrospective evaluation ignores risk, the validity of its results may be suspect. A review of guidelines for practitioners and examples from the literature demonstrate that risk is rarely considered in retrospective evaluations of R&D investments. In order to close this gap between a normative 'to-be' condition and an empirical 'as-is' condition, the feasibility of characterizing ex-ante risks in R&D projects is demonstrated and suggestions are made about how to conceptualize the construct of risk in relationship to returns. Methodologies from the fields of finance and risk assessment are presented as possible points of departure for incorporating risk and return when evaluating R&D initiatives. Implications for policymakers are also characterized. Copyright The Author 2012. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com, Oxford University Press.
The cancer biomarker problem

Genomic technologies offer the promise of a comprehensive understanding of cancer. These technologies are being used to characterize tumours at the molecular level, and several clinical successes have shown that such information can guide the design of drugs targeted to a relevant molecule. One of the main barriers to further progress is identifying the biological indicators, or biomarkers, of cancer that predict who will benefit from a particular targeted therapy.
Automatic method for identifying reaction coordinates in complex systems.

To interpret simulations of a complex system to determine the physical mechanism of a dynamical process, it is necessary to identify the small number of coordinates that distinguish the stable states from the transition states. We develop an automatic method for identifying these degrees of freedom from a database of candidate physical variables. In the method neural networks are used to determine the functional dependence of the probability of committing to a stable state (committor) on a set of coordinates, and a genetic algorithm selects the combination of inputs that yields the best fit. The method enables us to obtain the first set of coordinates that is demonstrably sufficient to specify the transition state of the C7eq→ αR isomerization of the alanine dipeptide in the presence of explicit water molecules. It is revealed that the solute−solvent coupling can be described by a solvent-derived electrostatic torque around one of the main-chain bonds, and the collective, long-ranged nature of this intera...
Expression of Hsp90 chaperome proteins in human tumor tissue

The activity of many oncogenic proteins depends on the molecular chaperone Hsp90. Recent studies indicate that tumorigenesis is associated with increased expression of chaperones, such as Hsp90. However, little is known about the isoform dependence and cochaperone contribution on tumor formation. Here we report the first systematic expression profiling for Hsp90alpha and Hsp90beta, the cochaperones Aha1, Cdc37, p23, Tpr2, and the Hsp90 dependent transcription factor HSF1 in a set of different tumor tissue samples. We find that in 10 out of 17 human tumors the expression level of at least one Hsp90 or Hsp90 cochaperone protein is significantly elevated. However, individual tumors show unique patterns of expression. Furthermore, Hsp90alpha and Hsp90beta expression levels are not related. Our results suggest that expression profiling of Hsp90alpha and Hsp90beta and its cochaperone proteins may be useful for cancer diagnosis and prognosis as well as for tailoring of drugs that interfere with the Hsp90 system in a tumor specific manner.
Noise in high-power, high-frequency double-tuned probes

Abstract Linear, nonlinear, and spurious noise sources are analyzed from the perspective of the design of high-power double-tuned NMR probes. An absolute efficiency is derived for simplified SNR comparison between various probes. A simple, accurate Q measurement technique based on 7 dB return loss is derived. A trilevel proton power decoupling scheme is proposed for reducing certain types of high-voltage noise, and the effects of various joining techniques on high-current shot noise are compared.
SU-E-J-210: Lung Tumor Target Volume Contours on EPID Cine Mode Images.

Purpose: While real time imaging of treatment through an electronic portal imaging device(EPID) is a powerful tool to monitor treatment, limited field of view and lower contrast from an MV beam can make assessment difficult for physicians. This work will develops a method to register and project contour outlines for the internal target volume (ITV) and planning target volume (PTV) of lungtumor cases onto cine mode EPIDimages to help physicians in interpretation during treatment. Methods: A sequence of EPIDimages, acquired during treatment, was registered to treatment planning computed tomography(CT) by machine geometry and patient setup with cone‐beam computed tomography(CBCT). The planning CT was converted from Hounsfield scale to electron density by calibration curves of our CT simulator and digitally reconstructed radiographs(DRRs) were produced to match the EPID geometry, pixel for pixel. ITV and PTV structures as defined on the planning CT were then projected onto the DRRs. The DRRs were registered to the EPIDimages using cross correlation of a single template defined within the treatment aperture of each image. Once registered, the contours from the DRR were transferred to the EPID.Results: We were able to successfully register MV DRRs to EPIDimages and display the projected target volumes. Without introduced motion, geometric registration and CBCT guided patient setup up were sufficient to register the contours within a single pixel, as normalized cross correlations produced no additional shift. We expect the DRR/EPID registration to be an important step when looking at cases with substantial tumor movement. Conclusions: The visualization of target volumes provides a tool for physicians to interpret EPIDimages and assess treatment, especially in cases with tumor movement. The methods developed will serve as the basis for a clinical tool providing real time contours.
Effect of lipid composition on the topography of membrane-associated hydrophobic helices: stabilization of transmembrane topography by anionic lipids.

Abstract To investigate the effect of lipid structure upon the membrane topography of hydrophobic helices, the behavior of hydrophobic peptides was studied in model membrane vesicles. To define topography, fluorescence and fluorescence quenching methods were used to determine the location of a Trp at the center of the hydrophobic sequence. For peptides with cationic residues flanking the hydrophobic sequence, the stability of the transmembrane (TM) configuration (relative to a membrane-bound non-TM state) increased as a function of lipid composition on the order: 1:1 (mol:mol) 1-palmitoyl-2-oleoyl- sn -glycero-3-phosphocholine (POPC):1-palmitoyl-2-oleoyl- sn -glycero-3-phosphoethanolamine ∼ 6:4 POPC:cholesterol sn -glycero-3-[phospho- rac -(1-glycerol)] sodium salt (DOPG) ≤ 1,2-dioleoyl- sn -glycero-3-[phospho- l -serine] sodium salt (DOPS), indicating that the anionic lipids DOPG and DOPS most strongly stabilized the TM configuration. TM stabilization was near maximal at 20–30 mol% anionic lipid, which are physiologically relevant values. TM stabilization by anionic lipid was observed for hydrophobic sequences with a diverse set of sequences (including polyAla), diverse lengths (from 12 to 22 residues), and various cationic flanking residues (H, R, or K), but not when the flanking residues were uncharged. TM stabilization by anionic lipid was also dependent on the number of cationic residues flanking the hydrophobic sequence, but was still significant with only one cationic residue flanking each end of the peptide. These observations are consistent with TM-stabilizing effects being electrostatic in origin. However, Trp located more deeply in DOPS vesicles relative to DOPG vesicles, and peptides in DOPS vesicles showed increased helix formation relative to DOPG and all other lipid compositions. These observations fit a model in which DOPS anchors flanking residues near the membrane surface more strongly than does DOPG and/or increases the stability of the TM state to a greater degree than DOPG. We conclude that anionic lipids can have significant and headgroup structure-specific effects upon membrane protein topography.
A multivariate predictor for total body calcium in man based on activation analysis.

Abstract A multivariate predictor employing height and total body potassium (lean body mass) for estimation of total body calcium is presented. The empirical relationship between these variables was derived in a study of 14 normal subjects analyzed by total-body neutron activation analysis. This relationship is as follows: for males: CaE = 54·6 H√K for females:CaE = 57·0 H√K This predictor was developed to provide a means of normalizing the body calcium data obtained for patients with various metabolic disorders. The ratios of measured total body Ca to predicted total body calcium were determined for 180 patients from 10 disease categories. The identification of skeletal abnormalities is a useful application of this technique in clinical studies.
Automated Detection of Inaccurate and Imprecise Transitions in Peptide Quantification by Multiple Reaction Monitoring Mass Spectrometry

Background: Multiple reaction monitoring mass spectrometry (MRM-MS) of peptides with stable isotope–labeled internal standards (SISs) is increasingly being used to develop quantitative assays for proteins in complex biological matrices. These assays can be highly precise and quantitative, but the frequent occurrence of interferences requires that MRM-MS data be manually reviewed, a time-intensive process subject to human error. We developed an algorithm that identifies inaccurate transition data based on the presence of interfering signal or inconsistent recovery among replicate samples. Methods: The algorithm objectively evaluates MRM-MS data with 2 orthogonal approaches. First, it compares the relative product ion intensities of the analyte peptide to those of the SIS peptide and uses a t -test to determine if they are significantly different. A CV is then calculated from the ratio of the analyte peak area to the SIS peak area from the sample replicates. Results: The algorithm identified problematic transitions and achieved accuracies of 94%–100%, with a sensitivity and specificity of 83%–100% for correct identification of errant transitions. The algorithm was robust when challenged with multiple types of interferences and problematic transitions. Conclusions: This algorithm for automated detection of inaccurate and imprecise transitions (AuDIT) in MRM-MS data reduces the time required for manual and subjective inspection of data, improves the overall accuracy of data analysis, and is easily implemented into the standard data-analysis work flow. AuDIT currently works with results exported from MRM-MS data-processing software packages and may be implemented as an analysis tool within such software.
Describing technological paradigm transitions: a methodological exploration

Much attention has been paid to the concept of the scientific or technological paradigm and, in particular, to the impact of change from one paradigm base to another. Discussion of paradigmatic shifts has been greatly hampered by the lack of appropriate tools for examining paradigms and their evolution. The sessio taurino technique presents an effective nonqualitative approach to describing changes in technological paradigms.
A test of the “messages‐as‐fixed‐effect fallacy” argument: Empirical and theoretical implications of design choices

Jackson and Jacobs (1983) reopened a debate, already long resolved by statisticians and linguists, that dealt with treating language variables as random versus fixed effects in analysis of variance designs. Jackson and Jacobs extended the argument to suggest that designs were invalid unless they included multiple messages within single experiments. An ensuing debate has filled scarce journal space, often advancing specious arguments, but at times offering sensible alternatives to the position that there is an invariant messages‐as‐fixed‐effect fallacy in our literature. Despite the lengthy debate, there has been no empirical scrutiny of relevant claims. Presented here is the first empirical test of three alternative analytic models using data from a carefully controlled experiment.
TEon-mode filters for the v.l.a. circular waveguide system

The design of a mechanically simple TEon (n ? 2) mode filter for overmoded circular waveguide is described. The filter operating from 26.14 to 47.85 GHz, presents a higher attenuation to all TEon-modes than any currently available alternative design.
1,2-Dichlorobenzene Interacting with Carbon Nanotubes

The interaction of 1,2-dichlorobenzene (DCB) with carbon nanotubes is analyzed by experimental and theoretical methods. Using first-principles calculations we studied the structural and electronic behavior of DCB interacting with a semiconductor (8,0) single-wall carbon nanotube (SWNT). We have found that the DCB weakly interacts with a perfect SWNT surface, but this interaction is slightly stronger when the SWNT surface has structural vacancies. Resonant Raman experiments performed on DCB-adsorbed SWNTs confirm the weak DCB−SWNT interaction, as suggested by the ab initio simulations.
Modeling shear-induced diffusion force in particulate flows

Abstract In this paper, a novel approach is presented to mechanistically model the dispersion of solid particles due to shear-induced diffusion effect. The model is based on the interfacial force concept, so that it is compatible with the ensemble averaged multifield model of multicomponent flows. Although the new model has been developed with membrane filtration processes in mind, the proposed shear-induced diffusion force formulation can be utilized to model a variety of industrial processes where particulates are present. The model has been verified against the other phenomenological models currently in use. The first part of this paper is concerned with theoretical aspects of model derivation. Then, a numerical analysis is presented to illustrate the application of the new model to dilute liquid/particle two-phase flows in tube membrane systems similar to those that are used for micro- and nano-filtration processes. The numerical simulations have been performed using a state of the art multiphase/multicomponent CFD code, NPHASE [Antal SP, Ettorre SM, Kunz RF, Podowski MZ. Development of a next generation computer code for the prediction of multicomponent multiphase flows. In: International meeting on trends in numerical and physical modeling for industrial multiphase flow, Cargese, France; 2000; Kunz RF, Yu WS, Antal SP, Ettorre SM. An unstructured two-fluid method based on the coupled phasic exchange algorithm. AIAA Paper 2001; 2001:2672]. The numerical consistency of the results of computer calculations have been verified against simplified semi-analytical approximations.
Adolescents' attention to responsibility messages in magazine alcohol advertisements: an eye-tracking approach.

Abstract Purpose To investigate whether adolescent readers attend to responsibility or moderation messages (e.g., "drink responsibly") included in magazine advertisements for alcoholic beverages and to assess the association between attention and the ability to accurately recall the content of these messages. Methods An integrated head-eye tracking system (ASL Eye-TRAC 6000) was used to measure the eye movements, including fixations and fixation duration, of a group of 63 adolescents (ages 12–14 years) as they viewed six print advertisements for alcoholic beverages. Immediately after the eye-tracking sessions, participants completed a masked-recall exercise. Results Overall, the responsibility or moderation messages were the least frequently viewed textual or visual areas of the advertisements. Participants spent an average of only .35 seconds, or 7% of the total viewing time, fixating on each responsibility message. Beverage bottles, product logos, and cartoon illustrations were the most frequently viewed elements of the advertisements. Among those participants who fixated at least once on an advertisement's warning message, only a relatively small percentage were able to recall its general concept or restate it verbatim in the masked recall test. Conclusions Voluntary responsibility or moderation messages failed to capture the attention of teenagers who participated in this study and need to be typographically modified to be more effective.
Comparison of EVAR and open repair in patients with small abdominal aortic aneurysms: Can we predict results of the PIVOTAL trial?

Objective Data from multicenter studies support observation of small abdominal aortic aneurysms (AAAs) over open repair (OR), but the role of endovascular repair (EVAR) is unclear pending outcome of the Positive Impact of EndoVascular Options for Treating Aneurysm earLy (PIVOTAL) trial. Our goal was to predict the outcome of the trial by comparing results of small AAA repair using EVAR vs OR at a tertiary institution. Methods Using selection criteria of PIVOTAL trial, we reviewed clinical data of 194 consecutive patients, who underwent EVAR or OR for 4.0-5.0 cm AAAs between 1997 and 2004. All-cause and aneurysm-related deaths, complications, reinterventions, ruptures, and conversions were documented; factors affecting outcome were analyzed using χ 2 tests, Wilcoxon rank-sum tests, logistic regression Kaplan-Meier method with log-rank tests, and Cox proportional hazards regression. Median follow-up was 3.9 years (range, 1 month to 9 years). Results A total of 194 patients, 162 males, 32 females (mean age: 71 years, range, 46-86) underwent 162 OR and 32 EVAR. EVAR patients were older (mean 74 ± 6 vs 71 ± 7, P = .002), had lower ejection fraction (mean 54 ± 11 vs 61 ± 13, P = .0002), and less likely to have ever smoked (69% vs 85%, P = .03) than OR patients. Thirty-day mortality was 1.3% (2/162) for OR and 0% for EVAR (0/33) ( P = not significant [NS]). There were 49 systemic complications (7 EVAR, 42 OR, P = NS) and 10 local complications (3 EVAR, 7 OR, P = NS). During follow-up, there were no conversions and no ruptures. Freedom from reinterventions at 5 years was 83.1% ± 6.9% for EVAR and 95.3% ± 1.8% for OR ( P = 0.02). There were 26 deaths (3 EVAR, 23 OR); but no procedure or aneurysm-related death was confirmed after 30 days (cause unknown in 16 deaths, 62%). Survival rates at 1-year were 96.6% ± 3.4% for EVAR and 97.4% ± 1.3% for OR; 5-year rates were 86.9% ± 7.2% ± EVAR and 86.9% ± 3.3% for OR ( P = 0.69). Multivariate analysis revealed age (hazard ratio=1.1 per year, P = .0496) and AAA size (hazard ratio=13.8 per 1 cm, P = .03) were associated with death but EVAR vs OR was not ( P = .23). Conclusion For repair of small AAAs, results of EVAR vs OR are not different at 5 years at a tertiary institution. Multicenter studies confirmed OR were not superior to observation in these patients. We predict the PIVOTAL study will conclude EVAR is not superior to observation.
Coulomb displacement energies of the T = 1, J = 0 states of A = 42 nuclei☆

Abstract Coulomb displacement energies of the T = 1, J = 0 + and 6 1 + states of A = 42 nuclei are analyzed with previously known charge dependent forces and effects, and with the available HartreeFock single-particle wave functions. From the study of the Coulomb displacement energies of the 6 1 + states, it is found that the present knowledge on the charge dependence, including a phenomenological charge symmetry breaking force previously introduced so as to help explain the Nolen-Schiffer anomaly, gives a sufficient and consistent explanation for both single-particle and twoparticle systems. From the study of the 0 + states, we found that the Coulomb displacement energies of the second 0 2 + states can be explained with a compensation between the smaller Coulomb energies of the second lowest two-particle state and larger ones of the deformed 4p-2h state.
Silicon tissue assays in nonaugmented cadaveric patients: is there a baseline level?

Microscopic silicone in various tissues in the bodies of females with breast implants has led to the possible incrimination of these implants with connective-tissue disorders. Current technology precludes accurate silicone measurements, but all compounds containing the element silicon (which would include silicone) may be measured accurately. Direct positive correlations of silicon assays with silicone measured levels were confirmed by adding known amounts of silicone oil as a control. With the ubiquitous nature of organosilicons (food containers, syringes, etc.), we hypothesized that baseline silicon levels could be detected in tissues of cadavers without silicone breast augmentation
Progressive amplification and overexpression of the eukaryotic initiation factor 4E gene in different zones of head and neck cancers.

Purpose: Eukaryotic initiation factor 4E (eIF4E) binds to mRNA as the initial rate-limiting step in protein synthesis. Amplification and overexpression of the eIF4E gene has been associated with malignant transformation. The objectives of this study were to 1) quantify the eIF4E gene in head and neck squamous cell carcinoma (HNSCC) specimens, 2) quantify eIF4E protein elevation and examine its association with eIF4E gene amplification, and 3) determine whether there is progression in eIF4E gene amplification and protein overexpression in the tumor-free resection margin, the transition zone, and the tumor core of HNSCC specimens. Materials and Methods: Eighteen HNSCC specimens were divided into three zones: 1) tumor core; 2) transition zone; and 3) “tumor-free” margin. Competitive polymerase chain reaction was performed to determine eIF4E gene copy number. eIF4E protein expression was quantified using Western blot analysis. Results: All 18 HNSCC specimens tested had significant eIF4E gene amplification (4.3 ± 1.2; P < .05). In contrast, none of the 10 benign specimens from noncancer patients had any eIF4E gene amplification (1.1 ± 0.5). In the 12 HNSCC specimens examined for the three zones, the tumor core and transition zone showed eIF4E gene amplification (5.2 ± 1.1 and 3.5 ± 0.9, respectively) compared with the “tumor-free” margin (2.1 ± 1.1; P < .05). The tumor core and transition zone showed significant eIF4E protein elevation (15.5 ± 9.3, 4.4 ± 4.6, respectively) compared with the “tumor-free” margin (0.9 ± 0.5, P < .05). Conclusions: The eIF4E gene is amplified and overexpressed in HNSCC. Amplification and elevation of eIF4E were highest in the tumor core, intermediate in the transition zone, and lowest in the tumor-free margin. There appears to be progression of eIF4E gene amplification and overexpression from the “tumor-free” margin to the tumor core.
Cyclic stretch stimulates vascular smooth muscle cell alignment by redox-dependent activation of Notch3

Mice deficient in Notch3 have defects in arterial vascular smooth muscle cell (VSMC) mechanosensitivity, including impaired myogenic responses and autoregulation, and inappropriate VMSC orientation...
Cyclic Nucleotide Content of Passaged Keratinocytes in Culture During Various Growth Stages

Human newborn foreskin keratinocytes were maintained in culture in first passage for up to 60 days. An initial lag phase was followed by a growth and a final plateau phase. During this time, cell numbers, the morphologic appearance of both attached and detached cells, DNA, and cyclic nucleotide content were evaluated. Cell cycle analysis during growth phase was performed by flow cytofluorometry. High levels of cAMP and cGMP coincided with the early growth phase, when up to 70% of cells were in S, G 2 , or M compartments of the cell cycle. Halfway through growth phase, a fall in cyclic nucleotide levels coincided with a drop in mitotic index and increase in G 1 cells. Plateau phase was characterized by increased desquamation, a gradual elevation of intracellular cAMP, cGMP, and DNA, and in later stages, an increased proportion of squamous cells in the attached layers. The oldest cultures were mostly squamous with low cyclic nucleotide levels. Results suggest that high cyclic nucleotide content is a feature of cycling, possibly S phase keratinocytes. Onset of differentiation coincides with a small but definite increase in both cAMP and cGMP, which in general vary in the same direction.
Relaxation of solvent protons and deuterons by protein-bound Mn2+ ions. Theory and experiment for Mn2+-concanavalin A

Abstract Despite the demonstrated utility of measurements of the magnetic field dependence of the magnetic relaxation rates of solvent protons in solutions of metalloproteins as an indicator of biochemical changes, it is becoming increasingly evident that quantitative comparisons of such data with the theory of relaxation, limited by the approximations and assumptions usually made, yield results for the strength of the solvent-paramagnetic ion interaction that generally do not make chemical sense. These results, when expressed as the number of solvent-donated ligands of the ions, usually give too large a value, typically by about twofold. It has been suggested by several investigators that a comparison of proton and deuteron relaxation rates could resolve the problem. Data are presented for the longitudinal relaxation rates of solvent protons and deuterons over more than four decades of magnetic field (from 0.01 to 270 MHz proton Larmor frequency) for solutions of Mn2+-concanavalin A, a protein for which the physical biochemistry is thoroughly documented, one that should be particularly tractable for such comparisons. The main conclusion is that, in the general case, there is no decade of magnetic field over which the mathematical criterion of best agreement of data with theory can be relied upon to yield quantitatively correct biochemical results; rather, biochemistry must still be a guide for elucidating relaxation pathways.
Impedance analysis of amorphous and polycrystalline tantalum oxide sputtered films

Impedance spectroscopy studies were conducted on amorphous tantalum oxide thin films prepared using pulsed-DC reactive sputtering, which were post-annealed to crystallize the films. X-ray diffraction results showed that crystallization to Ta2O5 β phase occurs for samples annealed above 650 °C, with a crystallite size of ∼40 nm. The film microstructure was studied by electron microscopy, and remnants of the columnar amorphous microstructure were found in the polycrystalline films. Complex impedance analyses revealed significant differences in dielectric behavior between the amorphous and crystalline films. Lumped circuit models were conducted on the films using resistors, capacitors, and constant phase elements. Amorphous films exhibited a single relaxation with Arrhenius activation energy of 1.1–1.3 eV. Crystallized films exhibited two relaxations with activation energies equal to 1.1 ± 0.08 and 0.6 ± 0.03 eV. The relative permittivity of the bulk crystalline grain in tantalum oxide films is close to the established permittivity of the β phase (er = 40) of Ta2O5.
Emergent complexity in simple neural systems

The ornate and diverse patterns of seashells testify to the complexity of living systems. Provocative computational explorations have shown that similarly complex patterns may arise from the colle...
The media influence debate: Read the fine print, but don't lose sight of the big picture

O Reading the Kozma and Clark pieces in this issue has convinced me of at least one point: the debate regarding the influence of media on learning is not the instructional technologists' version of "how many angels can dance on the head of a pin"; I disagree with those who are impatient with the argument and who wish to dismiss it as unimportant. The debate has merit because it helps us to clarify who we are, what we are trying to do, what we know, and how we might best invest the limited resources devoted to future research.
Economic Development and the Developmental State: Assessing the Development Experiences of Ghana and Malaysia since Independence

This article presents evidence on the divergent development experiences of Ghana and Malaysia. Various demographic, social, and development indicators are carefully analyzed. Factors that explain M...
E-cigarette use among smokers with serious mental illness

Background We examined electronic cigarette (EC) use, correlates of use, and associated changes in smoking behavior among smokers with serious mental illness in a clinical trial. Methods Adult smokers were recruited during acute psychiatric hospitalization (N = 956, 73% enrollment among approached smokers) in the San Francisco Bay Area between 2009–2013. At baseline, participants averaged 17 (SD = 10) cigarettes per day for 19 (SD = 14) years; 24% intended to quit smoking in the next month. Analyses examined frequency and correlates of EC use reported over the 18-month trial and changes in smoking behavior by EC use status. Findings EC use was 11% overall, and by year of enrollment, increased from 0% in 2009 to 25% in 2013. In multiple logistic regression, the likelihood of EC use was significantly greater with each additional year of recruitment, for those aged 18–26, and for those in the preparation versus precontemplation stage of change, and unlikely among Hispanic participants. EC use was unrelated to gender, psychiatric diagnosis, and measures of tobacco dependence at baseline. Further, over the 18-month trial, EC use was not associated with changes in smoking status or, among continued smokers, with reductions in cigarettes per day. Interpretation Within a clinical trial with smokers with serious mental illness, EC use increased over time, particularly among younger adults and those intending to quit tobacco. EC use was unrelated to changes in smoking. The findings are of clinical interest and warrant further study.
Book Review: Compassion in Human Nature

Book reviewed in this article: R. J. Davidson and A. Harrington (eds.), Visions of Compassion: Western Scientists and Tibetan Buddhists Examine Human Nature
Cytogenetic studies in mammalian somatic cells exposed to electromagnetic fields: A meta-analysis

Several researchers have examined the extent of genetic damage in mammalian somatic cells exposed in vitro and/or in vivo exposure of extremely low frequency (ELF) and radiofrequency (RF) electromagnetic fields. A meta-analysis of all data reported for chromosomal aberrations in human and animal cells during the last several years (1990–2007 for ELF and 1990–2005 for RF) was conducted to obtain a ‘quantitative’ estimate (with 95% confidence interval) of chromosomal aberrations in ELF/RF-exposed cells and compared with that in control cells. The influence of three specific variables was considered in the meta-analysis: (i) frequency, (ii) flux density (for ELF) and specific absorption rate (for RF), and (iii) exposures as continuous wave, pulsed wave and occupationally-exposed individuals. The overall data indicated that (a) the difference between ELF/RF-exposed and control cells was very small, (b) multiple regression and heterogeneity tests indicated that the factors which were not considered in this meta-analysis had an influence on the difference between ELF/RF-exposed and control cells and (c) the mean indices for chromosomal aberrations in all cells were within the spontaneous levels reported in a historical database.
Laser-assisted coronary angioplasty in patients with severely depressed left ventricular function: quantitative coronary angiography and clinical results.

Laser-assisted coronary angioplasty can be successfully applied to lesions not ideal for balloon angioplasty. Patients with severely impaired left ventricular (LV) function and complex coronary artery stenoses who call for percutaneous revascularization are considered a high risk group for balloon angioplasty. In order to determine the feasibility, safety, and acute clinical outcome of a solid state, pulsed wave, mid-infrared (2.1 micron) laser facilitated angioplasty in these patients, data from 112 patients with 129 lesions were analyzed. Patients were identified according to angiographic LV function; group I included 22 patients with left ventricular ejection fraction (LVEF) or = 40% (mean = 58% +/- 8%). No difference in age, gender, diabetes, hypertension, tobacco use, history of previous coronary artery bypass surgery (CABGS) or percutaneous transluminal coronary angioplasty was registered between the two groups. Multivessel disease, previous myocardial infarction (MI), and severe angina were more prevalent among group I patients (P = 0.03). No difference was found in lesion location, complexity, length, or calcification between the two groups; although group I had more eccentric lesions. Both groups were treated with the same laser energy level followed by adjunctive balloon angioplasty. One hundred percent procedural success was obtained in group I versus 93% in group II (P = NS). By Q.C.A. (independent core lab), minimal luminol diameter increased in group I from 0.9 +/- 0.5 mm preprocedure to 2.0 +/- 0.5, as compared to 0.8 +/- 0.5 mm to 1.9 +/- 0.5 mm (P = NS) in group II. Stenosis severity improved from 69% +/- 16% preprocedure to 37% +/- 13% postprocedure in group I, as compared to improvement from 78% +/- 16% to 37% +/- 12.7% in group II (P = NS). Overall complication rate was remarkably low, with no death or perforation in either group; emergency CABGS 0% in group I and 1.1% in group II; dissections 4.5% in group I and 8.8% in group II. There was no significant difference in complication rate between the two groups. The results of this study suggest that holmium:YAG laser facilitated coronary angioplasty can be safely performed in patients with severe LV dysfunction, achieving a remarkably high procedural success and low complication rate.
PALEOCOASTAL LITHIC USE ON WESTERN SANTAROSAE ISLAND, CALIFORNIA*

California’s Northern Channel Islands have produced several Paleocoastal assemblages that include some of the most intricate and finely crafted lithic technologies in the Americas. Current understanding of chert use and availability on the islands comes primarily from research on Late Holocene sites from Santa Cruz Island, where chert sources played an important role in providing microdrills for Late Holocene Olivella bead production. New data from Terminal Pleistocene and Early Holocene sites suggest that Paleocoastal peoples relied heavily on other cherts from San Miguel and Santa Rosa islands. To examine the deeper history of lithic use on the islands, we analyzed eight Paleocoastal lithic assemblages from San Miguel and Santa Rosa, which were part of the larger island of Santarosae until about 10,000 years ago. We discuss lithic availability and material preference for formal and expedient stone tool manufacture on the Northern Channel Islands between ~12,000 and 7,500 years ago.
PLANT GROWTH STIMULATION BY SUBLETHAL CONCENTRATIONS OF HERBICIDES

Summary. Significant stimulation of root or shoot growth of oats (Avena sativa L.) resulted from pre-emergence applications of eleven herbicides at sublethal doses. Two additional herbicides stimulated cucumber (Cucumis sativus L.) root growth. Several types of herbicides with different mechanisms of lethal action were represented. Three herbicides failed to stimulate plant growth significantly in these studies, although all of them have been observed to cause growth stimulation in other experiments. Studies on oat seedling respiration, photosynthesis, protein content, free amino acid content, and total available soluble carbohydrates failed to provide any consistent explanation for stimulation. These results provide further evidence of the validity of the Arndt-Schulz hypothesis which states that all poisons are stimulatory at sublethal concentrations. Stimulation de la croissance des plantes par des concentrations subletales d'herbiddes Resume. Une stimulation significative de la croissance des racines ou des tiges de I'avoine (Avena sativa L.) a ete provoquee par l'application en pre-levee de onze herbicides a des doses subletaies. Deux autres herbicides ont stimule la croissance des racines de concombre. Plusieurs types d'herbicides possedant des mecanismes diffrents d'action letale etaient representes. Trois herbicides n'ont pas provoque de stimulation significative de la croissance au cours de cette etude, bien qu'ils aient provoque une stimulation dans d'autres experiences. Des recherches sur la respiration, la photosynthese, la teneur en proteines, en amino-acides libres et le total disponible des hydrates de carbone solubles dans la plantule d'avoine n'ont fourni aucune explication logique de la stimulation. Ces resultats apportent une nouvelle preuve de la validite de l'hypothese d'Arndt-Schulz selon laquelle tous les poisons ont un effet stimulant a des concentrations subletaies. Forderung des Pflanzenwachstums durch Herbizide in sublethalen Konzentrationen Zusammenfassung. Die Vorauflaufanwendung von elf Herbiziden in sublethalen Dosen forderte das Wurzel- und Sprosswachstum von Hafer (Avena sativa L.) signifikant. Zwei weitere Herbizide stimulierten das Wurzelwachstum bei der Gurke (Cucumis sativus L.). Es waren Herbizide aus verschiedenen Gruppen mit unterschiedlichem Mechanismus der lethalen Wirkung vertreten. Drei Herbizide forderten in diesen Studien das Wachstum nicht signifikant, obwohl eine solche fordernde Wirkung in anderen Experimenten beobachtet worden war. Untersuchungen der Atmung von Haferkeimlingen, der Photosynthese, des Proteingehaltes, des Gehaltes an freien Aminosauren und der Gesamtmenge an loslichen Kohlenhydraten erbrachten keine einheitliche Erklarung fur die Forderung. Diese Ergebnisse stutzen die Gultigkeit der Arndt-Schulz Hypothese, die besagt, dass alle Gifte in sublethalen Dosen stimulierend wirken.
Testicle size of orang-utans in relation to body size.

Few data are available for assessing the relative testicle size of orang-utans, Pongo pygmaeus, so measures were obtained for 31 individuals of varying age. It was shown that the volume of the testicles, calculated from in situ measures of testicle length and breadth, closely approximates testicle weight when multiplied by the specific gravity of solid tissue. Growth curves for body weight and data published for wild specimens were evaluated to obtain the weight most characteristic of male Pongo, and the ratio of testicle weight to body weight was calculated. The mean ratio for individuals with fully adult stature is 0.034, similar to but smaller than that of humans at about 0.050, and larger than the ratios reported for 5 gorillas at 0.013. The testicles mature faster than the body, however, so the mean ratio for young adult orang-utans is about 0.056 and resembles the ratio for humans more closely than the full adults. The differences between the ratios for a monogamous gibbon species, orang-utans, and humans is accounted for when testicle size relative to the weight of the female is considered. This is consistent with a sperm dilution effect produced by variation in the size of the female reproductive tract. The small relative testicle size of the gorilla is anomalous and requires verification as does the application of female size to scale the testicles. © 1993 Wiley-Liss, Inc.
Spatial patterns of surface hoar properties and incoming radiation on an inclined forest opening

Avalanche hazard evaluation relies in part on representative snowpack stability obser- vations. Thus, understanding the spatial patterns of snowpack instabilities and their environmental determinants is crucial. This case study integrates intensive field observations with spatial modeling to identify associations between incoming radiation, surface hoar development and its subsequent shear strength across an inclined forest opening. We examined a buried surface hoar layer in southwest Montana, USA, over five sampling days, collecting 824 SnowMicroPen resistance profiles and performing 352 shear frame tests. Spatial models of incoming long- and shortwave radiation were generated for the surface hoar formation period using modeled hemispheric sky visibility, physically based parameters and the Bird Clear Sky Radiation Model in a Geographic Information System. Before burial, the surface hoar persisted despite moderate winds and relatively high air temperatures. The buried surface hoar layer thickness varied between 3 and 21 mm within a distance of 30 m. Modeled incoming radiation explained spatial variations in layer thickness and shear strength. In areas exposed to large amounts of radiation, the surface hoar layer was strong and thin, while areas with limited incoming radiation (due to high sky visibility and shading) possessed a thicker surface hoar layer that sheared more easily. This demonstrates the usefulness of microclimate modeling for slope-scale avalanche hazard evaluation. We also identify that over the 3 week sample period, strengthening occurred without thinning of the surface hoar layer.
Atypical epithelial cells and specimen adequacy: current laboratory practices of participants in the college of American pathologists interlaboratory comparison program in cervicovaginal cytology.

Abstract Context.—The Bethesda System for reporting cervical/vaginal cytologic diagnoses introduced terminology for atypical squamous and glandular cells and categories for specimen adequacy. Objectives.—To analyze current laboratory reporting practices and compare trends to previous surveys. Design.—Questionnaire surveys were mailed to 2000 laboratories in 1996 and 1997. Participants.—Laboratories enrolled in the College of American Pathologists Interlaboratory Comparison Program in Cervicovaginal Cytology. Main Outcome Measures.—Laboratory policies, criteria, and reporting rates for Bethesda System categories. Results.—The 1996 specimen adequacy survey had 1166 respondents, and 768 laboratories returned the 1997 questionnaire focusing on atypical squamous cells of undetermined significance (ASCUS) and glandular cells of undetermined significance (AGUS). Nearly all laboratories (92%) routinely reported specimen adequacy, an increase from the 66% rate in 1991. The median rate for unsatisfactory specimens ...
Biodegradation of low-molecular-weight halogenated hydrocarbons by methanotrophic bacteria

Low-molecular-weight halogenated hydrocarbons are susceptible to degradation by anaerobic and aerobic bacteria. The methanotrophic bacterium Methylosinus trichosporium 0B3b degrades trichloroethylene more rapidly than other bacteria examined to date. Expression of soluble methane monooxygenase (MMO) is correlated with high rates of biodegradation. An analysis of 16 S rRNA sequences of 11 ribosomal RNAs from type I, type II and type X methanotrophs and methanol-utilizing bacteria have revealed four clusters of phylogenetically related methylotrophs. This information may be useful for the identification and enumeration of methylotrophs in bioreactors and other environments during remediation of contaminated waters.
The Jaw of the Worm: GTPase-activating Protein EAT-17 Regulates Grinder Formation in Caenorhabditis elegans

Constitutive transport of cellular materials is essential for cell survival. Although multiple small GTPase Rab proteins are required for the process, few regulators of Rabs are known. Here we report that EAT-17, a novel GTPase-activating protein (GAP), regulates RAB-6.2 function in grinder formation in Caenorhabditis elegans. We identified EAT-17 as a novel RabGAP that interacts with RAB-6.2, a protein that presumably regulates vesicle trafficking between Golgi, the endoplasmic reticulum, and plasma membrane to form a functional grinder. EAT-17 has a canonical GAP domain that is critical for its function. RNA interference against 25 confirmed and/or predicted RABs in C. elegans shows that RNAi against rab-6.2 produces a phenotype identical to eat-17. A directed yeast two-hybrid screen using EAT-17 as bait and each of the 25 RAB proteins as prey identifies RAB-6.2 as the interacting partner of EAT-17, confirming that RAB-6.2 is a specific substrate of EAT-17. Additionally, deletion mutants of rab-6.2 show grinder defects identical to those of eat-17 loss-of-function mutants, and both RAB-6.2 and EAT-17 are expressed in the terminal bulb of the pharynx where the grinder is located. Collectively, these results suggest that EAT-17 is a specific GTPase-activating protein for RAB-6.2. Based on the conserved function of Rab6 in vesicular transport, we propose that EAT-17 regulates the turnover rate of RAB-6.2 activity in cargo trafficking for grinder formation.